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This paper presents the synthesis of visible light-responsive ternary nanocomposites composed of cuprous oxide (Cu 2 O), tungsten trioxide (WO 3), and titanium dioxide (TiO 2) with varying weight percentages (wt.%) of the Cu 2 O. The resulting Cu 2 O/WO 3 /TiO 2 (CWT) nanocomposites exhibited band gap energy ranging from 2.35 to 2.90 eV. Electrochemical and photoelectrochemical (PEC) studies confirmed a reduced recombination rate of photoexcited charge carriers in the CWT nanocomposites, facilitated by a direct Z-scheme heterojunction. The 0.50CWT nanocomposite demonstrated superior photodegradation activity (2.29 × 10−2 min−1) against Reactive Black 5 (RB5) dye under visible light activation. Furthermore, the 0.50CWT nanocomposite exhibited excellent stability with 80.51% RB5 photodegradation retention after five cycles. The 0.50CWT electrode achieved a maximum specific capacitance of 66.32 F/g at 10 mA/g current density, with a capacitance retention of 95.17% after 1000 charge-discharge cycles, affirming its stable and efficient supercapacitor performance. This was supported by well-defined peaks in cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) curves, indicating pseudocapacitive properties. • Direct Z-scheme heterojunction facilitates separation of photoexcited charge carriers. • Photoelectrochemical study proved reduction of charge carriers recombination rate. • Nanocomposite showed excellent chemical and photostability for dye photodegradation. • Chemical oxygen demand test proved complete mineralization of dye by photocatalysis. • High capacitance retention and specific capacitance proved effective supercapacitor. [ABSTRACT FROM AUTHOR]

This research focuses on the synthesis and application of a novel kaolin-supported g-C 3 N 4 /MoO 3 nanocomposite for the degradation of tetracycline, an important antibiotic contaminant in water systems. The nanocomposite was prepared through a facile and environmentally friendly approach, leveraging the adsorption and photocatalytic properties of kaolin, g-C 3 N 4 and MoO 3 nanoparticles, respectively. Comprehensive characterization of the nanocomposite was conducted using techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and optical spectra. The surface parameters were studied using N 2 adsorption-desorption isotherm. The elemental composition was studied using X-ray photoelectron spectroscopy. The efficiency of the developed nanocomposite in tetracycline degradation was evaluated and the results revealed an efficient tetracycline degradation exhibiting the synergistic effects of adsorption and photocatalytic degradation in the removal process. The tetracycline degradation was achieved in 60 min. Kinetic studies and thermodynamic analyses provided insights into the degradation mechanism, suggesting potential applications for the nanocomposite in wastewater treatment. Additionally, the recyclability and stability of the nanocomposite were investigated, demonstrating its potential for sustainable and long-term application in water treatment. • Kaolin supported g-C 3 N 4 @MoO 3 ternary nanocomposites have been synthesized for waste water treatment. • The nanocomposites have been characterized by several analytical techniques. • The influence of various parameters in the degradation of tetracycline is explored. • The degradation using Z-scheme unveiling the synergistic effects of adsorption and photocatalytic degradation. [ABSTRACT FROM AUTHOR]

The removal of organic pollutants in water environments and the resource utilization of solid waste are two pressing issues around the world. Facing the increasing pollution induced by discharge of mining effluents containing sodium isopropyl xanthate (SIPX), in this work, municipal solid waste incineration fly ash (MSWI FA) was pretreated by hydrothermal method to produce stabilized FA, which was then innovatively used as support for the construction of FA/TiO 2 /BiOCl nanocomposite (FTB) with promoted photocatalytic activity under visible light and natural sunlight. When the content of FA was 20 wt% and the mass ratio of TiO 2 to BiOCl was 4:6, a remarkable performance for the optimal FTB (20-FTB-2) was achieved. Characterizations demonstrated that TiO 2 and BiOCl uniformly dispersed on FA contributing to high surface area and broad light adsorption of FTB, which exhibits excellent adsorption capacity and light response ability. Build in electric field formed in the interface of TiO 2 /BiOCl heterojunction revealed by density functional theory calculations accelerated the separation of photoinduced e− and h+, leading to high efficiency for SIPX degradation. The synergetic effect combined with adsorption and photocatalytic degradation endowed 20-FTB-2 superior SIPX removal efficiency over 99% within 30 min under visible light and natural sunlight irradiation. The photocatalytic degradation pathways of SIPX were determined through theoretical calculations and characterizations, and the toxic byproduct CS 2 was effectively eliminated through oxidation of •O 2 −. For 20-FTB-2, reusability of photocatalyst was showed by cycle tests, also the concentrations of main heavy metals (Pb, Zn, Cu, Cr, and Cd) in the liquid phases released during photocatalyst preparation process (< 1 mg/L) and photodegradation process (< 8.5 μg/L) proved the satisfactory stability with low toxicity. This work proposed a novel strategy to develop efficient and stable support-based photocatalysts by utilizing MSWI FA and realize its resource utilization. [Display omitted] • Stabilized FA supported the construction of FA/TiO 2 /BiOCl heterojunction composite. • Optimized 20-FTB-2 exhibited superior photocatalytic degradation of SIPX (>99.9%). • Heavy metals in FTB leached out hardly during photocatalytic degradation process. • Fly ash-supported photocatalyst enhanced adsorption and photocatalytic capability. • Detailed photocatalytic mechanism and degradation pathway of SIPX were proposed. [ABSTRACT FROM AUTHOR]

Removing the algae from water bodies is an effective treatment toward the worldwide frequently occurred harmful algae blooms (HAB), but processing the salvaged algae waste without secondary pollution places another burden on the economy and environment. Herein, a green hydrothermal process without any chemical addition was developed to resource the HAB algae (Microcystis sp.) into autogenous nitrogen and sulfur co-doped carbon nanosheet materials C–CNS and W–CNS, whose alga precursors were collected from pure culture and a wild bloom pond, respectively. After coupling with CeO 2 , the obtained optimal C–CNS/CeO 2 and W–CNS/CeO 2 composites photocatalytically degraded 95.4% and 88.2% of the marine pollutant 4,5-Dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) in 90 min, significantly higher than that of pure CeO 2 (63.15%). DCOIT degradation on CNS/CeO 2 was further conducted under different conditions, including pH value, coexisting cations and anions, and artificial seawater. Although different influences were observed, the removal efficiencies were all above 76%. Along with the ascertained good stability and reusability in five consecutive runs, the great potential of CNS/CeO 2 for practical application was validated. UV–vis DRS showed the increased light absorption of CNS/CeO 2 in comparison to pure CeO 2. PL spectra and photoelectrochemical measurements suggested the lowered charge transfer resistance and thereby inhibited charge recombination of CNS/CeO 2. Meanwhile, trapping experiments and electron paramagnetic resonance (EPR) detection verified the primary roles of hydroxyl radical (OH) and superoxide radical (O 2 −) in DCOIT degradation, as well as their notably augmented generation by CNS. Consequently, a mechanism of CNS enhanced photocatalytic degradation of DCOIT was proposed. The intermediates involved in the reaction were identified by LC-QTOF-MS, giving rise to a deduced degradation pathway for DCOIT. This study offers a new approach for resourceful utilization of the notorious HAB algae waste. Besides that, photocatalytic degradation has been explored as an effective measure to remove DCOIT from the ocean. [Display omitted] • Harmful algae waste was derived to nitrogen, sulfur co-doped carbon nanosheet (CNS). • CNS modified CeO 2 exhibited the significantly enhanced photocatalytic activity. • CNS improved the charge separation and light absorption of CeO 2. • 95.4% of DCOIT could be removed by optimal CNS/CeO 2 in 90 min. • DCOIT degradation under ocean related conditions and pathway were investigated. [ABSTRACT FROM AUTHOR]

The aim of this paper is to investigate the derived structure and properties of Zeolitic Imidazolate Framework-8 (ZIF-8), and the effect of residual structural on the catalytic properties after loading with Titanium Dioxide (TiO 2). For this purpose, we ingeniously prepare C-ZIF-8@TiO 2 with a transition-state defect structure and apply it for efficiently degrading organic dye wastewater represented by Rhodamine B (Rh–B). Thanks to the transition-state defect structure loaded with TiO 2 and ZIF-8 self-derived Carbon (C) and Zinc Oxide (ZnO), the catalytic performance of C-ZIF-8@TiO 2 is superior to that of TiO 2 and normal TiO 2 /ZIF-8 composites, and it is effective in degrading a variety of antibiotics and dyes. The related characterization also shows good photovoltaic properties and long-term durability for C-ZIF-8@TiO 2. The mechanism on free radical action is elucidated and the possible degradation pathway for Rh–B is speculated. Therefore, C-ZIF-8@TiO 2 provides a new strategy for the degradation of organic pollutants in water bodies. • A multidimensional catalytic system was created due to self-derived C and ZnO. • The transition-state defect structure formed using ZIF-8 as a carrier. • C-ZIF-8@TiO 2 effectively degrades a variety of antibiotics and dyes. [ABSTRACT FROM AUTHOR]

A morphological oriented highly active Cu 2 O–Ag–CaWO 4 (CAC) nano-heterojunction was fabricated for the visible light driven degradation of rifampicin (RFP). Octahedron shaped Cu 2 O being a base material, where the Tagetes shaped CaWO 4 and Ag were embedded on it. The shape-controlled morphology of Cu 2 O and CaWO 4 as well as Ag decoration influence high degree of adsorption of RFP and interfacial charge transfer between the nano-heterojunction. Further, the larger specific surface area (129.531 m2/g) and narrow band gap energy (2.57 eV) of CAC nano-heterojunction than the controls support the statement. Positively, CAC nano-heterojunction following Z-scheme-type charge transport mechanism attained 96% of RFP degradation within 100 min. O 2 •- and •OH are the primarily involved reactive oxidation species (ROS) during the photocatalytic reactions, determined by scavenger study and ESR analysis. The stability and reusability of the CAC nano-heterojunction was assessed through performing cyclic experiment of RFP degradation and it holds 96.8% of degradation even after 6th cycle. The stability of CAC nano-heterojunction after photodegradation was further confirmed based on crystalline pattern (XRD analysis) and compositional states (XPS analysis). Intermediates formed during RFP degradation and its toxicity was discovered by using GC-MS/MS and ECOSAR analysis respectively. The end-product toxicity against bacterial system and genotoxicity of CAC nano-heterojunction against Allium cepa were evaluated and the results were seemed to have no negative causes for the aquatic lives. • CAC nano-heterojunction with Z-scheme-type charge transport mechanism was fabricated for RFP degradation. • CAC nano-heterojunction attained 96% of RFP degradation within 100 min. • O 2.•- and •OH are the primarily involved ROS during the photocatalytic reactions. • Degradation pathway was proposed using GC-MS/MS analysis. • Toxicity studies against bacterial system and Allium cepa was employed. [ABSTRACT FROM AUTHOR]

Organic semiconductor-based photocatalysts have been alluring due to their edge over inorganic photocatalysts. In this study, a reusable copper-bismuth oxide/polyacrylonitrile (Cu–Bi 2 O 3 /PAN) fibrous mat was prepared by fast-process flame spray pyrolysis and electrospinning for photocatalytic degradation of methylene blue (MB) and rhodamine B (RhB) dyes. The results confirmed a well-defined morphology of Cu–Bi 2 O 3 /PAN fibers and good coordination of flame-made Cu–Bi 2 O 3 particles with the functional groups of PAN. The Cu–Bi 2 O 3 /PAN fibrous mat exhibits remarkable photocatalytic performance of 96.2% MB and 98.6% RhB degradation, with a reaction rate as high as about 4.5- and 10.2-times than that of flame-made Cu–Bi 2 O 3 particles and PAN under neutral condition, even after 10 cycles. The Cu–Bi 2 O 3 /PAN exhibits complete degradation of MB and RhB in 90 and 150 min under alkaline and slightly acidic conditions, respectively. The synergistic effect of Cu–Bi 2 O 3 and coordination bond between particles and functional groups of PAN promoted carrier migration, suppressed recombination of carriers and provided abundant radicals on the surface of the mat. Superoxide and hydroxyl radicals were the major active species involved in the degradation of RhB and MB, respectively. This work provides an insight into designing the Cu-metal-shuttle based photocatalysts to optimize fibrous mat application in water remediation. [Display omitted] • Facile synthesis of Cu–Bi 2 O 3 /PAN fibrous mat by flame spray pyrolysis and electrospinning. • Coordination bond in Cu–Bi 2 O 3 /PAN fibrous mat influenced electron transfer. • Cu–Bi 2 O 3 /PAN mat displays a higher reaction rate than flame-made particles. • Alkaline condition promotes photocatalytic degradation of methylene blue dye. • High reusability of Cu–Bi 2 O 3 /PAN in photodegradation of dyes after several cycles. [ABSTRACT FROM AUTHOR]

In this work, ultraviolet irradiation was employed to assist in the preparation of a novel photocatalyst composite in the form of carbon dots/zeolite-4A/TiO 2 , using coal tailings as the source of silicon-aluminum and carbon. The composite was designed for the degradation of methylene blue under 500 W of UV light irradiation. Zeolite-4A was used as a support for the well-dispersed carbon dots and TiO 2 nanoparticles. The as-prepared composites were subjected to thorough characterization, confirming the successful formation of zeolite-4A with a cube structure, along with the loading of TiO 2 and coal-based CDs in the composites. The experimental results demonstrated that the UV-CZTs nanocomposites exhibited a remarkable removal efficiency of 90.63% within 90 min for MB. The corresponding rate constant was exceptionally high at 0.0331 min−1, surpassing that of the Dark-CZTs and pure TiO 2. This significant enhancement was possibly due to the synergistic effect of adsorption photocatalysis of the UV-CZTs, combined with the excellent electron-accepting capabilities of the coal-based CDs, which led to highly improved charge separation. An investigation of the spent photocatalyst's recyclability revealed that it retained a remarkable 82.94% MB removal efficiency after five consecutive cycles, signifying the stability of the composite. Trapping experiments also elucidated the primary reactive species responsible for MB degradation, which were identified as photo-generated holes and ⸱O 2 − species. By this process, the hydroxyl radicals generated in the system successfully promoted the transformation of coal tailings to coal-based zeolite and coal-based CDs. Coal-based zeolite served as an excellent carrier of titanium dioxide, which improved its dispersibility. The inhibition of e−-h+ recombination of titanium dioxide by introducing coal-based CDs improved the photocatalytic ability of titanium dioxide. Through this study, coal tailings, as a coal processing waste, were transformed into high-value materials, and relevant photocatalytic composite materials could be prepared with broad application prospects. • A novel preparation method of the composite photocatalysts assisted with ultraviolet-irradiation were proposed. • UV-CDs/Zeolite-4A/TiO 2 composite photocatalysts were prepared using coal tailings as silicon-aluminum source and carbon source. • UV-CDs/Zeolite-4A/TiO 2 were the most stable and reusable because zeolite-4A confined TiO 2 on its surface. • The ternary structure of CDs-Zeolite-TiO 2 enhanced the photocatalytic performance of UV-CDs/Zeolite-4A/TiO 2. [ABSTRACT FROM AUTHOR]

Acetaminophen is a representative contaminant of emerging persistent organic pollutants that can cause environmental problems when it enters municipal wastewater. An innovative flower-like Z-scheme photocatalyst Bi–BiOI/UiO 66 heterojunction composite was designed and constructed via a one-step solvothermal method. Investigations demonstrated that the Z-scheme structure strongly contributes to increasing the degradation efficiency of micropollutants. The results indicate that the bandgap energy (E g) of the Bi–BiOI/UiO 66 composite decreases significantly from 3.22 eV to 2.43 eV, in comparison with that of pure copper-based UiO 66. Under suitable conditions (5 mg/L Ace, pH 3, 0.05 g/L), the organic pollutants in the water can be removed completely. A k value of 5.67 × 10−2 min−1 for the Bi–BiOI/UiO 66 heterojunction composite was found to effectively represent the acetaminophen photodegradation process. The reaction mechanism of acetamide in aqueous solution is also discussed. The Bi in Bi–BiOI can use surface plasmon resonance to form an electric field and accelerate the separation of photogenerated electrons and holes. This study highlights the potential of a novel photocatalyst for practical application. [Display omitted] • The UiO 66 particles grew in flower-like slits of Bi–BiOI surface. • The reduction in E g from 3.22 eV to 2.43 eV was obtained for Bi–BiOI/UiO-66 as compared to pure UiO 66. • The Ace in wastewater were completely removed and the structure of Bi–BiOI/UiO-66 was well reserved to recycle. [ABSTRACT FROM AUTHOR]

Photocatalytic degradation of organic pollution by biochar was a sustainable strategy for waste water remediation, nevertheless, it still suffers drawbacks like low efficiency due to the poor photocatalytic properties of pristine biochar. Herein, amino groups were grafted on the edge sites/defects of biochar by Friedel-Crafts acylation to enhance the degradation of high concentration dye solutions. The results suggested that the amino groups played an important role in imparting photocatalytic properties to biochar. Owing to the strong Lewis basicity and electron-donating ability of amino groups, their interaction with oxygen-containing functional groups/aromatic structures in biochar was improved, which enhanced the electron exchange ability of biochar under visible light irradiation, resulting in excellent degradation performances of high concentration RhB (∼10 times faster than ungrafted biochar). In this work, amino-grafted garlic peel biochar delivered a new idea for the future direction of biochar-based photocatalysis in wastewater remediation. [Display omitted] • Preparation of amino-grafted biochar by Friedel-Crafts acylation. • Amino groups were grafted on the edge sites/defects of biochar. • Amino groups form electron exchange system with different structures of biochar. • Biochar can effectively degrade high concentration RhB as a photocatalyst. [ABSTRACT FROM AUTHOR]

Cuprous oxide (Cu 2 O) nanoparticles (NPs) was anchored on wood by simple spraying method, then both soft and hard wood has been endowed efficient function photocatalytic degradation toward organic dyes and formaldehyde gas synergistically. The best recycle ability of wood based photocatalyst toward organic pollutants was achieved, which was characterized by photocatalytic degradation efficiency of methylene blue (MB) more than 95% after 100 cycles, and formaldehyde gas over 85% after 60 cycles. Cu 2 O NPs@wood performed much lower forbidden bandwidth (Eg), which accelerated to generate much more radical of e− and finally promoted the capacity of photocatalytic degradation. The proposed Cu 2 O NPs@wood catalysts has potential to be applied both in the field of wastewater and air pollution remediation. [Display omitted] • Cu 2 O NPs@wood photocatalytic degrade organic dyes & formaldehyde gas synergistically. • The best recycle ability of 100 & 60 cycles to MB & formaldehyde gas was achieved. • Facile spray coating technique offers practical and widespread applicability. [ABSTRACT FROM AUTHOR]

A novel octahedral distorted coordination complex was formed from a copper transition metal with a bidentate ligand (1,10-Phenanthroline) and characterized by Ultraviolet–visible spectroscopy, Ultraviolet–visible diffuse reflectance spectroscopy, Fourier-transform infrared spectroscopy, Brunauer-Emmett-Teller, Field emission scanning electron microscopy, and Single-crystal X-ray diffraction. The Hirshfeld surface and fingerprint plot analyses were conducted to determine the interactions between atoms in the Cu(II) complex. DFT calculations showed that the central copper ion and its coordinated atoms have an octahedral geometry. The Molecular electrostatic potential (MEP) map indicated that the copper (II) complex is an electrophilic compound that can interact with negatively charged macromolecules. The HOMO-LUMO analysis demonstrated the π nature charge transfer from acetate to phenanthroline. The band gap of [Cu(phen) 2 (OAc)]·PF 6 photocatalyst was estimated to be 2.88 eV, confirming that this complex is suitable for environmental remediation. The photocatalytic degradation of erythrosine, malachite green, methylene blue, and Eriochrome Black T as model organic pollutants using the prepared complex was investigated under visible light. The [Cu(phen) 2 (OAc)]·PF 6 photocatalyst exhibited degradation 94.7, 90.1, 82.7, and 74.3 % of malachite green, methylene blue, erythrosine, and Eriochrome Black T, respectively, under visible illumination within 70 min. The results from the Langmuir-Hinshelwood kinetic analysis demonstrated that the Cu(II) complex has a higher efficiency for the degradation of cationic pollutants than the anionic ones. This was attributed to surface charge attraction between photocatalyst and cationic dyes promoting removal efficiency. The reusability test indicated that the photocatalyst could be utilized in seven consecutive photocatalytic degradation cycles with an insignificant decrease in efficiency. [Display omitted] • The photocatalytic activity of copper (II) complex was evaluated for degradation of organic dyes. • Effective degradation of pollutants was achieved under excitation by visible-light. • Rod-like [Cu(phen) 2 (OAc)]·PF 6 complex shows excellent visible-light photocatalytic activity. • Rod-like [Cu(phen) 2 (OAc)]·PF 6 complex was analyzed by DFT method to predict reactive sites and band gap energy. [ABSTRACT FROM AUTHOR]

A simple inexpensive approach was used to synthesize NiFe-PANI nanocomposites and used for photodegradation of diclofenac sodium (DCF) in water sources. Morphological, optical, structural, and catalytic properties of the nanocomposites were investigated using X-ray diffraction (XRD) to confirm the cubic structure of NiFe nanoparticles and Fourier-transform infrared spectroscopy (FTIR) that revealed the presence of NiFe and PANI, scanning electron microscopy (SEM) showed the uniform distribution of NiFe nanoparticles onto the surface of PANI, Energy-Dispersive X-ray spectroscopy (EDX) was utilized to validate the composition of the obtained Permalloy NiFe-PANI nanocomposites, optical properties confirmed the decrease of E g band gap from 2.62 to 2.51 eV by the addition of NiFe. The NiFe-PANI composite showed superior photocatalytic efficiency in degrading DCF, achieving 82.53% degradation in 15 min and 97.89% in 60 min. This was significantly higher than the PANI alone, which achieved 62.72 and 93.48% degradation in the same time intervals respectively. The results indicated that the photocatalytic efficiency remained consistent, with no observable decrease, even after five cycles of recycling. The NiFe-PANI catalyst served as an efficient and cost-effective photocatalyst for DCF degradation, and the study holds promise for the photocatalytic removal of other organic pollutants from water and wastewater. [Display omitted] • PANI-NiFe nanocomposite synthesized via electro-deposition, combining conducting polymer and nanoparticles. • Enhanced catalytic properties from NiFe nanoparticles in PANI matrix. • Superior DCF degradation with NiFe-PANI nanocatalyst over pure PANI. • UV light boosts DCF degradation using NiFe-PANI nanocatalysts. [ABSTRACT FROM AUTHOR]

Magnesium oxides (MgO) have gained shown significant promise for a variety of applications, which can be modified by ions doping. In this study, bimetallic Ag-doped S–MgO nanoparticles were prepared by hydrothermal method and used for photocatalytic degradation of 4-chlorophenl (4-CP). EDX suggested the presence of no impurities, which mainly contained Mg, Ag, and S elements, suggesting that S and Ag were incorporated into the lattice of MgO as a result of successful doping. Estimated bandgap of Ag-doped S–MgO nanoparticles was 3.7 eV, lower than MgO (7.8 eV), but useful to improve optical characteristics and photocatalytic efficiency to degrade 4-CP up to a maximum of 99.60 ± 0.50%. The synergetic parameter during photocatalysis of 4-CP was 6.91, confirming the degradation of 4-CP. Quenching experiments proved the presence of hydroxyl radicals (•OH) and singlet dioxygen (1O 2) that were critical in 4-CP degradation. The kinetics rate constant was increased by 24.8% from 0.086 ± 0.004 to 0.108 ± 0.005 min−1 by the addition of sulfate in the reaction medium. The work proposes a new synthetic method for preparing catalysts that are capable of producing in-situ •OH radicals and 1O 2 to decompose the organic contaminants. [Display omitted] • Mesoporous bimetallic (Ag–S–Mg) nanoparticle was prepared via hydrothermal method. • Ag doping significantly reduced the bandgap of Ag-doped S–MgO nanoparticles. • Hydroxide radicals and singlet dioxygen were dominant species for 4-CP degradation. • Effect of matrix compositions on degradation efficiency was evaluated. • 4-CP degradation pathways by photocatalysis process were proposed. [ABSTRACT FROM AUTHOR]

Photocatalytic water decontamination has emerged as a highly promising technology for efficient and rapid water treatment, harnessing sustainable solar energy as its driving force. In this study, we prepared visible-light active Bi 2 S 3 /CoS 2 composites for the degradation of naproxen (NPX) and the inactivation of Escherichia coli (E. coli). The homogeneous dispersion of CoS 2 was stably integrated with Bi 2 S 3 , resulting in a significant enhancement of the specific surface area, efficient utilization of visible light, and effective separation of photogenerated charge carriers. Consequently, this synergistic photocatalytic system greatly facilitated the successful degradation of NPX and the inactivation of E. coli under visible-light irradiation. Compared to the pure Bi 2 S 3 and CoS 2 catalysts, the Bi 2 S 3 /CoS 2 (1:2) composites displayed significantly enhanced photodegradation activity, achieving 96.46% (k = 0.2847 min−1) degradation of NPX within 90 min and maintaining good recyclability with no significant decline after six successive cycles. Additionally, the photocatalytic inactivation of E. coli results indicated that Bi 2 S 3 /CoS 2 composites exhibited excellent performance, leading to the inactivation of 7 log 10 cfu mL−1 of bacterial cells after 150 min of visible-light exposure. Scanning Electron Microscopy (SEM) and K+ ions leakage tests demonstrated that the destruction of the E. coli cell membrane structure resulted in cell death. The outcomes of this work suggest that Bi 2 S 3 /CoS 2 composites hold significant potential for treating water contaminated with antibiotic and microbial pollutants. [Display omitted] • A novel bimetallic sulfide Bi 2 S 3 /CoS 2 composites was prepared using a simple reflux approach. • The incorporation of CoS 2 plays a crucial role in extracting photo-excited electrons from Bi 2 S 3 , leading to a high degree of carrier separation. • The Bi 2 S 3 /CoS 2 composites demonstrate exceptional performance in the degradation of naproxen and the inactivation of E. coli bacteria. • The possible degradation mechanism of naproxen and inactivation of E. coli were discussed. [ABSTRACT FROM AUTHOR]

Dissolved organic matter (DOM) is ubiquitous and widespread in natural water and influences the transformation and removal of antibiotics. Nevertheless, the influence of DOM molecular weight (MW) on the indirect photodegradation of antibiotics has rarely been reported. This study attempted to explore the influence of the molecular weight of DOM on the indirect photodegradation of two fluoroquinolone antibiotics (FQs), ofloxacin (OFL) and norfloxacin (NOR), by using UV–vis absorption and fluorescence spectroscopy. The results showed that indirect photodegradation was considered the main photodegradation pathway of FQs in DOM fractions. Triplet-state excited organic matter (3DOM*) and singlet oxygen (1O 2) were the main reactive intermediates (RIs) that affected the indirect photodegradation of FQs. The indirect photodegradation rate of FQs was significantly promoted in DOM fractions, especially in the low molecular weight DOM fractions (L-MW DOM, MW < 10 kDa). The results of excitation-emission matrix spectroscopy combined with parallel factor analysis (EEM-PARAFAC) showed that terrestrial humic-like substances had a higher humification degree and fluorophore content in L- MW DOM fractions, which could produce more 3DOM* and 1O 2 to promote the indirect photodegradation of FQs. This study provided new insight into the effects of DOM at the molecular weight level on the indirect photodegradation of antibiotics in natural water. [Display omitted] • The highest indirect photolysis rate was found in low molecular weight fractions. • 3DOM* and 1O 2 made more contribution to the FQs indirect photodegradation. • Terrestrial humic-like components contributed more to FQs indirect photolysis. • Low molecular weight DOM contained more terrestrial humic-like substances. [ABSTRACT FROM AUTHOR]

Wastewater containing antibiotics, organic dyes, and waterborne bacteria is a severe threat to human health and the environment. Amoxicillin has a slow metabolism rate in humans. Methylene blue is mutagenic and carcinogenic. In addition, Salmonella causes serious diarrhea. In this study, an effective 2D/2D photocatalyst with excellent elimination of these pollutants was fabricated by combining graphene oxide (GO), Bi 2 WO 6 , BiPO 4 and Ag species. GO was applied at varying loading contents (0.8, 1.6, 2.4, 3.2 wt%) to improve the properties of the photocatalyst toward the removal of representative pollutants. The chemical structures, morphology, light absorption and charge mobility were investigated by different GO loading samples. The results indicated that when the wt% of GO was 2.4%, the photocatalyst showed excellent photocatalytic properties and removal rates for typical pollutants. Amoxicillin and methylene blue were mineralized into CO 2 , H 2 O, and small molecules, while Salmonella was disinfected with excellent photocatalytic efficiency. Furthermore, the possible photodecomposition pathways of amoxicillin and methylene blue were proposed by DFT calculations and intermediates identified by LCMS. The mechanism of the photocatalytic process was investigated by radical trapping experiments, ESR spectroscopy, and Motty-Schottky plots. The free radicals could be produced constantly during the photocatalytic process, leading to mineralization of amoxicillin and methylene blue, and disinfection of Salmonella. In this work, a new perspective on GO modified Bi 2 WO 6 with different loading contents and the degradation pathways of antibiotics and dyes was proposed. [Display omitted] • Exceptional degradability by optimized GO doping photocatalyst was explored. • GO doping improved the activity by modifying light absorption and charge transfer. • The developed GO composite enabled the effective removal towards three pollutants. • The degradation pathways of AMX and MB were elicited by DFT calculations. • 100% mineralization rate is due to vulnerable atoms attacked by continuously generated ROS. [ABSTRACT FROM AUTHOR]

This work investigates the use of novel BiOI@ZIF-8 nanocomposite for the removal of acetaminophen (Ace) from synthetic wastewater. The samples were analyzed using FTIR, XRD, XPS, DRS, PL, FESEM-EDS, and ESR techniques. The effects of the loading capacity of ZIF-8 on the photocatalytic oxidation performance of bismuth oxyiodide (BiOI) were studied. The photocatalytic degradation of Ace was maximized by optimizing pH, reaction time and the amount of photocatalyst. On this basis, the removal mechanisms of the target pollutant by the nanocomposite and its photodegradation pathways were elucidated. Under optimized conditions of 1 g/L of composite, pH 6.8, and 4 h of reaction time, it was found that the BiOI@ZIF-8 (w / w = 1:0.01) nanocomposite exhibited the highest Ace removal (94%), as compared to that of other loading ratios at the same Ace concentration of 25 mg/L. Although this result was encouraging, the treated wastewater still did not satisfy the required statutory of 0.2 mg/L. It is suggested that the further biological processes need to be adopted to complement Ace removal in the samples. To sustain its economic viability for wastewater treatment, the spent composite still could be reused for consecutive five cycles with 82% of regeneration efficiency. Overall, this series of work shows that the nanocomposite was a promising photocatalyst for Ace removal from wastewater samples. • The highest acetaminophen removal by ZIF-8@BiOI photocatalyst was 94% • Optimum condition: 1 g/L of dose; 25 mg/L of Ace; pH 7; 4 h of reaction time • 1O 2 , ·OH and h + were photosensitizers responsible for acetaminophen removal • Spent ZIF-8@BiOI photocatalysts could be regenerated for five consecutive times [ABSTRACT FROM AUTHOR]

In this study, a number of leaching solutions (H 2 SO 4 , CuSO 4 and NaCl) and an electrochemical method were used together for the separation of Cu from waste printed circuit boards. Secondly, the magnetic-MOF(Cu) was synthesized using the Cu recovered from waste printed circuit boards. Thereafter, TiO 2 /mag-MOF(Cu) composite was prepared and its photocatalytic activity was assessed in the photo degradation of two prominent organophosphorus pesticides, namely malathion (MTN) and diazinon (DZN). The catalytic structure of the MOF-based composite was fully characterized by various analyses such as XRD, SEM, EDAX, FT-IR, VSM and UV–vis. The obtained analyses confirmed the successful synthesis of TiO 2 /mag-MOF(Cu) composite. The synthesized composite exhibited highly efficient in the degradation of both pollutants under the following conditions: pH 7, contaminant concentration 1 mg/L, the catalyst dosage of 0.4 g/L, visible light intensity 75 mW/cm2 and reaction time of 45 min. First order kinetic model was best suited with the experimental results (R2: 0.97–0.99 for different MTN and DZN concentrations). Trapping studies revealed that superoxide radicals (O 2 •−) played an important role during the degradation process. Furthermore, the catalyst demonstrated a superb recovery as well as high stability over five cyclic runs of reuse. In addition, the total organic carbon (TOC) analysis showed over 83% and 85% mineralization for MTN and DZN, respectively. The combined system of TiO 2 /mag-MOF(Cu)/Vis also exhibited a great level of efficiency and feasibility in the treatment of tap water and treated wastewater samples. It is concluded that TiO 2 /mag-MOF(Cu) could be used as an excellent catalyst for the photodegradation of MTN and DZN in aqueous solution. • An electrochemical method was applied to recover Cu from waste printed circuit boards. • TiO 2 /mag-MOF(Cu) nanocomposite was synthesized using the Cu obtained from the waste printed circuit boards. • TiO 2 /mag-MOF(Cu)/Vis system seems to be effective in malathion and diazinon degradation. • TiO 2 /mag-MOF(Cu) could keep its performance up to at least the 5th cycle. [ABSTRACT FROM AUTHOR]

Water contamination has compromised the quality of this resource during the last years with the presence of persistent organic pollutants. Because of the resistance of these compounds to degradation, several advance oxidation techniques have been proposed. In this study, we report the employment of an advance oxidation technique in the degradation of benzophenone-4 (BP-4), using TiO 2 as catalyst, which was obtained following a fast-hydrothermal method. TiO 2 nanowires (TiO 2 NWs) were fully characterized considering the morphology, elemental composition, oxidation states, vibrational modes and crystalline structure with SEM and TEM, EDS, XPS, FTIR and XRD, respectively. The photocatalytic degradation was carried out using a home-made photoreactor under slightly acidic conditions achieving an average of 90% removal. It was determined that the photocatalysis is the most probable route of degradation since the photolysis or catalysis procedures produce negligible contributions. An apparent kinetic constant of 1.29 × 10−2 min−1 was determined, according to a pseudo-first order reaction. Image 1 • TiO 2 nanowires with high surface area were synthesized using TiCl 4 as precursor. • TiO 2 nanowires photocatalytic performance was proved by photodegrading BP-4. • Optimal experimental conditions were defined for the BP-4 photocatalytic reactions. • A photocatalytic degradation of 90 ± 0.6% was obtained after 3 h of reaction. [ABSTRACT FROM AUTHOR]

In this research, zinc sulfide (ZnS) doped with manganese (Mn) is synthesized on functionalized multiwall carbon nanotubes (MWCNTs) nanocomposite by a facile co-precipitation method as the photocatalysis. Due to the excellent electrical and optical characteristics of ZnS:Mn/MWCNTs nanocomposite, it is worth to investigate its photodegradation activity. To investigate the photocatalytic degradation properties of organic pollutants, the synthesis conditions were optimized in the presence of four substances: COOH, ethylene glycol, sodium dodecyl sulfate, and polyvinyl-pyrrolidone. Surface studies of the photocatalyst, i.e., structural, morphological, optical and physical properties, were characterized by FTIR, PL, XRD, SEM, and TEM analyses. The results showed that Mn ions decreased the band gap energy of the nanocomposites and there was excellent adhesion between ZnS and MWCNTs in the synthesized composite. According to the results, MWCNTs effectively increased the photocatalytic activity of the ZnS nanoparticles by the electron-hole pair recombination of ZnS and MWCNTs, and the composites with the carboxylic functional group showed greater photocatalytic activity. In addition, the kinetic studies showed that the photocatalytic process obeyed the pseudo-first-order kinetic model. To determine the exact mathematical formula of the photocatalysis, response surface methodology was modeled by the central composite design method. Various parameters, such as the time of the treatment process and initial concentration of the pollutants were studied for a quadratic model that fit all the cases well and their mathematical models were obtained. • ZnS doped with Mn is synthesized on functionalized Multiwall Carbon Nanotube. • ZnS:Mn/MWCNTs shows spherical ZnS nanoparticles dispersed on MWCNTs surface. • MWCNTs increased ZnS photocatalytic activity by electron-hole pair recombination. • The photocatalytic process obeyed the pseudo-first-order kinetic model. • Response surface methodology was modeled by the central composite design method. [ABSTRACT FROM AUTHOR]

Developing a high-performance method that can effectively control pollution caused by low concentrations of antibiotics is urgently needed. Herein, a novel three-dimensional PPy/Zn 3 In 2 S 6 nanoflower composites were prepared for the comprehensive treatment of low-concentration tetracycline (Tc) hydrochloride in wastewater based on the adsorption/photocatalysis of Zn 3 In 2 S 6 and the conductivity of PPy. In this preparation method, adsorption enrichment and photocatalytic regeneration were conducted in two steps, eliminating the dilution and dispersion effects of aqueous solvents on photocatalytic species and antibiotics. Results showed that Zn 3 In 2 S 6 could effectively adsorb 87.85% of Tc at pH of 4.5 and photocatalytically degrade Tc at pH of 10.5. Although the adsorption capacity of Zn 3 In 2 S 6 was slightly reduced after being combined with PPy, its photocatalytic efficiency was substantially enhanced. Specifically, 0.5%PPy/Zn 3 In 2 S 6 could degrade 99.92% of the surface-enriched Tc in 1 h and induce the regeneration of the adsorption sites. Furthermore, the adsorption capacity remained above 85% even after recycling PPy/Zn 3 In 2 S 6 ten times. The photocatalytic degradation mechanism analysis revealed that the enrichment of Tc on 0.5%PPy/Zn 3 In 2 S 6 negatively impacts the photocatalytic efficiency, while • O 2 − and •OH radicals were the main oxidative species that played an important role in the photoregeneration process. [Display omitted] • 3D PPy/Zn 3 In 2 S 6 nanoflower composite was prepared for treatment of low-concentration Tc. • A two-step process of adsorption enrichment and photocatalytic regeneration was proposed. • Proposed method can eliminate the dilution and dispersion effects of solution on Tc. • 3D PPy/Zn 3 In 2 S 6 nanoflowers can be used many times and maintain their treatment efficiency. [ABSTRACT FROM AUTHOR]

Organic pollutants are the most critical threats to the health of air and water resources. On this basis, fabricating a photocatalytic acrylic film with dual-use (i.e. removing benzene from air and MB/MO dyes from water) was aimed in this research. For this purpose, waste warm filter cake (WWFC) was used to extract zinc from it. Zinc element was separated from WWFC by a basic leaching method and acidified to prepare zinc oxide nanoparticles. In the following, a simple hydrothermal method was used to increase the surface functionality of the extracted ZnO nanoparticles in order to establish active reaction sites for reaction to silane coupling agent and increase in the holes that were prepared during photo-excitation. Thereafter, the nanoparticles were modified with 3-glycidoxypropyltriethoxysilane (GPTES) at different concentrations. The band gap of the modified nanoparticles decreased from 3.25 to 3.1 eV by surface modification. The photocatalytic performance of ZnO nanoparticles was assessed by degradation of MB and MO aqueous solution (50 ppm) under simulated UV/Visible irradiations. MB and MO were degraded 91 and 60% under UV light and 65 and 50% under visible light after 150 min of irradiation. The photo degradation rate increased after adding carboxy methyl cellulose (CMC) surfactant to methylene blue and adding cocamide-dea (CDE-G) surfactant to methyl orange. The results confirmed that the green surfactants improve the dispersion and surface interaction of the modified nanoparticles in the dyes solution and cause more electron charge transfer which creates effective photocatalytic sites. The prepared nanocomposite films were placed in a photo-reactor to remove gaseous benzene from air under UV/visible irradiation. Gas chromatography (GC) results showed that the modified nanoparticles removed up to 35.25 and 20.34% of benzene from air. Colorimetric analysis (ΔE*) showed that the acrylic film contained modified nanoparticles degraded 91 and 82% of MB, and 85 and 76% of MO under UV/visible lights, respectively. In the end, it can be said that these photocatalytic films are able to remove environmental pollution in air and water. [Display omitted] • Successful use of waste warm filter cake to extract zinc and prepare zinc oxide nanoparticles. • A decorative paint for indoor applications with capability of benzene and dyes removal was fabricated. • Photocatalytic films were prepared using water based acrylic latex and ZnO photocatalyst. • ZnO nanoparticles were surface-modified using epoxy silane to prepare core-shell. • Films contained core-shells were used for photocatalysis of Benzene/dyes under UV/visible lights. [ABSTRACT FROM AUTHOR]

Recently, new methods of utilizing chemistry materials to overcome environmental issues worldwide, for instance, water purification have widely evolved since it is well-aligned with the sustainable development goals 6: clean water and sanitation. These issues have become a vital research topic for researchers in the last decade, particularly, the use of green photocatalyst due to the limitation of renewable resources. Herein, we report the modification of titanium dioxide with yttrium manganite (TiO 2 /YMnO 3) by a novel high-speed stirring technique in n-hexane-water utilizing Annona muricata L. leaf extracts (AMLE). The YMnO 3 incorporation in the presence of TiO 2 was introduced to accelerate the photocatalytic performance for the degradation of malachite green in aqueous media. TiO 2 modification with YMnO 3 presented a drastic decline of bandgap energy from 3.34 to 2.38 eV and the highest rate constant (k app) of 2.275 × 10-2 min-1. Surprisingly, TiO 2 /YMnO 3 exhibited an extraordinary photodegradation efficiency of 95.34%, which was 1.9-fold higher than that of TiO 2 under visible light illumination. The enhanced photocatalytic activity is ascribed to the formation of a TiO 2 /YMnO 3 heterojunction, narrower optical band gap, excellent charge carrier separation. H+ and . O2– were the major scavenger species that play a significant role in the photodegradation of malachite green. Additionally, TiO 2 /YMnO 3 shows outstanding stability over five cycles of photocatalytic reaction without significant loss of its effectiveness. This work presents a recent understanding of the green construction of a novel TiO 2 -based YMnO 3 photocatalyst with excellent efficiency in the visible region for environmental technology application in water purification specifically in degrading organic dyes. [Display omitted] • TiO 2 was modified with YMnO 3 by the highspeed stirring method. • YMnO 3 incorporation accelerated the photocatalytic activity of TiO 2. • The degradation percentage of malachite green achieved 95.34% within 120 min. • TiO 2 /YMnO 3 exhibits outstanding stability after five successive photocatalytic cycles. [ABSTRACT FROM AUTHOR]

Traditional membranes are inefficient in treating highly toxic organic pollutants and oily wastewater in harsh environments, which is difficult to meet the growing demand for green development. Herein, the Co(OH) 2 @stearic acid nanocellulose-based membrane was prepared by depositing Co(OH) 2 on the nanocellulose-based membrane (NBM) through chemical soaking method, which enables efficient oil/water mixtures separation and degradation of pollutants by photocatalysis in harsh environments. The Co(OH) 2 @stearic acid nanocellulose-based membrane (Co(OH) 2 @stearic acid NBM) shows good photocatalytic degradation performance for methylene blue pollutants in harsh environment, and has significant degradation rate (93.66%). At the same time, the Co(OH) 2 @stearic acid NBM with superhydrophobicity and superoleophilicity also exhibits respectable oil/water mixtures separation performance (n-Hexane, dimethyl carbonate, chloroform and toluene) under harsh environment (strong acid/strong alkali), which has an excellent oil-water mixtures separation flux of 87 L·m−2·h−1 (n-Hexane/water) and oil-water mixture separation efficiency of over 93% (n-Hexane/water). In addition, this robust Co(OH) 2 @stearic acid NBM shows good self-cleaning and recycling performance. Even though seven oil-water separation tests have been carried out under harsh environment, it can still maintain respectable oil-water mixture separation rate and flux. The multifunctional membrane has excellent resistance to harsh environments, oil-water separation and pollutant degradation can be performed even in harsh environments, which provides a convenient way to treat sewage under harsh conditions efficiently and has great potential in practical application. • The multifunction nanocellulose-based membrane was prepared. • The membrane showed good oil/water separation ability in strong acid/alkali environment. • This membrane showed great photocatalytic degradation activity. [ABSTRACT FROM AUTHOR]

The incessant accumulation of pharmaceutically active compounds (PhACs) in various environmental compartments represents a global menace. Herein, an equimolar high entropy alloy (HEA), i.e., FeCoNiCuZn, is synthesized via a facile and scalable method, and its effectiveness in eliminating four different PhACs from aqueous matrices is rigorously examined. Attributing to its relatively low bandgap and multielement active sites, the as-synthesized quinary HEA demonstrates more pronounced photocatalytic decomposition efficiency, towards tetracycline (86%), sulfamethoxazole (94%), ibuprofen (80%), and diclofenac (99%), than conventional semiconductor-based photocatalysts, under visible light irradiation. Additionally, radical trapping assays are conducted, and the dissociation intermediates are identified, to probe the plausible photocatalytic degradation pathways. Further, the end-products of FeCoNiCuZn-mediated photocatalysis are apparently non-toxic, and the HEA can be successfully recycled repeatedly, with no obvious leaching of heavy metal ions. Overall, the findings of this study testify the applicability of FeCoNiCuZn as a visible light-active photocatalyst, for treating wastewaters contaminated with PhACs. [Display omitted] • An equimolar FeCoNiCuZn high entropy alloy (HEA) is synthesized by induction melting. • The quinary HEA can effectively degrade pharmaceutical residues under visible light. • The plausible photocatalytic degradation mechanism is investigated and proposed. • The photocatalysis end-products do not present any imminent threat to human health. • The HEA exhibits extraordinary stability for repeated usage. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA), a water-soluble synthetic polymer, is one of the most prevalent non-native polyvinyl alcohols found in the environment. Due to its inherent invisibility, its potential for causing severe environmental pollution is often underestimated. To achieve efficient degradation of PVA in wastewater, a Cu 2 O@TiO 2 composite was synthesized through the modification of titanium dioxide with cuprous oxide, and its photocatalytic degradation of PVA was investigated. The Cu 2 O@TiO 2 composite, supported by titanium dioxide, facilitated photocarrier separation and demonstrated high photocatalytic efficiency. Under alkaline conditions, the composite exhibited a 98% degradation efficiency for PVA solutions and a 58.7% PVA mineralization efficiency. Radical capture experiments and electron paramagnetic resonance (EPR) analyses revealed that superoxide radicals primarily drive the degradation process within the reaction system. Throughout the degradation process, PVA macromolecules are broken down into smaller molecules, including ethanol, and compounds containing aldehyde, ketone, and carboxylic acid functional groups. Although the intermediate products exhibit reduced toxicity compared to PVA, they still pose certain toxic hazards. Consequently, further research is necessary to minimize the environmental impact of these degradation products. [Display omitted] • Visible photocatalytic degradation system achieves high degradation and mineralization rate of PVA. • Superoxide radicals play an important role in the degradation of PVA. • A possible degradation pathway for visible photocatalytic degradation of PVA were proposed. • Although the intermediate products are less toxic, there are still some toxic hazards. [ABSTRACT FROM AUTHOR]

Abstract β-cyclocitral and β-ionone are ones of major algal odorants produced by oxidation of the β-carotene that exists in algae cells. These compounds degraded the quality of drinking water therefore it needed to be treated in drinking water treatment by advanced oxidation processes. In this study, UV photolysis and UV-chlorination reactions along with chlorination to remove these odorants in water were compared. Kinetics of three reactions were well fitted at pseudo-first order model. Among three reactions, UV-chlorination was the most effective due to generation of OH and Cl radicals. β-ionone showed faster degradation compared to β-cyclocitral due to the existence of double bond in the alkyl carbon chain. In addition, radical contributions of degradation of odorants were examined. During UV-chlorination, UV photolysis contributed around 50% of removal for two odorants. OH radical took part of 36% removal of β-ionone and 50% removal of β-cyclocitral. Unlike β-ionone, β-cyclocitral was not degraded by reactive chlorine species during UV-chlorination. Acidic pH was favorable for UV-chlorination due to different quantum yield and radical scavenging effect by chlorine species. Formation of trace amount of chloroform was observed during UV-chlorination. The methyl ketone group of β-ionone was the main site for chloroform production. Several byproducts during UV photolysis and UV-chlorination of β-ionone were identified by GC-MS, and these were degraded with further reaction by UV-induced isomerization, OH radical, and bond scission mechanisms. β-cyclocitral was formed as byproducts during UV-chlorination of β-ionone. Based on degradation byproducts, the degradation pathways of β-ionone and β-cyclocitral of UV photolysis and UV-chlorination were suggested based on the identified byproducts. This study showed UV-chlorination process can be applied for degrading odorants like β-cyclocitral and β-ionone. Graphical abstract Image 1 Highlights • The removals of two odorants during UV photolysis and UV-chlorination was examined. • Acidic pH was favorable for UV-chlorination of β-cyclocitral and β-ionone. • UV-chlorination of odorant was achieved by UV photolysis, OH and Cl radicals. • Degradation pathways of β-cyclocitral and β-ionone during reactions were proposed. • UV-chlorination can be an option for treating algal odorant in water treatment plants. [ABSTRACT FROM AUTHOR]

Abstract In the present work, one-step green synthesis of WO 3 based on the interaction of ammonium paratungstate and Spondias mombin leaves extract is reported. Different concentrations of iodine and phosphorus in the range of (2%, 5% and 10%) were firstly incorporated into the prepared WO 3 nanoparticles to obtain Iodine doped and Phosphorus doped WO 3 nanoparticles respectively. Subsequently, iodine and phosphorus co-doped WO 3 nanocomposites was prepared using a wet impregnation method followed by calcination at high temperature. The nanomaterials were characterized by HRSEM, HRTEM, BET, UV–Visible, EDS, XRD and XPS. The photo-oxidation of dyeing wastewater by the synthesized WO 3 nanomaterials were tested and assessed using Total organic carbon (TOC) and Chemical oxygen demand (COD) as indicator parameters. XRD and HRSEM analysis demonstrated the formation of only monoclinic phase of WO 3 irrespective of the dopants. The UV–Visible diffuse reflectance spectroscopy showed the band gap energy of 2.61 eV for undoped WO 3 and 2.02 eV for I-P co-doped WO 3 nanocomposites. The surface area of I-P co-doped WO 3 (416.18 m2/g) was higher than the undoped WO 3 (352.49 m2/g). The XPS demonstrated interstitial and substitution of oxygen (O2−) vacancies in WO 3 by I− and P3+ and formed I-P-WO(3-x). The I-P co-doped WO 3 exhibited higher catalytic activities (93.4% TOC, 95.1% COD) than the undoped (54.9% TOC, 79.2% COD) due to the synergistic effects between the two dopants. The experimental data better fitted to pseudo-second order than first order and pseudo-first order model. This study demonstrated the enhanced photocatalytic performance of I-P co-doped WO 3 nanocomposites under sunlight. Highlights • Green synthesis of WO 3 nanoparticles using Spondias mombin aqueous leaves extract. • Mono and co-doping of WO 3 nanoparticles by Iodine and Phosphorus. • Characterization of the nanomaterials and estimation of band gap energy of I-P co-doped WO 3 nanocomposites. • Photocatalytic degradation of Local dyeing wastewater by the prepared nanomaterials under sunlight irradiation. [ABSTRACT FROM AUTHOR]

Abstract LaFeO 3 (LFO)-doped acid-modified natural zeolites were prepared by an impregnation-calcination method for the first time. Their effectiveness as photo-Fenton catalysts was evaluated using decolorization of Rhodamine B (RhB) as an organic model. The sample 1HNZ-30LFO was synthesized by using the support of 1HNZ, which was produced via the acid (1 N HCl) treatment of natural zeolite (NZ) at 80 °C for 3 h. It was consisting of approximately 30 wt% LFO and exhibited a higher removal rate of RhB, especially photocatalytic performance, than the pure LFO and parent 1HNZ. This was attributed to the synergistic effect of good adsorption ability of modified zeolite host and a large number of active sites provided by LFO guest for photo-Fenton reaction. Various operational parameters including catalyst dosage, H 2 O 2 concentration, solution pH and dye concentration were examined in the photo-Fenton catalytic degradation of RhB. 98.3% of RhB was degraded under the conditions of 0.8 g L−1 1HNZ-30LFO, 10 mg L−1 RhB, 10 mM H 2 O 2 and initial pH of 6. The catalytic activity of 1HNZ-30LFO was largely retained after 4 cycles of use and recycle; suggesting it could be a promising heterogeneous photocatalyst for dye degradation in wastewater via the photo-Fenton process. Highlights • LaFeO 3 -doped acid-modified natural zeolite was studied for photo-Fenton. • It had improved organic adsorption, facilitating photo-Fenton degradation. • It was much more effective in degrading organic compared to bulk LaFeO 3. • Its use was optimized at solution pH, H 2 O 2 /dye concentration and catalyst dosage. • The good stability and reusability suggested its potential for practical use. [ABSTRACT FROM AUTHOR]

Abstract Herein, Kiwi peel activated carbon (AC), Materials Institute Lavoisier (MIL-88B (Fe), and AC/MIL-88B (Fe) composite were synthesized and used as catalysts to degrade Reactive Red 198. The material properties were analyzed by the FTIR, BET-BJH, XRD, FESEM, EDX, TGA, and UV–Vis/DRS. The BET surface area of AC, MIL-88B (Fe) and AC/MIL-88B (Fe) was 1113.3, 150.7, and 199.4 m2/g, respectively. The band gap values (E g) estimated by Tauc plot method, were obtained 5.06, 4.19 and 3.79 eV for AC, MIL-88B (Fe) and AC/MIL-88B (Fe), respectively. The results indicated that the AC/MIL-88B (Fe) composite had higher photocatalytic activity (99%) than that of pure AC (79%) and MIL-88B (Fe) catalysts (87%). The decolorization kinetic was matched well with the second-order model. Moreover, the data were modeled using least squares support vector machine which optimized with Cuckoo optimization algorithm. The optimal parameters were found 0.837 and 3.49e+02 based on σ2 and γ values, respectively. The mean square error (MSE) and correlation coefficient (R2) values were obtained 3.97 and 0.948. Therefore, the attained data, materials characterization and prediction of modeling validate the composite form of MIL-88B(Fe) with new AC, had better photocatalytic activity in comparison with the individual form. Graphical abstract Image 1 Highlights • Activated carbon/metal-organic framework nanocomposite photocatalyst was prepared. • Dye degradation mathematical modeling from wastewater was done. • Surface area of AC, MIL-88B and AC/MIL-88B was 1113.3, 150.7, and 199.4 m2/g. • The photocatalytic decolorization kinetics followed the second-order kinetic model. • Least squares support vector machine with Cuckoo algorithm modeled dye degradation. [ABSTRACT FROM AUTHOR]

Abstract A simple and clean synthesis for Nd 2 Sn 2 O 7 -SnO 2 nanocomposites as high-efficiency visible-light responsive photocatalyst is described applying extract of pineapple, for the first time. As novel and non-toxic biofuel, extract of pineapple, is employed to fabricate Nd 2 Sn 2 O 7 -SnO 2 nanocomposites through an environment-friendly procedure. The findings denote that the applied biofuel can play a meaningful role as capping agent during preparation of Nd 2 Sn 2 O 7 -SnO 2 nanocomposites. Depending on the applied dosage of pineapple extract as well as time for fabrication, the grain size, photocatalytic yield and morphology of Nd 2 Sn 2 O 7 -SnO 2 structures changed. A suite of identification methods like XRD, TEM, EDS, DRS, BET and FESEM are utilized for investigation of the produced Nd 2 Sn 2 O 7 -SnO 2 nanocomposites. Nd 2 Sn 2 O 7 -SnO 2 structures are utilized as visible-light responsive photocatalyst to degrade the rhodamine B and eosin Y contaminants. The produced Nd 2 Sn 2 O 7 -SnO 2 nanocomposites have been found to be very effective as visible-light responsive photocatalyst to degrade contaminants which may bring to environmental pollution. Graphical abstract Image 1 Highlights • A simple and clean synthesis for Nd 2 Sn 2 O 7 -SnO 2 nanostructures as high-efficiency visible-light photocatalyst. • Usage of extract of pineapple as novel and non-toxic biofuel. • Investigation of the effect of the dosage of pineapple extract on size, morphology and photocatalytic yield. • Nd 2 Sn 2 O 7 -SnO 2 nanostructures exhibit superior visible-light photocatalytic activity. [ABSTRACT FROM AUTHOR]

Abstract In this study, degradation of a pharmaceutical drug, Phenazone (PNZ) has been carried out via heterogeneous photocatalysis, photo-Fenton and in-situ dual process (photocatalysis + photo-Fenton) in suspension and fixed-mode under artificial UV-A as well as under natural solar radiations. Waste material such as foundry sand (FS) was exploited as a supplement for iron in case of photo-Fenton reaction. The distinct processes including photocatalysis and photo-Fenton were found to be competent for the degradation of PNZ as both processes revealed an almost 90–95% removal of PNZ after 180 min of UV irradiations. The degradation was improved to a great extent with remarkable reduction in treatment time of PNZ to almost 105 min when these two individual processes were combined together within the same unit. An almost 14% synergy of dual process over distinct processes was obtained. For fixed-bed studies, TiO 2 immobilized hollow circular composite disc already containing FS was utilized which yielded an almost 96% reduction in the concentration of PNZ after 4 h of solar irradiations. The disc was recycled 10 times and its stability and activity was confirmed through XRD, SEM/EDS, and DRS. The mineralization of PNZ was confirmed through significant reduction in COD and generation of anions during the treatment process. The transformation products were examined through GC-MS analysis. The novel technique of in-situ dual process especially in fixed-mode visualized in this study by employing renewable energy and durable catalyst can represent a viable solution to various industries for the treatment of wastewater comprising of bio-recalcitrant pollutants. Graphical abstract Image 1 Highlights • An economically viable process has been studied for the treatment of wastewater. • Waste foundry sand was used as an iron source. • Synergistic results over discrete processes were obtained through dual process. • Treatment time of phenazone was significantly reduced via dual process. • Fe-TiO 2 composite disc was recycled 10 times. [ABSTRACT FROM AUTHOR]

Abstract Rational designing of metal-free carbon nitride based photocatalysts can lead to an excellent optical response and a higher photocatalytic activity driven by visible and solar light. This combines green photocatalytic technology with greener materials prepared by facile approaches for environmental remediation. Herein we report utilization of star photocatalyst g-C 3 N 4 (CN) to form highly efficient hetero-assemblies along with acidified g-C 3 N 4 (ACN), polyaniline (PANI), reduced graphene oxide (RGO) and biochar. By use of these organic semiconductors we synthesize g-C 3 N 4 /ACN/RGO@Biochar (GARB), g-C 3 N 4 /PANI/RGO@Biochar (GPRB) and ACN/PANI/RGO@Biochar (APRB) nano-assemblies with different optical response and band edge positions for a better charge flow and reduced recombination of carriers. These synthesized catalysts were used for visible light powered degradation of 2,4-Dichlorophenoxy acetic acid (2,4-D) and ibuprofen (IBN). APRB performs the best and degrades 99.7% and 98.4% of 2,4-D and IBN (20 mg L−1) under Xe lamp exposure in 50 min and retention of high activity in natural sunlight. Optical analysis, photoelectrochemical response and radical quenching studies show both hydroxyl and superoxide radical anions as major reactive species and a Z-scheme photocatalytic mechanism. RGO acts as an electron mediator and protects higher positioned bands of PANI and ACN in APRB for a remarkable photocatalytic activity for a metal free material. The degradation pathway was analyzed by LC-MS analysis and 42% and 40% total organic carbon was removed in 2 h for 2,4-D and IBN degradation respectively. The toxicity of degraded products was analyzed by analyzing viability of human peripheral blood cells with retaining of 99.1% cells. Graphical abstract Image 1 Highlights • Metal free organic semiconductors based nano-assemblies as photocatalysts. • Utilizing g-C 3 N 4 , acidified C 3 N 4 , PANI for designing efficient photocatalyst. • Z-scheme mechanism-high spectral response and charge separation. • Excellent photo-degradation of Ibuprofen and 2,4-D under artificial and solar light. • Complete mineralization and no toxicity on human PBL cells. [ABSTRACT FROM AUTHOR]

Abstract Antibiotics discharged to the environment constitute a main concern for which different treatment alternatives are being studied, some of them based on antibiotics removal or inactivation using by-products with adsorbent capacity, or which can act as catalyst for photo-degradation. But a preliminary step is to determine the general characteristics and magnitude of the degradation process effectively acting on antibiotics. A specific case is that of sulfonamides (SAs), one of the antibiotic groups most widely used in veterinary medicine, and which are considered the most mobile antibiotics, causing that they are frequently detected in both surface- and ground-waters, facilitating their entry in the food chain and causing public health hazards. In this work we investigated abiotic and biotic degradation of three sulfonamides (sulfadiazine –SDZ-, sulfachloropyridazine –SCP-, and sulfamethazine –SMT-) in aqueous media. The results indicated that, in filtered milliQ water and under simulated sunlight, the degradation sequence was: SCP > SDZ ≈ SMT. Furthermore, the rate of degradation clearly increased with the raise of pH: at pH 4.0, half-lives were 1.2, 70.5 and 84.4 h for SCP, SDZ and SMT, respectively, while at pH 7.2 they were 2.3, 9.4 and 13.2 h for SCP, SMT and SDZ. The addition of a culture medium hardly caused any change in degradation rates as compared to experiments performed in milliQ water at the same pH value (7.2), suggesting that in this case sulfonamides degradation rate was not affected by the presence of some chemical elements and compounds, such as sodium, chloride and phosphate. However, the addition of bacterial suspensions extracted from a soil and from poultry manure increased the rate of degradation of these antibiotics. This increase in degradation cannot be attributed to biodegradation, since there was no degradation in the dark during the time of the experiment (72 h). This indicates that photo-degradation constitutes the main removal mechanism for SAs in aqueous media, a mechanism that in this case was favored by humic acids supplied with the extracts from soil and manure. The overall results could contribute to the understanding of the environmental fate of the three sulfonamides studied, aiding to program actions that could favor their inactivation, which is especially relevant since its dissemination can involve serious environmental and public health risks. Highlights • Photo-degradation was the main degradation process for the three sulfonamides studied. • Increased pH favored degradation under simulated sunlight in filtered milliQ water. • Soil and poultry manure extracts (bacterial suspensions) further increased photo-degradation. [ABSTRACT FROM AUTHOR]

Abstract Fibrous silica–titania (FST) catalysts were synthesized by microemulsion followed by silica seed-crystal crystallization methods under various molar ratios of toluene to water (T/W). The catalysts were characterized by XRD, UV-DRS, FESEM, TEM, AFM, N 2 adsorption–desorption, FTIR, and ESR. The results revealed that altering the T/W ratio affected the growth of the silica and titania and led to different size, fiber density, silica–titania structure, and number of hydroxyl groups, as well as oxygen vacancies in the FSTs, which altered their behavior toward subsequent application. Photodegradation of ibuprofen (IBP) are in the following order: FST(6:1) (90%) > FST(5:1) (84%) > FST(7:1) (79%) > commercial TiO 2 (67%). A kinetics study using Langmuir–Hinshelwood model illustrated that the photodegradation followed the pseudo-first-order and adsorption was the rate-limiting step. Optimization by response surface methodology (RSM) showed that the pH, initial concentration, and catalyst dosage were the remarkable parameters in photodegradation of IBP. The FST (6:1) maintained its photocatalytic activities for up to five cycles reaction without serious catalyst deactivation, and was also able to degrade other endocrine-disrupting chemicals, indicating its potential use for the treatment of those chemicals in wastewater. Graphical abstract Image 1 Highlights • Efficient urchin-like fibrous SiO 2 –TiO 2 (FST) photocatalysts were well synthesized. • Fiber density was altered by varying the molar composition of toluene and water. • FST(6/1) catalyst gave the highest photodegradation (90%) of ibuprofen. • Alternate integration of SiO 2 –TiO 2 dendrimeric fibers enhanced photodegradation. • FST showed a good potential as a visible-light-driven photocatalyst for many EDCs. [ABSTRACT FROM AUTHOR]

The present study was done to investigate and compare the photocatalytic and antibacterial activity of two in situ Manganese doped ternary nanocomposites. The dual ternary hybrid systems comprised Mn-doped Ag 2 WO 4 coupled with MoS 2 -GO and Mn-doped MoS 2 coupled with Ag 2 WO 4 -GO. Both hierarchical alternate Mn-doped ternary heterojunctions formed efficient plasmonic catalysts for wastewater treatment. The novel nanocomposites were well-characterized using XRD, FTIR, SEM-EDS, HR-TEM, XPS, UV-VIS DRS, and PL techniques confirming the successful insertion of Mn+2 ions in respective host substrates. The bandgap of the ternary nanocomposites evaluated by the tauc plot showed them visible light-active nanocomposites. The photocatalytic ability of both Mn-doped coupled nanocomposites was investigated against the dye methylene blue. Both ternary nanocomposites showed excellent sunlight harvesting ability for dye degradation in 60 min. The maximum catalytic efficiency of both photocatalysts was obtained at a solution pH value of 8, photocatalyst dose and oxidant dose of 30 mg/100 mL and 1 mM for Mn–Ag 2 WO 4 /MoS 2 -GO, 50 mg/100 mL, 3 mM for Mn–MoS 2 /Ag 2 WO 4 -GO keeping IDC of 10 ppm for all photocatalysts. The nanocomposites showed excellent photocatalytic stability after five successive cycles. The response surface methodology was used as a statistical tool for the evaluation of the photocatalytic response of several interacting parameters for dye degradation by ternary composites. The antibacterial activity was determined by the inactivation of gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria by support-based doped ternary hybrids. [Display omitted] • Alternate Mn-doped ternary heterostructures supported over graphene oxide were prepared hydrothermally. • Mn-doped ternary heterostructures (Mn-M/ AG and Mn-A/ MG) showed 95% and 99% dye degradation. • The effect of alternate Mn doping and synergistic effect of all components of a ternary system was studied. • The antibacterial activity of hybrids was determined against gram-negative (Escherichia coli) and gram-positive (Staphylococcus aureus) bacteria. [ABSTRACT FROM AUTHOR]

Owing to its feasibility, efficiency in light-harvesting and effectiveness in the interfacial charge transfer between two n-type semiconductors, constructing heterojunction photocatalysts have been identified as an effective way for enhancing the photocatalytic properties. In this research, a C–O bridged CeO 2 /g-C 3 N 4 (cCN) Step-scheme (S-scheme) heterojunction photocatalyst was constructed successfully. Under visible light irradiation, the cCN heterojunction exhibited the photocatalytic degradation efficiency of methyl orange, which was about 4.5 and 1.5 times higher than that of pristine CeO 2 and CN, respectively. The DFT calculations, XPS and FTIR analyses demonstrated the formation of C–O linkages. And the calculations of work functions revealed the electrons would flow from g-C 3 N 4 to CeO 2 due to the difference in Fermi levels, resulting in the production of internal electric fields. Benefiting from the C–O bond and internal electric field, the photo-induced holes in the valence band of g-C 3 N 4 and the photo-induced electrons from conduction band of CeO 2 would be recombined when exposed to visible light irradiation, while leaving the electrons with higher redox potential in the conduction band of g-C 3 N 4. This collaboration accelerated the separation and transfer rate of photo-generated electron-hole pairs, which promoted the generation of superoxide radical (•O 2 −) and improved the photocatalytic activity. • Formed C–O bond acted as a charge pathway and facilitated the transfer of charge. • S-scheme heterojunction together with C–O bond boosted photocatalytic activity. • Mechanism of charge transfer and separation in heterojunction was clarified. • The main active specie was the.•O 2 − in the photocatalytic process. [ABSTRACT FROM AUTHOR]

This study aims to fabricate a novel integrated photocatalytic adsorbent (IPA) via a green solvothermal process employing tea (Camellia sinensis var. assamica) leaf extract as a stabilizing and capping agent for the removal of organic pollutants from wastewater. An n-type semiconductor photocatalyst, SnS 2, was chosen as a photocatalyst due to its remarkable photocatalytic activity supported over areca nut (Areca catechu) biochar for the adsorption of pollutants. The adsorption and photocatalytic properties of fabricated IPA were examined by taking amoxicillin (AM) and congo red (CR) as two emerging pollutants found in wastewater. Investigating synergistic adsorption and photocatalytic properties under varying reaction conditions mimicking actual wastewater conditions marks the novelty of the present research. The support of biochar for the SnS 2 thin films induced a reduction in charge recombination rate, which enhanced the photocatalytic activity of the material. The adsorption data were in accordance with the Langmuir nonlinear isotherm model, indicating monolayer chemosorption with the pseudo-second-order rate kinetics. The photodegradation process follows pseudo-first-order kinetics with the highest rate constant of 0.0450 min−1 for AM and 0.0454 min−1 for CR. The overall removal efficiency of 93.72 ± 1.19% and 98.43 ± 1.53% could be achieved within 90 min for AM and CR via simultaneous adsorption and photodegradation model. A plausible mechanism of synergistic adsorption and photodegradation of pollutants is also presented. The effect of pH, Humic acid (HA) concentration, inorganic salts and water matrices have also been included.The photodegradation activity of SnS 2 under visible light coupled with the adsorption capability of the biochar results in the excellent removal of the contaminants from the liquid phase. [Display omitted] • An integrated photocatalytic adsorbent was prepared from SnS 2 thin film and biochar. • SnS 2 thin films of larger size have been grown over biochar surface. • A green synthesis route has been employed for the fabrication of IPA. • The prepared IPA showed enhanced removal of amoxicillin and congo red. • Overall removal efficiency >90% could be achieved within 90 min. [ABSTRACT FROM AUTHOR]

As an environmentally benign disinfection strategy, photocatalytic bacterial inactivation using nanoparticles involves photogenerated reactive species that cause cellular oxidative stress. Rationalising the structural performance of photocatalysts for the practical uses such as wastewater treatment has attracted significant attention; however, the contribution of reactive species to their photocatalytic antibacterial activities at the molecular and transcriptomic levels remains unclear. In this study, nontoxic bismuth oxychloride (BiOCl) photocatalysts with different nanoscale thicknesses, including nanosheets (Ns, ∼5.4 nm), nanoplates (Np, ∼1.8 nm), and ultra-nanosheets (Uns, ∼1.1 nm), were synthesised under hydrothermal conditions. Among the three samples, BiOCl Uns exhibited the most effective photocatalytic degradation efficiency with the calculated apparent rate constant of 0.0294 min−1, ∼4 times faster than that of Ns, whereas BiOCl Ns possessed the most pronounced bactericidal effect (5.4 log inactivation). Such findings indicate the distinct role of the photoactive species responsible for photocatalytic bacterial inactivation. Moreover, transcriptome analysis of Escherichia coli after photocatalytic treatment revealed that the underlying photocatalytic antibacterial mechanism at the genetic expression level involves cellular component biosynthesis, energy metabolism, and material transportation. Notably, the differences between BiOCl Ns and BiOCl Uns were significantly enriched in purine metabolism. Therefore, the cost-effective preparation of BiOCl nanosheets with nanoscale thickness-modulated photocatalytic antibacterial activity has remarkable potential for sustainable environmental and biomedical applications. [Display omitted] • BiOCl of different nanoscale thickness is formed under hydrothermal conditions. • BiOCl ultra-nanosheet (Uns) shows the improved photocatalytic ability. • BiOCl nanosheet (Ns) exhibits the best bactericidal effect. • The role of photo reactive species involved in bacterial inactivation is identified. • Gene expression of BiOCl Ns and Uns-treated bacteria differs in purine metabolism. [ABSTRACT FROM AUTHOR]

Perfluorooctanoic acid (PFOA) is a persistent organic pollutant in the environment with serious health risks including endocrine-disrupting characteristics, immunotoxicity, and causing developmental defects. The photocatalytic deposition has proven to be an inexpensive, effective, and sustainable technology for the removal of PFOA in the aqueous phase. Most investigations are conducted in ultrapure water at concentrations higher than those detected in actual water systems. A few studies deal with the toxicity of treated water. In this research, the photocatalytic degradation of PFOA, including photo-oxidative and photo-reductive degradation, is reviewed comprehensively. Compared to photo-oxidation, photo-reduction is more suitable for PFOA removal since it favors defluorination of PFOA and complete mineralization. We used graphene oxide/TiO 2 nanotubes array for photocatalytic degradation of PFOA. The effects of key parameters on the photocatalytic degradation and defluorination processes of PFOA, such as initial PFOA concentration, initial pH of the solution, an initial temperature of the solution, and external bias constant potential, are addressed. We observed that at pH 3 the PFOA degradation was around 83% in 4 h, and at 75 °C almost complete PFOA degradation was observed in 2.5 h. In photoelectrocatalytic process at 2.0 V external bias 97% of PFOA was degraded in 4 h. The mechanisms of the PFOA photodegradation process are also discussed in detail. [ABSTRACT FROM AUTHOR]

The use of antibacterial agents in consumer products may lead to adverse effects in waters receiving treated wastewater. Triclosan is one of the antibacterial agents used widely in the world and its high usage leads to relatively high concentrations in wastewater effluents. In this study, the probable effect of triclosan in receiving waters was assessed using different organisms. The EC50 values were 668 ± 80 μg/L and 7.8 ± 0.1 μg/L, for Vibrio fischeri and Raphidocelis subcapitata , respectively, indicating the higher sensitivity of the alga. The toxicity of triclosan upon exposure to UV light decreased for both species, as suggested by the increase in EC50 values (1300 ± 50 μg/L and 8.7 ± 0.6 μg/L for V. fischeri and R. subcapitata , respectively). The effect of photolysis on toxicity reduction was higher for V. fischeri and the EC50 values were similar for direct and indirect photolysis. LC-MS/MS analysis of samples with and without UV exposure suggested a decrease in triclosan concentration as well as formation of photolysis byproducts upon photolysis. [ABSTRACT FROM AUTHOR]

As climate change and water scarcity continue to be of concern, reuse of treated wastewater is an important water management strategy in many parts of the world, particularly in developing countries and remote communities. Many countries, especially in remote regional areas, use waste stabilisation ponds (WSPs) to treat domestic wastewater for a variety of end uses, including using the treated wastewater for irrigation of public spaces (e.g. parks and ovals) or for crop irrigation. Thus, it is vital that the resulting effluent meets the required quality for beneficial reuse. In this paper, both the performance of WSPs in the removal of organic micropollutants, and the mechanisms of removal, are reviewed. The performance of WSPs in the removal of organic micropollutants was found to be highly variable and influenced by many factors, such as the type and configuration of the ponds, the operational parameters of the treatment plant, the wastewater quality, environmental factors (e.g. sunlight, temperature, redox conditions and pH) and the characteristics of the pollutant. The removal of organic micropollutants from WSPs has been attributed to biodegradation, photodegradation and sorption processes, the majority of which occur in the initial treatment stages (e.g. in the anaerobic or facultative ponds). Out of the many hundreds of organic micropollutants identified in wastewater, only a limited number (40) have been studied in WSPs, with the majority of these pollutants being pharmaceuticals, personal care products and endocrine disrupting compounds. Thus, future research on the fate of organic micropollutants in WSPs should encompass a broader range of micropollutants and include emerging organic pollutants, such as illicit drugs and perfluorinated compounds. Further research is also needed on the formation and toxicity of transformation products from organic micropollutants in WSPs, since the transformation products of some organic micropollutants can be more toxic than the parent compound. Combining other wastewater treatment processes with WSPs for removal of recalcitrant organic micropollutants should also be considered. [ABSTRACT FROM AUTHOR]

In this work, CdS quantum dots (QDs) were successfully confined in polysulfone membrane (PSM) to develop a photoactive membrane under solar illumination that was suited in wastewater remediating system. The CdS@PSM membranes were prepared using the nonsolvent induced phase separation (NIPS) approach. Optical measurements show the confinement of CdS quantum dots (QDs) in the PS matrix within the narrowest band gap (2.41 eV) at 5 wt% loading. PS has two strong emission peaks at 411 and 432 nm due to photoelectron-hole recombination on pure PSM's surface. Adding 1 wt% CdS QDs to PSM reduced the earlier peak and blue-shifted the latter, within the appearance of three emission peaks attributed to the near band-edge emission of confined CdS QDs. Overloading CdS reduced all emission peaks. Moreover, fluorimetric monitoring of •OH radicals indicates that PSM produces the least amount of photogenerated •OH radicals while CdS@PSM(5 wt%) achieved the highest productivity. Examining the developed membranes in detoxifying methylene blue (MB) from aqueous solution of natural pH 8.1 showed weak adsorption in dark over 90 min of contact while switching to solar illumination significantly photodegrade MB where the degradation efficiency starts from 49% for pure PSM to 79% for CdS@PSM(5 wt%). Influence of pH was found crucial on photodegradation efficacy. Acidic pH 3 showed the weakest photodegradation efficacy, while the alkaline pH 12 was 18.88 times more effective. The used CdS@PSM (5 wt%) was successfully photo-renovated by soaking in 10 mL of NaOH solution under Solar illumination for 15 min to be used in 4 consecutive photodegradation cycles with insignificant decrease in efficacy. These findings are promising and could lead to a high-efficiency, sustainable photocatalytic suite. [Display omitted] • CdS@PSM was successfully prepared with varied wt.% of CdS. • Fabricated membranes were tested in solar-driven wastewater remediation. • Incorporated CdS in the PSM resulted in enhanced optical properties and photocatalytic performance. • The CdS@PSM(5 wt%) membrane was found to be perform better. • The photocatalytic membranes showed durable photo-degradation performance. [ABSTRACT FROM AUTHOR]

Recently, the major environmental pollution produced by the release of wastewater in liquid type is one of the most extensive forms of foremost pollution in water ecosystems. In this article, the Bi 2 O 3 /g-C 3 N 4 nanocomposite with a direct Z-scheme was effectively obtained by a facile hydrothermal system. The crystal structures, surface morphology, chemical composition, and the optical belongings of the as-obtained composite catalysts were examined by Power XRD, FT-IR spectra, High-resolution XPS spectra, FE-SEM images with EDX spectra, High-resolution TEM images, UV–Vis DRS, and PL spectra respectively. Furthermore, the photocatalytic performance was assessed by the degradation of aqueous Rhodamine B (Rh B) dye under visible-light exposure. The Bi 2 O 3 /g-C 3 N 4 composite photocatalysts (PCs) showed the maximum photo-degradation efficiency through a rate constant value of 0.0149 min−1, which is 4.9 and 5.3 folds superior to Bi 2 O 3 , and GCN, respectively. The better GBO2 nanocomposite PCs showed a superior photocatalytic degradation performance (>82%) of aqueous Rh B dye after five successive recycles. Moreover, based on these outcomes of the radical scavenging test, a direct and effective Z-scheme photocatalytic charger transfer mechanism was also projected. Finally, the reusability of the as-obtained Bi 2 O 3 /g-C 3 N 4 nanocomposite has better stability and reusability, which was a favourable applicant for wastewater handling. • Bi2O3/g-C3N4 composite Z-scheme catalyst was effectively obtained by facile way. • The superior photocatalytic Rh B dye degradation activity (88.5%) under light exposure. • Reaction rate constant of GBO2 catalyst (0.0149 min-1) is 4.9 folds superior to Bi2O3. • Better recycling stability and durability of Rh B dye after five successive recycles. • Also, an effective Z-scheme photocatalytic charger transfer mechanism was proposed. [ABSTRACT FROM AUTHOR]

In this work, spherical photocatalytic floaters were fabricated by depositing TiO 2 :Bi (TBi) particles on polypropylene (PP) spheres (recycled from beer cans). These particles were deposited on the sphere (TBi-sphere) by the spray coating technique and evaluated their performance for the photocatalytic degradation of 2,4,6-trichlorophenol (2,4,6-TCP) herbicide. SEM images demonstrated that the BTi powders consisted in conglomerated grains with sizes of 20–80 nm and the analysis by X-ray diffraction confirmed the presence of rutile and anatase phases in the BTi. The photocatalytic experiments showed that the TBi and TBi-sphere produced maximum degradation of 90 and 97% for 2,4,6-TCP, respectively, after 4 h under UV–Vis light. The photocatalytic powders/composites were reused 3 times and the loss of degradation efficiency was 3 and 16% for the TBi powder and TBi-sphere, respectively. This means that the TBi-sphere is more stable for the continuous degradation of the 2,4,6-TCP contaminant. The TiO 2 :Bi powder was compared with the commercial TiO 2 (P25) and found that the TiO 2 :Bi powder had higher light absorption (≈42%) and higher surface area (≈105%) than the P25. Therefore, the degradation percentage for the 2,4,6-TCP was 52% higher in the sample doped with Bi. Also, scavenger experiments were carried out and found that the main oxidizing agents produced for the degradation of 2,4,6-TCP were •OH− radicals and •O 2 − anions. Other species such as h+ were also produced at lower amount. Hence, our results demonstrated that spherical/floatable photocatalytic composites are a viable option to remove herbicide residuals from the water, which is of interest in water-treatment-plants. [Display omitted] • Polypropylene (PP) spheres coated with TiO 2 :Bi degraded 2,4,6-TCP by photocatalysis. • TiO 2 :Bi particles produced a maximum degradation of 97% for the 2,4,6-TCP herbicide. • The spherical composite particles produced a maximum degradation of 90% for 2,4,6-TCP. • The main oxidizing agents for the degradation of the 2,4,6-TCP were the.•OH− and •O 2 − • Photocatalytic spheres were reused 3 times and their degradation efficiency decreased only 3%. [ABSTRACT FROM AUTHOR]

Photodegradation of plastic in solid-phase requires the polymer to be composited with an efficient photocatalyst. We report herein the successful synthesis and characterization of fluoride-doped-TiO 2 and its applicability, for the first time, on solid-phase photodegradation of polyethylene films. Nearly half weight loss of polyethylene, containing only 2% of the photocatalyst, is eliminated after three weeks of ultraviolet A radiation using a low consumption light emitting diode lamp, defeating previously reported data. The half-life time of the plastic was around 3 weeks, highlighting the viability of this process for real applications. Results were compared to raw PE and PE composite with well-known TiO 2 , resulting in, respectively, 0 and 26% of weight loss. The degradation process was monitored by optical microscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared and X-ray photoelectron spectroscopy, which revealed the formation of plastic cracks, loss of polyethylene crystallinity and thus stability, the oxidation of C–H bonds and the oxidized state of the surface compounds during photodegradation. The obtained results open a path for the future production of cleaner and self-photodegradable plastics, where the photocatalyst would be introduced in all the manufactured plastics, making possible the quicker photodegradation of the plastics that end up on the environment and the plastics reaching wastewater treatment plants. [Display omitted] • Fluoride-doped TiO 2 was successfully synthesized and composited with PE into films. • The photocatalyst affords solid-phase degradation of half PE material in 3 weeks. • The photodegradation treatment causes oxidation of C–H bonds and cracks in the film. • The photo-based process converts polyethylene into CO 2 and H 2 O end-products. • F–TiO 2 utilization opens a path for the creation of newly photodegradable plastics. [ABSTRACT FROM AUTHOR]

In the present work, two-dimensional bismuth oxybromide (BiOBr) was synthesized and coupled with co-catalyst molybdenum disulphide (MoS 2 ) via a simple hydrothermal process. The photoactivity of the resulting hybrid photocatalyst (MoS 2 /BiOBr) was evaluated under the irradiation of 15 W energy-saving light bulb at ambient condition using Reactive Black 5 (RB5) as model dye solution. The photo-degradation of RB5 by BiOBr loaded with 0.2 wt% MoS 2 (MoBi-2) exhibited more than 1.4 and 5.0 folds of enhancement over pristine BiOBr and titanium dioxide (Degussa, P25), respectively. The increased photocatalytic performance was a result of an efficient migration of excited electrons from BiOBr to MoS 2 , prolonging the electron-hole pairs recombination rate. A possible charge transfer diagram of this hybrid composite photocatalyst, and the reaction mechanism for the photodegradation of RB5 were proposed. [ABSTRACT FROM AUTHOR]

In this work, an activated electric arc furnace slag (A-EAFS) was investigated as an effective Fenton catalyst for the photodegradation of methylene blue (MB) and acid blue 29 (AB29). Fourier transform infrared spectroscopy and UV–visible absorption analyses indicated that A-EAFS offers additional Fe 3 O 4 because of the changes in the iron oxide phase and the favorable response to visible light. It has been found that the highest degradation efficiency can reach up to 94% for MB under optimal conditions of 1 g L −1 of A-EAFS, 20 mM H 2 O 2 , and pH 3. The optimal conditions for AB29 were 0.1 g L −1 A-EAFS, 4 mM H 2 O 2 , and pH 3 to reach 98% degradation efficiency. Visible light enhanced the degradation of both dyes. In addition, A-EAFS, could be easily separated magnetically, exhibited good chemical stability after seven successive photodegradation cycles. [ABSTRACT FROM AUTHOR]

The photo-degradation of the emerging contaminant antipyrine (AP) was studied and optimized in a novel photocatalytic spinning disc reactor (SDR). A heterogeneous process (UV/H 2 O 2 /TiO 2 ) was used. TiO 2 was immobilized on the surface of a glass disc using a sol-gel method. A factorial design of experiments followed by a Neural Networks fitting allowed the optimal conditions to be determined for treating 50 mg/L of AP. Under these conditions (pH = 4; [H 2 O 2 ] 0 = 1500 mg/L; disc speed = 500 rpm; flowrate = 25 mL/s), AP was completely degraded in 120 min and regeneration of the disc allowed 10 cycles with no loss in efficiency. The value of the apparent volumetric rate constant was found to be 6.9·10 −4 s −1 with no apparent mass transfer limitation. Based on the main intermediates identified, a mechanism is proposed for antipyrine photodegradation: Firstly, cleavage of the N N bond of penta-heterocycle leads to the formation of two aromatic acids and N -phenylpropanamide. An attack to the C N bond in the latter compound produces benzenamine. Finally, the phenyl ring of the aromatic intermediates are opened and molecular organic acids are formed. [ABSTRACT FROM AUTHOR]