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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]

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]

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]

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]

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]

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 study photochemical transformation of the antiretroviral pharmaceutical maraviroc under the simulated UV–Vis radiation was presented. The drug was shown to be extremely photo-resistant, with a half-life over 250 h, which is particularly significant, considering its presence in the aquatic environments. Addition of the natural river water matrix substantially increased the degradation rate, albeit the process led to formation of numerous phototransformation products. Due to high photostability and presumable environmental persistence of maraviroc, a photocatalytic method of its elimination was proposed. Although titanium dioxide alone presented acceptable results, its combination with peroxymonosulfate enormously accelerated the degradation process, increasing it over 67 000 times in comparison with the direct photolysis. Substitution of ultrapure water with river water resulted in inhibition of the PMS-driven processes, however the decomposition efficiency was still very high. Noteworthy, majority of the identified photoproducts were still present after termination of irradiation in all the experiments, which may indicate necessity of ecotoxicological assessment of those compounds. [Display omitted] • Transformation of maraviroc under simulated sunlight was studied for the first time. • Studied antiviral drug was found as an extremely photostable compound. • TiO 2 –KHSO 5 photocatalytic system accelerated degradation process over 67 000 times. • 22 phototransformation products were identified using mass spectrometry. • Natural river water matrix significantly alters the photodegradation rate. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the performance of synthesized TiO 2 nanotube arrays (NTAs) for the removal of the COVID-19 aided antibiotic ciprofloxacin (CIP) and the textile dye methylene blue (MB) from model wastewater. Synthesis of TiO 2 NTAs showed that anodization potential and calcination temperatures directly influence nanotube formation. The increased anodization potential from 10 to 40 V resulted in the development of larger porous nanotubes with a diameter of 36–170 nm, while the collapse of the tubular structure was registered at the highest applied potential. Furthermore, it was found that the 500 °C calcination temperature was the most prominent for the formation of the most photocatalytically active TiO 2 NTAs, due to the optimal anatase/rutile ratio of 4.60. The degradation of both model compounds was achieved with all synthesized TiO 2 NTAs; however, the most photocatalytically active NTA sample was produced at 30 V and 500 °C. Compared to photocatalysis, CIP degradation was greatly enhanced by 5–25 times when ozone was introduced to the photocatalytic cell (rates 0.4–4.2 × 10−1 min−1 versus 0.07–0.2 × 10−1 min−1). This resulted in the formation of CIP degradation by-products, with different mass-to-charge ratios from [M+H]+ 346 to 273 m/z. Even though the CIP degradation pathway is rather complex, three main mechanisms, decarboxylation, hydroxylation reaction, and piperazine ring cleavage, were proposed and explained. Furthermore, treated samples were placed in contact with the crustaceans Daphnia magna. It was found that 100% mortality was achieved when approximately 60% of the remaining TOC was present in the samples, indicating that toxic degradation by-products were formed. [Display omitted] • TiO2 NTAs can be applied for effective photocatalytic degradation of ciprofloxacin. • Surface morphology and crystallinity of TiO2 NTAs affected photocatalytic performance. • Introduction of ozone significantly enhanced degradation of ciprofloxacin. • Ciprofloxacin degradation pathways were identified and explained. • Several ciprofloxacin degradation products were found to be toxic to Daphnia Magna. [ABSTRACT FROM AUTHOR]

In this research, we evaluated the photocatalytic performance of biodegradable composites for the removal of the 2,4-Dichlorophenoxyacetic acid (2,4-D) herbicide. The composite was composed by agave fibers (AgF), graphene-microplates (GM) and titanium dioxide TiO 2 /SnO 2 (TSn) nanoparticles (NPs) and was named TSn + AgF/GM. Both, the TSn NPs and the GM were deposited on the AgF using the Dip-coating method. According to the analysis by X-Ray Diffraction (XRD), the crystalline phase for the TiO 2 and SnO 2 was anatase and tetragonal-rutile, respectively. The Scanning Electron Microscopy (SEM) images demonstrated that the AgF were completely saturated by the GM (which had average dimensions of 15 μm × 22 μm) and by conglomerations of TSn NPs with average size of 642 nm. The TSn NPs and the TSn + AgF/GM composite were evaluated for the photocatalytic degradation of the 2,4-D herbicide under ultraviolet–visible (UV–Vis) light and found a maximum degradation of 98.4 and 93.7% (after 4 h) for the TSn NPs and the TSn + AgF/GM composite, respectively. Reuse cycles were also performed and the degradation percentage decreased by 13.1% and by 7.8% (after 3 cycles of reuse) when the TSn NPs and the TSn + AgF/GM composite are employed, respectively. Scavenger experiments were also carried out and found that the oxidizing agents are mainly produced in the order of: •OH>•O 2 − > h+; then, the main oxidizing agents generated during the photocatalytic reaction were the hydroxyl radicals. Thus, the photocatalytic system studied in this work for the degradation of 2,4-D could pave the way for the development of new eco-friendly/floatable photocatalysts, which can be applied in wastewater-treatment plants. [Display omitted] • Photocatalytic composites were made with agave + TiO 2 /SnO 2 nanoparticles (NPs). • Bare TiO 2 /SnO 2 NPs produced a maximum degradation of 98.4% for the 2,4-D herbicide. • The composite of agave + TiO 2 /SnO 2 NPs degraded 93.7% of the 2,4-D contaminant. • Main oxidizing agent produced by the biodegradable composite was the.•OH radical • The biodegradable composite were removed manually from the cleaned water. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO 2)-based nanofibers doped with samarium (Sm3+) and erbium (Er3+) at doping levels tuned in the range of 0.05–1.0% were prepared by the electrospinning-calcination method. The produced materials were well characterized by X-ray diffraction, SEM, EDX, and UV–vis diffuse reflectance spectroscopy. These one-dimensional nanostructures showed a crystalline structure with values of fiber diameters values between 60 and 100 nm. The best catalyst sample of this study was formulated as TiO 2 :Sm (0.1%) and sintered at 600 °C. And, it was employed to intensify the photocatalytic process under visible-light irradiation. Likewise, the chemometric approach was applied to optimize the process. The results revealed that the rate constant for the photo-degradation of a cationic organic pollutant was significantly improved (k = 3.496 × 10−1 min−1). In terms of the reaction half-life, the intensification and optimization of the process led to a decrease in the half-life of the reaction from 68 to 2 min. And, these are outstanding findings for the photo-degradation process under visible-light irradiation. In addition, the total organic carbon (TOC) removal efficiencies were found to be 69.95% and 72.30% for the mineralization of MB and CIP, respectively, after a 360 min reaction time, which are significant results. Moreover, this material demonstrated remarkable photocatalytic activity for the degradation of ciprofloxacin (CIP) with a 99.6% removal efficiency and a rate constant of 4.292 × 10−1 min−1. Finally, the stability and reusability of this catalyst were demonstrated during five repetitive cycles of the CIP photodegradation. [Display omitted] • Sm3+, Er3+:TiO 2 nanostructured materials were prepared by electrospinning method. • The dopants effectively inhibited the growth of crystallites and reduced the E g. • The developed nanostructures have enhanced the photocatalytic activity under visible irradiation. • The process intensification led to a decrease in the half-life from 68 to 2 min. • TOC removal efficiency was found to be 69.95% and 72.30% for the mineralization of MB and CIP. [ABSTRACT FROM AUTHOR]

ZnO nanorod along with a Zn 2 TiO 4 /GO heterostructure with enhanced charge transfer capability was synthesized by a facile sol-gel method. FT-IR, XRD, XPS, TEM, SEM, EDX, UV–Vis DRS, photocurrent response and PL analyses were applied to characterize the as-prepared photocatalysts. To investigate the photocatalytic activity of the composite, Cefixime (CEF) removal under visible light was evaluated. The ZnO nanorod/Zn 2 TiO 4 /GO, including 65 wt% ZnO and 3 wt% graphene oxide, showed the highest CEF degradation and was selected as the optimal ternary composite. Reduction of electron-hole pair recombination rate, successful interfacial charge transfers, and more visible light reception in the Z-scheme system were the important reasons for improving the photocatalytic properties of ZnO nanorod/Zn 2 TiO 4 /GO. Effective operating parameters in the CEF photocatalytic removal process were optimized employing the response surface method and were as follows: photocatalyst dosage = 0.88 g/L, pH = 5, radiation time = 115 min, and CEF concentration = 10 ppm. The photocatalytic degradation% of CEF and total organic carbon (TOC) removal% under the optimal conditions were 71.4 and 57.5%, respectively, for the three-component composite indicating the production of intermediate species during the process. This photocatalytic reaction confirmed the first-order kinetic and using the ZnO nanorod/Zn 2 TiO 4 /GO composite was able to improve the reaction rate by about 2.7 and 6.2 times more than ZnO nanorod/Zn 2 TiO 4 and ZnO, respectively. The effects of radiation intensity and temperature were investigated and 175 W/m2 and 35 °C were obtained as optimum values. Eventually, according to the trapping test, h+, superoxide radical, and hydroxyl radical are the most effective active species in this photocatalytic reaction, respectively. [Display omitted] • The Z-scheme ZnO nanorod/Zn 2 TiO 4 /GO was synthesized via simple sol-gel method. • Enhanced Cefixime visible-light degradation using ZnO nanorod/Zn 2 TiO 4 /GO. • Graphene Oxide had a notable effect on the catalytic behavior of ZnO/Zn 2 TiO 4 in visible light. • The effect of operational parameters in Cefixime photocatalytic degradation were performed. • h+, O 2 − ͦ were the most effective active species in Cefixime photodegradation. [ABSTRACT FROM AUTHOR]

The photocatalytic degradation of p-aminobenzoic acid was studied using TiO 2 nanowires as the catalyst synthesized through a hydrothermal procedure. The as-synthesized TiO 2 nanowires were fully characterized by SEM, TEM, XRD and Raman with a very high surface area of 512 m 2 g −1 . The photocatalytic degradation of p-aminobenzoic acid was carried out under 180 min of constant radiation and the results were compared with P25 as commercial catalyst. Optimal experimental conditions were determined for TiO 2 nanowires with a catalyst dosage of 1.0 g L −1 under acidic conditions with a 20 μM p-aminobenzoic acid solution obtaining 95% of degradation. Under similar experimental conditions comparative studies were performed obtaining 98% of degradation when P25 is employed. In both systems, a pseudo first order reaction was found to provide the best correlations, with constant rates of 2.0 × 10 −2 min −1 and 2.4 × 10 −2 min −1 for TiO 2 nanowires and P25, respectively. [ABSTRACT FROM AUTHOR]

The photocatalytic removal of 2-chlorophenol (2-CP) from water environment was investigated by TiO 2 –RGO–CoO. Cobalt oxide-loaded TiO 2 (TiO 2 –CoO) supported with reduced graphene oxide (RGO) was synthesized using a sol–gel method and then annealed at 500 °C for 5 min. The material characteristics were analyzed by UV–Vis analysis, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy. Incorporation of cobalt oxide and RGO into the TiO 2 system (TiO 2 –RGO–CoO) lowered the band gap energy to 2.83 eV, which greatly enhanced the visible light absorption. The TiO 2 –RGO–CoO photocatalyst showed complete removal of 20 mg/L 2-CP within 8 h with the addition of 0.01% H 2 O 2 under 100 W visible light irradiation. The photo-degradation efficiency of 2-CP (10 mg/L) was 35.2, 48.9, 58.9 and 98.2% for TiO 2 , TiO 2 –RGO, TiO 2 –CoO and TiO 2 –RGO–CoO, respectively, in the presence of visible light irradiation at solution pH of 6.0. The TiO 2 –RGO–CoO photocatalyst retained its high removal efficiency even after five photocatalytic cycles. [ABSTRACT FROM AUTHOR]

The efficient remediation of pharmaceuticals, including wastewater, remains a remarkably challenging issue for water regeneration. Herein, porous Au/TiO 2 synthesized by pyrolysis of NH 2 -MIL-125(Ti) was utilized to be an efficient photocatalyst for mineralization of trimethoprim (TMP) and Metronidazole (MNZ) as the parent compound. The effects of different factors, including TMP and MNZ concentrations, light intensity, H 2 O 2 concentration, Au/TiO 2 dosage, and pH value of reaction solution on the degradation and mineralization performances during UV and visible light (VIS), were addressed. The porous Au/TiO 2 photocatalyst exhibited superior photocatalytic degradation of TMP and MNZ under UV and VIS illumination. The optimum pH values were 4; the optimum dosage of Au/TiO 2 was 1.5 g/L, H 2 O 2 concentration was 9.8 mM, TMP and MNZ concentrations was 10 ppm, and their photodegradation efficiency was 100% after 30 min illumination time and mineralization efficiency 98.2% after 3 h illumination for TMP and MNZ, respectively under UV illumination, however, the photodegradation efficiency was 100% after 50 min illumination and mineralization efficiency 96.3% after 4.5 h illumination time for TMP and MNZ, respectively under VIS illumination. The real wastewater matrix with 10 mg/L of TMP and MNZ were subjected to 60 min of illumination under similar optimum conditions of synthetic solution. The results indicated that photodegradation efficiency was determined to be 100% after 70 min illumination time for removal of both TMP (k = 3.4 × 10−2 min−1) and MNZ (k = 2.87 × 10−2 min−1). This is ascribed to the incorporation of Au NPs onto TiO 2, reducing the photoinduced electron-hole recombination, thus promoting the photocatalytic performance. The possible mechanism for photodegradation of antibiotics was also discussed. The demonstration of photocatalysis mechanism over Au/TiO 2 photocatalyst can provide some directing in the enhancement of novel photocatalysts based on MOFs doped by noble metal. [Display omitted] • Porous TiO 2 NPs was derived from NH 2 -MIL-125(Ti) through pyrolysis strategy. • 0.1%Au/TiO 2 was assessed for mineralization of two antibiotics in real wastewater. • The reaction process over Au/TiO 2 was optimized by investigating different factors. • Complete mineralization of two antibiotics (100%) was achieved by UV and VIS light. • 0.1% Au/TiO 2 photocatalyst showed high stability and recyclability for four cycles. [ABSTRACT FROM AUTHOR]

This paper reports on the synthesis, characterization and adsorption properties of a novel nano-composite obtained using the hydrothermal method applied to a fly ash-TiO 2 slurry and hexadecyltrimethyl-ammonium bromide, as surface controlling agent. The new adsorbent was investigated in terms of crystallinity (XRD), surface properties (AFM, SEM, and porosity and BET surface) and surface chemistry (EDX, FTIR). The nanocomposite's properties were sequentially tested in adsorption and photocatalysis processes applied to multi-pollutant synthetic wastewaters loaded with copper cations and two industrial dyes: the acid dye Bemacid Blau and the reactive dye Bemacid Rot; the nano-composite substrate allowed reaching high removal efficiencies, above 90%, both in adsorption and in photodegradation experiments, in optimised conditions. [ABSTRACT FROM AUTHOR]

The presence of antibiotics in waste and drinking water is causing increasing concern around the world, thereby an advanced sustainable technology needs to be developed to eliminate the antibiotics from water resources. Hence, an efficient spinning disc photoreactor (SDPR) equipped with visible light-activated Ag/Ag 2 O/TiO 2 heterostructure thin film photocatalyst was assessed for the degradation of amoxicillin (AMX) as a typical antibiotic. The surface morphology, optoelectronic and structural features of Ag/Ag 2 O/TiO 2 heterojunction were characterized by TEM, BET, mott Schottky, FESEM, EDS, AFM, XRD, UV–Vis-DRS, and contact angle measurements. Results confirm that Ag and Ag 2 O have a significant effect on the photocharge carrier separation and transfer of the as-developed photocatalyst system. The operative variables including illumination time, rotational speed, solution flow rate, aeration rate, pH, and initial AMX concentration were optimized by CCD. The results displayed the maximum AMX photodegradation (97.91%) could be achieved at optimal conditions involving illumination time of 80 min, a rotational speed of 225 rpm, the solution flow rate of 0.6 L/min, aeration rate of 20 L/min, pH = 6, and initial AMX concentration of 20 mg/L. Interestingly, more than 79% COD and 64% TOC were removed under optimum conditions during 80 min illumination time, respectively. Active species tests confirmed the dominant role of ·OH and ·O 2 − in AMX degradation. finally, the XRD pattern confirmed that the reusability assessments of the heterojunction film could successfully retain its stability for six consecutive photocatalytic degradation runs. This work demonstrates the feasibility of utilizing visible-light-driven thin-film photocatalysts in spinning disc photoreactors in treating the tenacious antibiotic pollutants. • A new spinning disc photocatalytic reactor (SDPR) was applied to the degradation of amoxicillin (AMX). • Ag/Ag 2 O/TiO 2 heterojunction deposited on a spinning ceramic disc was applied as photocatalytic system. • The AMX was degraded up to 97% under visible light illumination. [ABSTRACT FROM AUTHOR]

Abstract: Sulfonylurea herbicides (SUHs) are a family of environmentally compatible herbicides but their high water solubility, moderate to high mobility through the soil profile, and slow degradation rate make them potential contaminants of groundwater as demonstrated in this paper. The photodegradation of a mixture of 30 SUHs in aqueous suspensions of semiconductor materials (ZnO and TiO2 in tandem with Na2S2O8 as electron acceptor) under artificial light (300–460 nm) irradiation was investigated. As expected, the influence of both semiconductors on the degradation of SUHs was very significant in all cases. Photocatalytic experiments show that the addition of photocatalyst, especially for the ZnO/Na2S2O8 system, greatly improves the removal of SUHs compared with photolytic tests, significantly increasing the reaction rates. The first-order equation (monophasic model) satisfactorily explained the disappearance process although it overlooked small residues remaining late in the process. These residues are important from an environmental point of view and the Hoerl function (biphasic model), was a better predicter of the results obtained. In our conditions, the average time required for 90% degradation was about 3 and 30 min for ZnO/Na2S2O8 and TiO2/Na2S2O8 systems, respectively. [Copyright &y& Elsevier]

Herein, a green and facile methodology was used for the structural design of semiconductor nanomaterials and employed as efficient photocatalyst to resolve the environmental issues of water pollutants. Titanium oxide coupled with bismuth oxide (TiO 2 @Bi 2 O 3) nanocomposite was synthesized by employing the seed extract of Sapindus mukorossi (commonly found plant in India) and subsequently used for the elimination of toxic, and persistence industrial pollutants namely bisphenol A (BPA) and methylene blue (MB). Microscopic and spectroscopic techniques revealed particle size of synthesized nanocomposite found less than 50 nm along with high crystallinity. Appearance of stretching vibrations at 459 cm−1 for Bi–O–Ti in the IR spectra of nanocomposite has established the coupling of TiO 2 with Bi 2 O 3. The parameters of degradation were optimized by varying the pollutant concentration, catalytic amount and pH in the presence of natural sunlight. The nanocomposite TiO 2 @Bi 2 O 3 showed maximum degradation (MB: 94% and BPA: 91%) at a minimum concentration of pollutant (50 mgL−1) with catalyst amount (35 mg), neutral pH and reduces half-life of pollutants (BPA: 1h, MB: 0.5h). Owing of higher surface area (80 m2g-1), lower band gap (2.5 eV), and more negative zeta potential value (−40.3 mV) results into excellent photocatalytic properties. The breakage of S–N conjugated system in MB results into rapid degradation as compare to BPA. The degradation followed first-order kinetics and Langmuir adsorption in both the cases. Presence of active radicals during the photocatalysis process was responsible for quick degradation and strongly supported by scavenger analysis. GC-MS analysis revealed the degradation of toxic pollutants into safer metabolites and finally mineralized. Multiple times (n = 8) reusability of green photocatalyst advocated sustainability and appropriate for industrial applications. [Display omitted] • Natural extract based synthesis of TiO 2 @Bi 2 O 3 nanocomposite. • First-order degradation of Bisphenol A (91%) and Methylene Blue (MB) dye(9 4%) by TiO 2 @Bi 2 O 3. • Optimization of concentration, pH, catalyst dose and source of irradiation. • Hybrid nanostructure increased charge separation and prevent e−/h + recombination behavior. • Small non-toxic by-products and excellent reusability (8th cycle) confirm high efficiency. [ABSTRACT FROM AUTHOR]

Abstract: The adsorption and photodegradation of acridine orange (AO) and acriflavine (AF) dyes on two mesoporous titania crystalline phases, anatase and rutile, were experimentally studied. Anatase and rutile were characterized by nitrogen adsorption, electron scanning and transmission microscopy, and X-ray diffraction. The adsorption capacity of rutile was higher than that of anatase, while the reverse is observed for photodegradation of both dyes. The adsorption of AF on both adsorbents was higher than that of AO, which was related with the smaller size of AF molecules compared with those of AO, therefore the access of AF to the adsorption sites is favored. [Copyright &y& Elsevier]

A mixture of nine pharmaceuticals has been treated by means of the systems: UV-B(313 nm), O3, UV-B(313 nm) + TiO2, O3 + UV-B(313 nm), and O3 + UV-B(313 nm)+TiO2. Simple photolytic or ozonation processes lead to a deficient total organic carbon (TOC) elimination after 120 min of exposure (25 and 30% conversions, respectively). Addition of a photocatalyst such as titanium dioxide significantly enhanced the mineralization degree, a 60% TOC conversion was obtained. A TiO2 load optimum around 0.25 g L−1 was observed. No loss in photoactivity was experienced after 2 reuses. Due to ozone photodegradation, the combination of ozone and radiation increased the generation of hydroxyl radicals. As a consequence, TOC removal was increased to a value in the proximity of 85%. The most complex system, O3 + UV-B(313 nm) + TiO2, achieved the highest TOC abatement (95%). Use of ozone in photocatalytic processes involves an increase in hydroxyl radical generation. [Copyright &y& Elsevier]

The N-doped TiO2 photocatalyst was prepared by calcination of a hydrolysis product composed of titanium (IV) isopropoxide with ammonia as the precipitator. X-ray diffraction, surface area, XPS and UV–vis spectra analyses showed a nanosized anatase structure and the appearance of a new absorption band in the visible region caused by nitrogen doping. The degradation of Direct Black 38 dye on the nitrogen-doped TiO2 photocatalyst was investigated under visible light and sunlight irradiation. The N-doped anatase TiO2 demonstrated excellent photocatalytic activity under visible light. Under sunlight irradiation, the N-doped sample showed slightly higher activity than that of the non-doped sample. [Copyright &y& Elsevier]

Photocatalytic degradation of phenol on different phases of TiO2 particles was examined under 400-W UV irradiation. The effects of various operating parameters including TiO2 dosage, solution pH (4–10), and initial phenol concentration (0.13–1.05 mM) on phenol degradation were investigated. Three forms of TiO2 photocatalysts such as pure anatase phase, pure rutile phase, and the mixed phase were prepared by sol-gel method and followed annealing at different temperatures. The annealing temperature used were 500 °C, 700 °C and 900 °C for pure anatase phase, the mixed phase, and pure rutile phase, respectively. It was shown that pure anatase TiO2 exhibited higher photocatalytic activity than the physical mixture of pure anatase and rutile TiO2. Moreover, the TiO2 particle with a specific fraction of mixed anatase and rutile phases exhibited better performance than pure anatase TiO2. Finally, the degradation rate could be satisfactorily fitted by a pseudo-first-order kinetic model. [Copyright &y& Elsevier]

In this work, Er3+:YAlO3/ZnO–TiO2 and ZnO–TiO2 composites were prepared by the ultrasonic dispersion and liquid boiling method. In succession, they were then characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Acid red B as a model dye compound was degraded under solar light irradiation to evaluate the photocatalytic activities of the Er3+:YAlO3/ZnO–TiO2 and ZnO–TiO2 composites. We found that the photocatalytic activity of ZnO–TiO2 composite can be enhanced by adding an appropriate amount of Er3+:YAlO3. We reviewed influencing factors, such as Er3+:YAlO3 content, heat-treated temperature and heat-treated time on the photocatalytic activity of the Er3+:YAlO3/ZnO–TiO2 composites. In addition, the effects of solar light irradiation time, dye initial concentration, Er3+:YAlO3/ZnO–TiO2 amount and solution acidity on the photocatalytic degradation of acid red B dye in aqueous solution were investigated in detail. Simultaneously, the degradation and comparison of other dyes such as methyl orange (MO), rhodamine B (RM-B), azo fuchsine (AF), congo red (CG-R) and methyl blue (MB) were also reviewed. In addition, we attempted to explore both the principle of possible excitation of Er3+:YAlO3/ZnO–TiO2 under solar light irradiation and the mechanism of photocatalytic degradation. [Copyright &y& Elsevier]