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WO3/Ag/TiO2 composite photoelectrodes were formed via the high-temperature calcination of a WO3 film, followed by the sputtering of a very thin silver film and deposition of an overlayer of commercial TiO2 nanoparticles. These synthetic photoanodes were characterized in view of the oxidation of a model organic compound glucose combined with the generation of hydrogen at a platinum cathode. During prolonged photoelectrolysis under simulated solar light, these photoanodes demonstrated high and stable photocurrents of ca. 4 mA cm−2 due, on one hand, to the occurrence of the so-called photocurrent doubling and, on the other hand, to the plasmonic effect of Ag nanoparticles. The post-photoelectrolysis analyses of the electrolyte demonstrated the formation of high-value final glucose photo-reforming products, principally gluconic acid, erythrose and formic acid. [ABSTRACT FROM AUTHOR]

The concept of photoelectrochemical conversion of biomass into industrially valuable chemicals presents a compelling strategy to supplant the lower‐value oxygen evolution typically associated with photoanodes. Here, a surface potential manipulation method by regulating the surface oxygen valence states is put forward, which is demonstrated to be effective in enhancing the selective photoelectrochemical oxidation of glycerol to dihydroxyacetone (DHA). This involves the concurrent establishment of a BiVO4/CoOx heterojunction and a BiVO4/Au Schottky junction, aiming to fine‐tune the BiVO4 photoanode's surface potential and improve both its charge carrier separation and interfacial transfer kinetics. The BiVO4/CoOx/Au photoanode exhibits a photocurrent density of 6.15 mA cm−2 at 1.23 V versus reversible hydrogen electrode (RHE). Meanwhile, selective glycerol oxidation efficiency achieves a DHA evolution rate of 339.74 mmol m−2 h−1 and a selectivity exceeding 60%. Experiments and theoretical analysis underscore the pivotal role played by the surface potential in mediating glycerol and DHA adsorption and desorption processes. Additionally, the diminished surface potential attributed to the CoOx and Au amendments is responsible for the decreased Gibbs free energy of the dehydrogenation's rate‐limiting step involving the intermediate carbon species. This work demonstrates a method to design glycerol oxidation catalysts by modulating the interfacial molecular adsorption/desorption by surface potential regulation. [ABSTRACT FROM AUTHOR]

Arbitrary disposal of plastic waste into landfills and oceans can disturb the ecological system and even challenge human survival. Centralized plastic recycling process only works for selected types of plastics (e.g., polyethylene) with limited contribution (<10%), because of high infrastructure requirement. Comparatively, photoreforming of plastic waste for commodity and fuels production is much more facile and decentralizable, and thus holds great potential to mitigate the plastic waste challenge. To this end, a fully solar powered photoelectrochemical system is developed to selectively upgrade polyimide waste (often appears in electronic waste) into valuable commodity chemicals, including succinic acid, acetic acid, and formic acid, and cogenerating green hydrogen fuels. It is also demonstrated that one of the key monomer, pyromellitic acid, and the precious metals (in electronic waste) can be fully recycled. This proof‐of‐concept demonstration provides a new viewpoint for designing decentralized photoelectrochemical system for simultaneous plastic waste upcycling and renewable fuel synthesis, critical for a sustainable plastic economy. Selective cleavage of benzene ring also opens a green route for other benzene ring‐containing waste upgrading. [ABSTRACT FROM AUTHOR]

Background: Cooling towers are specialized heat exchanger devices in which air and water interact closely to cool the water's temperature. However, the cooling water contains organic nutrients that can cause microbial corrosion (MC) on the metal surfaces of the tower. This research explores the combined wastewater treatment approach using electrochemical-oxidation (EO), photo- oxidation (PO), and photoelectrochemical oxidation (PEO) to contain pollutants and prevent MC. Methods: The study employed electro-oxidation, a process involving direct current (DC) power supply, to degrade wastewater. MC studies were conducted using weight loss assessments, scanning electron microscopy (SEM), and x-ray diffraction (XRD). Results: After wastewater is subjected to electro-oxidation for 4 h, a notable decrease in pollutants was observed, with degradation efficiencies of 71, 75, and 96%, respectively. In the wastewater treated by PEO, microbial growth is restricted as the chemical oxygen demand decreases. Discussion: A metagenomics study revealed that bacteria present in the cooling tower water consists of 12% of Nitrospira genus and 22% of Fusobacterium genus. Conclusively, PEO serves as an effective method for treating wastewater, inhibiting microbial growth, degrading pollutants, and protecting metal from biocorrosion. [ABSTRACT FROM AUTHOR]

The integration of clean energy generation with wastewater treatment holds promise for addressing both environmental and energy concerns. Focusing on photocatalytic hydrogen production and wastewater treatment, this study introduces PdIn/TiO2 catalysts for the simultaneous removal of the pharmaceutical contaminant paracetamol (PTM) and hydrogen production. Physicochemical characterization showed a high distribution of Pd and In on the support as well as a high interaction with it. The Pd and In deposition enhance the light absorption capability and significantly improve the hydrogen evolution reaction (HER) in the absence and presence of paracetamol compared to TiO2. On the other hand, the photoelectroxidation of PTM at TiO2 and PdIn/TiO2 follows the full mineralization path and, accordingly, is limited by the adsorption of intermediate species on the electrode surface. Thus, PdIn-doped TiO2 stands out as a promising photoelectrocatalyst, showcasing enhanced physicochemical properties and superior photoelectrocatalytic performance. This underscores its potential for both environmental remediation and sustainable hydrogen production. [ABSTRACT FROM AUTHOR]

BackgroundCooling towers are specialized heat exchanger devices in which air and water interact closely to cool the water's temperature. However, the cooling water contains organic nutrients that can cause microbial corrosion (MC) on the metal surfaces of the tower. This research explores the combined wastewater treatment approach using electrochemical-oxidation (EO), photo-oxidation (PO), and photoelectrochemical oxidation (PEO) to contain pollutants and prevent MC.MethodsThe study employed electro-oxidation, a process involving direct current (DC) power supply, to degrade wastewater. MC studies were conducted using weight loss assessments, scanning electron microscopy (SEM), and x-ray diffraction (XRD).ResultsAfter wastewater is subjected to electro-oxidation for 4 h, a notable decrease in pollutants was observed, with degradation efficiencies of 71, 75, and 96%, respectively. In the wastewater treated by PEO, microbial growth is restricted as the chemical oxygen demand decreases.DiscussionA metagenomics study revealed that bacteria present in the cooling tower water consists of 12% of Nitrospira genus and 22% of Fusobacterium genus. Conclusively, PEO serves as an effective method for treating wastewater, inhibiting microbial growth, degrading pollutants, and protecting metal from biocorrosion.

The photoelectrochemical degradation of selected aromatic substances, acid orange 7 (AO7), salicylic acid (SA), benzoic acid (BA), and 4-chlorophenol (4-CP) was studied on hematite (α-Fe2O3) and compared with titanium dioxide (TiO2), both deposited as thin films on conducting substrates (FTO/glass). Batch type reactors were used under backside and front side illumination. Electrical bias was applied on the semiconducting electrodes, such that only valence band processes leading to oxidative pathways were followed. The initial Faradaic efficiency, f0, of degradation processes was determined from the UV–Vis absorbance decrease of the starting materials. f0 for 1 mM AO7 degradation in 0.01 M sulphuric acid was found to be 7.5%. When the pH of the solution was neutral (pH 7.2) or alkaline (pH 13), f0 decreased to 1.7%. For 1 mM SA, f0 was 6.2% on hematite photoanodes and 6.1% on titanium dioxide. For 1 mM benzoic acid and 4-chlorophenol, f0 was an order of magnitude lower, but only on hematite. This is ascribed to the lack of OH· radical formation on hematite, which seems to be essential for the photooxidation of these compounds. [ABSTRACT FROM AUTHOR]

The photoelectrochemical degradation of selected aromatic substances, acid orange 7 (AO7), salicylic acid (SA), benzoic acid (BA), and 4-chlorophenol (4-CP) was studied on hematite (α-Fe2O3) and compared with titanium dioxide (TiO2), both deposited as thin films on conducting substrates (FTO/glass). Batch type reactors were used under backside and front side illumination. Electrical bias was applied on the semiconducting electrodes, such that only valence band processes leading to oxidative pathways were followed. The initial Faradaic efficiency, f0, of degradation processes was determined from the UV–Vis absorbance decrease of the starting materials. f0 for 1 mM AO7 degradation in 0.01 M sulphuric acid was found to be 7.5%. When the pH of the solution was neutral (pH 7.2) or alkaline (pH 13), f0 decreased to 1.7%. For 1 mM SA, f0 was 6.2% on hematite photoanodes and 6.1% on titanium dioxide. For 1 mM benzoic acid and 4-chlorophenol, f0 was an order of magnitude lower, but only on hematite. This is ascribed to the lack of OH· radical formation on hematite, which seems to be essential for the photooxidation of these compounds. [ABSTRACT FROM AUTHOR]

[Display omitted] • Benzoic acid (BA) and monuron (M) were oxidatively degraded on WO 3 photoanodes. • The course of the degradation was followed by HPLC, UV–VIS and TOC analysis. • The Faradaic efficiency/charge number of degradation of BA and M was calculated. • Salicylic acid was identified as intermediate of benzoic acid degradation. • (3-(4-chlorophenyl)-1-methylurea) was identified as intermediate of monuron degradation. This study describes the photoelectrochemical degradation of model aromatic pollutants, viz. a herbicide ("monuron", 3-(4-chlorophenyl)-1,1-dimethylurea) and an antimicrobial preservative (benzoic acid) on WO 3 films prepared by aerosol pyrolysis. Crystalline WO 3 films had a monoclinic structure, 4 μm thickness and a photocurrent density of 1 mA cm−2 at 1.2 V vs. RHE and illumination under 1 sun (simulated). The chemical and photoelectrochemical stability of WO 3 films at various pH was evaluated. The dissolution rate at pH 1 and 4 was low (0.5 nm·h−1), whereas at pH 6 an increase in the dissolution rate to 15 nm·h−1 was observed. The course of the photoelectrochemical oxidation of selected pollutants was examined using HPLC. The achieved Faradaic efficiency of photoelectrooxidation of 1 mM benzoic acid divided by the number of charge equivalents per 1 mol of oxidised compound R, f/z, was 13 % and 12 % at pH 1 and 4, respectively, and for 1 mM monuron 7.2 % at pH 1 and 7.5 % at pH 4. Although the concentration of pollutants decreased significantly, UV–VIS and TOC (total organic carbon) analyses showed the prevalent presence of intermediates during the degradation. During the degradation of benzoic acid, hydroxybenzoic acid (salicylic acid) was found by HPLC as an early intermediary product. [ABSTRACT FROM AUTHOR]

Coronavirus diseases 2019 (COVID-19), a viral infection pandemic, arises due to easy human-to-human transmission of severe acute respiratory syndrome coronavirus (SARS-CoV-2). The SARS-CoV-2 causes severe respiratory disorders and other life-threatening diseases (during/post-infection) such as black mold disease, diabetes, cardiovascular, and neurological disorders/diseases. COVID-19 infection emerged challenging to control as SARS-CoV-2 transmits through respiratory droplets (> 10 µm size range), aerosols (< 5 µm), airborne, and particulate matter (PM1.0 PM2.5 and PM10.0). SARS-CoV-2 is more infective in indoor premises due to aerodynamics where droplets, aerosols, and PM1.0/2.5/10.0 float for a longer time and distance leading to a higher probability of it entering upper and lower respiratory tracts. To avoid human-to-human transmission, it is essential to trap and destroy SARS-CoV-2 from the air and provide virus-free air that will significantly reduce indoor viral exposure concerns. In this process, an efficient nano-enable photoelectrochemical oxidation (PECO, a destructive approach to neutralize bio-organism) assisted air purification is undoubtedly a good technological choice. This technical perspective explores the role of PECO-assisted Air-Purifiers (i.e., Molekule as a focus example for proof-of-concept) to trap and destroy indoor microorganisms (bacteria and viruses including Coronaviruses), molds, and allergens, and other indoor air pollutants, such as volatile organic compounds (VOCs) and PM1.0/2.5/10.0. It is observed through various standard and non-standard tests that stimuli-responsive nanomaterials coated filter technology traps and destroys microbial particles. Due to technological advancements according to premises requirements and high-performance desired outcomes, Molekule air purifiers, Air Pro Air -Rx, Air Mini, and Air Mini+, have received Food and Drug Administration (FDA) clearance as a Class II medical device for the destruction of bacteria and viruses.

Recirculating air purification technologies are employed as potential means of reducing exposure to aerosol particles and airborne viruses. Toward improved testing of recirculating air purification units, we developed and applied a medium‐scale single‐pass wind tunnel test to examine the size‐dependent collection of particles and the collection and inactivation of viable bovine coronavirus (BCoV, a betacoronavirus), porcine respiratory coronavirus (PRCV, an alphacoronavirus), and influenza A virus (IAV), by a commercial air purification unit. The tested unit, the Molekule Air Mini, incorporates a MERV 16 filter as well as a photoelectrochemical oxidating layer. It was found to have a collection efficiency above 95.8% for all tested particle diameters and flow rates, with collection efficiencies above 99% for supermicrometer particles with the minimum collection efficiency for particles smaller than 100 nm. For all three tested viruses, the physical tracer‐based log reduction was near 2.0 (99% removal). Conversely, the viable virus log reductions were found to be near 4.0 for IAV, 3.0 for BCoV, and 2.5 for PRCV, suggesting additional inactivation in a virus family‐ and genus‐specific manner. In total, this work describes a suite of test methods which can be used to rigorously evaluate the efficacy of recirculating air purification technologies. [ABSTRACT FROM AUTHOR]

Boron-doped diamond materials display excellent electrochemical properties, including large potential windows, low background currents, the ability to withstand extreme potentials, and a strong tendency to resist contamination. These materials have been well-studied in the field of electrochemistry by a variety of methods and advanced characterization techniques. This review highlights recent progress and achievements of boron-doped diamond in photoelectrochemical applications. After surface modification of boron-doped diamond (e.g. with metals, metal oxides, molecular catalysts, enzymes, etc.), boron-doped diamond has demonstrated excellent electrochemical and photoelectrochemical properties. Applications in the fields of photoelectrocatalysis, environmental pollutants degradation, energy conversion and (photo)electroanalysis are discussed. Moreover, the challenges and future research directions of boron-doped diamond photoelectrochemistry are discussed and outlined. This review would provide valuable theoretical guidance for boron-doped diamond photoelectrochemistry. Image 1 [ABSTRACT FROM AUTHOR]

One-dimensional (1D) ordered TiO 2 nanotubes exhibit exceptional charge transfer capabilities, making them suitable candidates for constructing visible-light-active photoanodes in selective PEC oxidation reactions. Herein, we employed a facile and easily scalable electrochemical method to fabricate Au-CoO x -deposited ordered TiO 2 nanotubular array photoanodes. The improved visible light absorption capacity of TiO 2 -Au-CoO x , with unhampered 1D channels and the controlled integration of Au between TiO 2 and CoO x , along with their synergistic interaction, have been identified as the most promising strategy for enhanced PEC performance, as evidenced by an IPCE of 3.7% at 450 nm. Furthermore, the robust interfacial charge transfer pathway from CoO x to the TiO 2 surface via the Au mediator promotes the migration of photogenerated electrons and enables the accumulation of holes on the surface of CoO x . These holes are then efficiently utilized by oxidants such as methanol or lignin to generate value-added products, highlighting the potential of this system for advanced PEC applications.

Owing to its low cost and plentiful different semiconductor configurations resources, photoelectrocatalysis (PEC) has come into the spotlight in large-scale water purification systems. However, the insufficiency of photoelectrocatalytic performance and the issues of long-term durability of current electrode materials are the main bottlenecks for future latent applications. Here, we reported that the multidimensional Ti/SnO2-Sb/PbO2/ZnO nanoarchitecture (PbO2 nanotrees grown on Sb-doped SnO2 nanowires, then ZnO nanowall embedded into PbO2 nanotrees' skeleton) significantly boosts the PEC properties in terms of the organic contaminated water treatment (i.e., reactive brilliant blue KN-R). Benefiting from the synergistic effects of ZnO and PbO2 (the ZnO can be used as the supply station of water, promptly transferring water molecules to adjacent PbO2 to yield hydroxyl radicals), Ti/SnO2-Sb/PbO2/ZnO electrode manifests an unprecedented removal rate of dye, large electroactive areas, noticeable wettability, and high separation efficiency of induced carriers, better stability, which represents a type of promising material in the applications of water purification. [ABSTRACT FROM AUTHOR]

Reasonable hydrophobic anode is deemed to be a promising electrode for photoelectrocatalytic degradation of wastewater. In this study, the C3N4-modified Ti/PbO2 electrode with tunable hydrophobic characteristics is fabricated by a facile electrodeposition process. It is found that the introduction of C3N4 into the PbO2 films changed the morphology, surface hydrophilicity, and hydrophobicity of the electrode, which promotes the photoelectrochemical active areas, generating efficiency of hydroxyl radicals. In addition, introducing C3N4 into PbO2 coating can enhance oxygen evolution potential and carrier density of PbO2. Photoelectrocatalytic degradation experiments show that the addition of C3N4 can further improve the catalytic performance of PbO2 and there exists a significant photoelectric synergism in photoelectrocatalytic process. These results demonstrate that the combination of reasonable surface hydrophobic characteristics and photoelectrocatalytic is a prospective approach for wastewater treatment. [ABSTRACT FROM AUTHOR]

Herein, the Ti/Co3O4 electrodes with n-type semiconductor characteristics were fabricated by a typical hydrothermal process using F− ion as dopant, and their morphology control was also performed by tailoring the hydrothermal temperature. The F− doped Ti/Co3O4 electrodes could be used as photoanode to degrade anthraquinone dye (reactive Brilliant Blue KN-R), and showed excellent photoelectrocatalytic (PEC) activity. It is proposed that the fast ions and electron transportation, high oxygen evolution potential, lower resistance, large active area, and good electrolyte infiltration are responsible for the improved PEC activity of the F− doped Ti/Co3O4 system. Nevertheless, the F− doped Ti/Co3O4 electrode with divergent flower-like structure composed of needle nanowires exhibited highest PEC activity than that of other electrodes. It is noteworthy that the presence of electrostatic anti-barrier arises from an "ohmic" contact between the metal (Ti) and the semiconductor (Co3O4) is also an important factor for the higher PEC activity of the F− doped Ti/Co3O4 electrodes. The work provides unique insight into the design of Co3O4 photoanode from a perspective of tailoring the ion doping and morphology. [ABSTRACT FROM AUTHOR]

Abstract A novel heterostructure of PbO 2 tipped Co 3 O 4 nanowire arrays (NWs) is fabricated by the combination of hydrothermal synthesis and electrochemical deposition. The hydrothermal process is used to fabricate the Co 3 O 4 nanowire arrays (NWs) on the Ti sheet substrates, and subsequently the PbO 2 nanoparticles were preferentially adhered on the sharptip of Co 3 O 4 NWs using an electrochemical deposition method. It is found that the as-constructed PbO 2 /Co 3 O 4 composites exhibit large electroactive areas, low charge transfer resistance, high efficiency regarding the generation of hydroxyl radicals. The photoelectrochemical (PEC) properties of as-constructed PbO 2 /Co 3 O 4 composites were evaluated by the decolorization of dye (reactive brilliant blue KN-R) in aqueous solution. The PEC measurement indicated that as-constructed PbO 2 /Co 3 O 4 composites have higher PEC acitivity, better reproducibility and obvious photoelectric synergism, as compared with bare Co 3 O 4 NWs. The promoted PEC ability for the PbO 2 /Co 3 O 4 composites can be ascribed to the construction of heterointerface between PbO 2 and Co 3 O 4. The present work offered attractive perspectives for applications of the PbO 2 tipped Co 3 O 4 NWs in the photoanode regarding the treatment of refractory organic pollutant. Graphical abstract The PbO 2 tipped Co 3 O 4 nanowire arrays were fabricated by the combination of hydrothermal synthesis and electrochemical deposition methods. The as-constructed PbO 2 /Co 3 O 4 composites have higher PEC acitivity, better reproducibility and obvious photoelectric action, which can be ascribed to the construction of heterointerface between PbO 2 and Co 3 O 4. fx1 Highlights • The PbO 2 tipped Co 3 O 4 nanowire architectures are constructed by hydrothermal-electrochemical process. • The heterointerface between PbO 2 and Co 3 O 4 promoted the separation of induced carriers. • The significant photoelectric synergy existed in PEC process for PbO 2 tipped Co 3 O 4 nanowire arrays. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Dimensionally stable photoelectric anode Sn-Sb-Ti-Ag/SnO 2 -Sb/Ti was designed and fabricated. • Optimized anode showed excellent photoelectrochemical decomposition of phenol. • Properties of optimized hybrid anode suggest its utility in water treatment. Abstract The development of ultra-efficient, sustainable, and easily accessible anode with relative non-precious semiconducting metal oxides is highly significant for application in the practical treatment of organically polluted water. Herein, we report SnO 2 , TiO 2 , and Ag 2 O ternary semiconductor metal oxide blend grafted Ag@AgCl hybrids, prepared with the one-step sol-gel method and applied as a dimensionally stable anode (DSA)-active layer on a SnO 2 -Sb/Ti electrode. Factors affecting crystal formation, including the presence or absence of O 2 during calcination, the calcination temperature, and Ag@AgCl additive dosage were discussed. The micromorphology, phase composition, and photoelectrochemical activity of the newly designed anode were comprehensively characterized. The optimized preparation, which yielded a solid-solution structure with flat and smooth surface and well-crystallized lattice configuration, occurred in the absence of O 2 during calcination at 550 ℃ with an Ag@AgCl additive dosage of 0.2 g in the sol-gel precursor. The newly designed DSA displayed improved electrocatalysis (EC) and photoelectrical catalysis (PEC) capacity. The phenol and its TOC removal efficiency reached 90.65% and 58.17% for 10 mA/cm2 current density with a metal halide lamp in 3 h. The lifespan was four times that of SnO 2 -Sb/Ti electrode. This proposed DSA construction strategy may support improved EC and PEC reactivities toward the decomposition of organic pollutants. [ABSTRACT FROM AUTHOR]

Abstract: This study investigated the influence of oxygen pressure to photoelectrochemical oxidation of the direct black 22 dye using TiO2 nanotube array grown on Ti metal plate as a working electrode, which was fabricated using electrochemical anodization process. The characterization of Titanium nanotube array was carried using X-ray diffraction and scanning electron microscopy techniques. The photoelectrochemical oxidation of direct black dye under increasing pressure from 0.1 to 0.7 MPa was studied; it is found that the increase in oxygen pressure leads to increase in the reaction rate indicating that this may be associated with the electrochemical reduction of oxygen to hydrogen peroxide and other oxygen-containing species. It is further observed that the titanium nanotube array has low electrocatalytic activity.Graphical Abstract: [ABSTRACT FROM AUTHOR]

The conductive carbon black (CCB)-modified Ti/F-PbO2 electrodes were prepared by electrodeposition and characterized systemically using SEM, EDS, XRD, and PL. It is found that the embedding CCB into the PbO2 coating inhibited the growth and aggregation of the PbO2 crystal grains, caused the formation of porous structure and the preferred growth of the (101) and (301) planes of the PbO2 crystal, and enhanced the oxygen evolution overpotential and carrier density of PbO2. The degradation experiment of anthraquinone dye (reactive brilliant blue KN-R) showed that the CCB-modified Ti/F-PbO2 electrodes had higher photoelectrocatalytic activity than that of the bare Ti/F-PbO2 electrode. In addition, the accelerated life measurement demonstrated that the lifetime of the CCB-embedded Ti/F-PbO2 electrode was much longer than that of the bare Ti/F-PbO2 electrode. The improvement of decolorization efficiency and stability of the CCB-modified Ti/F-PbO2 can be attributed to the large active areas, the presence of photoelectric synergism, the inhibition of oxygen precipitation, high current efficiency for formation of hydroxyl radicals, and the weakening of internal stress in PbO2 coatings. [ABSTRACT FROM AUTHOR]

The SnO 2 -Sb 2 O 4 (MMO) and SnO 2 -Sb 2 O 4 -WO 3 (MMO-WO 3 ) electrodes were prepared by electrodeposition followed by dip coating and characterized by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD) analysis. The electrochemical (EC) and photoelectrochemical (PEC) degradation studies were carried out on trypan blue (TB) dye. These studies revealed that the characteristics and performance of MMO electrode improved significantly on nano-WO 3 modification. The oxygen evolution potential (OEP) increased from 2.07 V (vs Ag/AgCl) to 2.21 V and the accelerated service life increased by 1.7 times. 88 and 93% color removal was achieved on electrolysis for 240 min using MMO electrode; whereas, 100% color removal was achieved within 120 min by both EC and PEC using MMO-WO 3 . The percentage chemical oxygen demand (COD) removal achieved using MMO electrode by EC and PEC were only 60 and 63% respectively; whereas, it increased to 78 and 84% with MMO-WO 3 electrode. A probable pathway for TB degradation was proposed on the basis of liquid chromatography–mass spectrometry (LC–MS) analysis and quantum chemical calculations were performed on TB molecule to corroborate the proposed degradation pathway. [ABSTRACT FROM AUTHOR]

• Using Bi 2 O 3 /ZIF-67@GPs composite reduced TC concentration from 20 ppm to 4.6 ppm. • Using the photoelectrochemical oxidation process, 97% was removed from TC. • The presence of cations and mineral anions decreased the rate of TC removal reaction. Tetracycline degradation was investigated using two promising technologies of photocatalysis and photoelectrochemical oxidation through Bi 2 O 3 /ZIF-67 nanocomposite coating on a graphite plat (Bi 2 O 3 /ZIF-67@GP). The physical, chemical and morphological properties of coated graphite plat were determined by XRD, SEM, EDX, CROSS, UV–Vis DRS, and PL. Photocatalytic process in optimal process conditions (pH=4.1, pollutant concentration/load of photocatalyst =0.26 mg.m2/g.L and irradiation time=86 min) showed 77% pollutant removal efficiency. The use of photoelectrochemical oxidation processes has a positive effect on the efficiency of pollutant removal, at optimal conditions (Electrode distance=5.5 mm, pH=4, voltage=1.8 V, Time=89 min, and pollutant concentration/photocatalyst load= 0.2 mg.m2/g.L), the result was showed that 97% tetracycline removal efficiency. The effect of the water matrix including NaCl, Na 2 SO 4 , NaHCO 3 , KCl, MgSO 4 , and CaCl 2 in different concentrations (100–800 mg/L) was recast the initial pH=7, and the pollutant concentration/photocatalyst load=0.2 mg.m2/g.L, and the time=90 min. The investigation and results showed that the presence of inorganic cations and anions caused a constant decrease in the reaction rate. [Display omitted] [ABSTRACT FROM AUTHOR]

Herein, a hydrothermal synthesis of nanocrystalline cobalt tungstate ( m -CoWO 4 ) with mesoporous texture in the presence of amphiphilic organosilane surfactant is described. As-prepared nanocrystals are spherical in shape with size between 8 and 10 nm consisting of monoclinic (wolframite structure) phase. In addition, these nanocrystals are endowed with high surface area (50 m 2 g −1 ), textured mesoporous surface and absorption threshold into visible region. Furthermore, these textured and fine nanocrystals exhibit improved photoelectrochemical activity (PEC), as compared to non-mesoporous CoWO 4 , under visible light (λ>420 nm) for water oxidation in a photoelectrochemical cell. [ABSTRACT FROM AUTHOR]

Nanocrystalline mesoporous nickel tungstate ( m -NiWO 4 ) was synthesized via surfactant assisted hydrothermal templating technique. TEM, HRTEM and N 2 sorption analysis verified the presence of mesoporous textured surface. These nanocrystals were near-spherical in shape with the size variation between 4 and 8 nm, and possessed high surface area (79 m 2 g −1 ). The nanocrystals were in monoclinic (wolframite structure) symmetry and possessed a band gap of 2.6 eV as shown by the XRD and optical measurements. The m -NiWO 4 exhibited much better photoelectrochemical H 2 O oxidation than TiO 2 and non-mesoporous NiWO 4 nanocrystals due to the enhanced crystallinity, surface morphology and mesoporosity. [ABSTRACT FROM AUTHOR]