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Pharmaceutical industry wastewater is causing an increased risk of resistant pharmaceutical micropollutants (PMP) e.g. antibiotic resistant bacteria (super bug) in the ecosystem. Amongst variety of wastewater treatment approaches, Advanced oxidation processes (AOPs) employing photocatalysis provides a cost-effective and sustainable approach for fixation of PMP in an economical and efficient manner to counter the potential risks. Until today, tremendous efforts have been made to trig the performance of photocatalytic wastewater treatment, with the key focus on development of cost-effective, efficient and a moderately stable photocatalyst. Such attempts succeeded with different types of photocatalysts using different synthesis techniques. In recent years, graphitic carbon nitride (GCN) has emerged as one of the cost effective, moderately stable, nontoxic and efficient photocatalyst, and has been scarcely studied specifically for pharmaceutical micropollutants (PMPs) degradation. Hence, considering these factors alongside the facile synthesis and moderate optical absorption of GCN, an effort was made in the present work with effective customization of GCN i.e. silver (Ag) doping to extend light absorption in visible light range which may enhance the photocatalytic performance for Ciprofloxacin (CIP) degradation. The optimization of photocatalytic performance was executed with varied Ag dopant content to obtain an optimum sample with supreme photocatalytic activity for the maximum degradation of CIP, a common antibiotic. The best Ag-doped GCN sample (0.1 AGCN) exhibits a photocatalytic degradation efficiency of 84%, which is 2.15 times greater than pure GCN (39%). The obtained results showed that the strategy of Ag doping substantially enhances the photocatalytic performance, thus offering an efficient mean for developing visible light active photocatalyst for PMP removal and encouraging further research. The photocatalytic performance of the prepared samples was evaluated by degradation of CIP under visible light irradiation. Several characterization techniques were used to characterize and analyze the prepared samples, such as X-ray diffraction (XRD), Scanning electron microscopy (SEM), Raman spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, UV Visible absorption, and Photoluminescence (PL) spectroscopy.

Visible light active co-doped Cu-N/TiO2 photocatalyst was synthesized by the sol-gel method. The synthesized catalysts were characterized by X-ray diffraction (XRD), field-emission transmission electron microscope (FE-TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and UV–visible diffuse reflectance spectrophotometry (UV-vis DRS). The co-doping with Cu-N reduced the bandgap (∼2.83 eV) and extended the optical absorption range of TiO2 catalysts to the visible region. The incorporation of Cu and N on TiO2 lattice results in sub-conduction and valence band formation, which enhanced the photoactivity and electron-hole generation rate. The visible light activity of Cu-N/TiO2 was evaluated via photocatalytic degradation of bisphenol A (BPA) under blue LED illumination. The maximum BPA degradation of 42.7% was observed at 0.5 g L−1 catalyst dosage, initial pH of BPA solution = 8.2, and initial BPA concentration of 10 ppm. Further, a possible mechanism of photocatalytic degradation of BPA was also established. HIGHLIGHTS Co-doped Cu-N/TiO2 nanoparticles were used for the photocatalytic degradation of bisphenol A.; Enhanced visible light activity was achieved with co-doping of Cu and N on TiO2.; Comprehensive characterization of the catalyst and effect of major operational parameters on degradation efficiency were studied.; At optimum conditions maximum bisphenol A degradation of 42.7% was observed.;

The nano-interface formed by bimetallic Cu@Ag nanoparticles (NPs) on a TiO 2 surface enhances charge separation through plasmonic heterojunctions. These bimetallic Cu@Ag NPs were synthesized via the a galvanic replacement reaction (GRR) involving Ag+ in an aqueous medium and metallic Cu NPs on TiO 2. During the GRR, Cuδ+ and Agδ+ charge pairs are generated by electron transfer from the catalyst surface. These charge pairs act as active sites, significantly enhancing photocatalytic hydrogen production. Additionally, the cubic crystalline phase of metallic Cu NPs is maintained after the GRR process with Ag ions, while the size of bimetallic Cu@Ag NPs remains constant. Consequently, Cu@Ag NPs supported on TiO 2 (Cu@Ag:TiO 2) exhibit increased donor charge density of 1.66 × 1020 cm−3 and facilitate rapid charge transfer. As a result, the photocatalytic hydrogen production rate of Cu@Ag:TiO 2 is 20 times higher than that of pristine TiO 2. Moreover, the visible-light responsive photocatalytic activity of Cu@Ag:TiO 2 NPs reaches 3.4 mmol g−1 over 5 hours, which is 78 times higher than that of pristine TiO 2. This remarkable enhancement is attributed to the formation of a plasmonic heterojunction with close contact between Cu@Ag and TiO 2 , enabling efficient charge carrier separation. [Display omitted] • The Cuδ+ and Agδ+ charge pairs formed via the galvanic replacement reaction increase donor charge density. • Development of a nanointerface with core-shell Cu@Ag bimetallic NPs on TiO 2 facilitates effective charge separation. • Core-shell Cu@Ag NPs serve as efficient light harvesting centers on TiO 2 , establishing a plasmon heterojunction. • Bimetallic Cu@Ag:TiO 2 exhibits a 78-fold increase in H 2 production under visible light compared to pristine TiO 2. [ABSTRACT FROM AUTHOR]

Hydrogen (H 2) emerges as a highly promising contender for replacing conventional fossil fuels due to its high combustion heat value and net-zero greenhouse gas emission. Photocatalytic H 2 generation through semiconductor-based water splitting represents a clean and sustainable technology in the field. Developing highly efficient and abundant source semiconductor materials, along with co-catalysts, is paramount in achieving the industrial-level H 2 evolution by photocatalysis technology. In recent years, transition-metal phosphides (TMPs) have emerged as powerful co-catalysts for photocatalytic reactions due to their cost-effectiveness, abundant reserves in the earth's crust, and favorable physicochemical properties, thus offering a viable alternative to conventional precious metal materials. In this review, we first provide a concise historical overview and outline the structure of TMPs. The synthetic strategies of TMPs are subsequently systematically analyzed based on diverse phosphorus sources. Additionally, this review provides a comprehensive summary of the recent research endeavors conducted on TMPs as potential photocatalytic co-catalysts for efficient hydrogen generation through photocatalysis. Eventually, this review briefly addresses the prevailing key concerns, proposed countermeasures, and forthcoming challenges associated with enhancing the efficiency of photocatalytic H 2 evolution in TMPs. • Applications of TMP materials in photocatalytic H 2 production fields were reviewed. • Synthetic approach of TMP materials were summarized based on distinct phosphorus sources. • The related mechanisms during reaction process of TMP materials were discussed. • Challenges and prospect of TMP materials toward photocatalytic H 2 evolution were presented. [ABSTRACT FROM AUTHOR]

Photocatalysis is one of the most preferred methods for the degradation of organic pollutants as it can lead to complete mineralization of organic pollutants employing sunlight as an energy source. Until so far enormous number of investigations have been done regarding the development of visible light responsive, stable, and cost effective photocatalysts. In the present work, owing to objectives mentioned above, an attempt was made to develop an efficient, cheaper, and visible light active composite photocatalyst consisting of moderate band gap, CuWO4 with electron conductive graphene quantum dots. A series of photocatalysts was prepared by varying the amount of CuWO4 while keeping the amount of GQDs fixed, and their activity was evaluated for the phenol degradation under visible light irradiation. The prepared photocatalysts were characterized by using X-ray diffraction (XRD), Scanning electron microscopy (SEM), Raman spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, and Photoluminescence (PL) for the evaluation of crystallinity, functional groups, and properties of charge carrier separation, respectively. The maximum efficiency of photodegradation of phenol simulated wastewater was achieved by sample 0.5GCW (optimized sample having 0.5 wt% of CuWO4 with respect to fixed amount of GQDs), 53.41%, as compared to the pure CuWO4 sample, which exhibited 19.08% efficiency. A possible mechanism for enhanced activity of CuWO4 is proposed mainly due to efficient transfer of electrons from CuWO4 to graphene quantum dots. The results show that the graphene quantum dots GQDs with the CuWO4 significantly contributes to the improvement of photocatalytic performance.

The photocatalysts area aims for feasible clean-renewable energy generation, targeting new low-cost and straightforward manufacturing of visible light-responsive materials by developing organic and inorganic novel composites. This work shows a novel approach, exploring three widely used commercially available powders (SiC, SiOC, and TiO 2) to build a ternary-component system based on the polymer-derived ceramic (PDC) pathway. Furthermore, the results disclose the phases' interplay and synergetic effects that improve the composites' catalytic activity. The interaction between Si and Ti atoms in the composite system decreases the bandgap from 3.2 eV to 2.89 eV, increasing the ceramic yield from 51% to 86% while hindering the TiO 2 anatase-to-rutile transformation. The SiC–SiOC–TiO 2 interplay boosts the visible-light-driven hydrogen generation through photoreforming for hydrogen generation up to approximately 5-fold compared to pristine TiO 2. In addition, the synthesis reported herein provides a straightforward and practical approach by increasing existing catalysts' activity toward visible-light-driven hydrogen generation systems and facilitates further filtration processes. [Display omitted] [ABSTRACT FROM AUTHOR]

Industrial wastewater contamination is a severe global issue due to the effective dosage of textile dyes that are directly exiting from the textile industries either without treatment or mild treatment. These dyes contain many organic pollutants severely damaging human beings along with aquatic environment and animals. Methylene blue (MB) dye is a carcinogenic that can cause acute diseases. In this regard, Photocatalysis proves an alluring approach because to its fascinating characteristics over ordinary technologies particularly economical and simple methodology. Layered double hydroxide (LDH) as a photocatalysts are exhibiting their promising performance for the treatment of organic pollutant in industrial wastewater. The present research displays a simple and facile co-precipitation method for the synthesis pure Co-Al LDH and its composite with graphene oxide (GO). A series of composites of GO and Co-Al layered doubled hydroxide with varied content of GO is successfully synthesized that enhanced the photocatalytic performance of Co-Al LDH in terms of MB dye degradation. With the optimized sample, 0.5 g GO loading onto Co-Al LDH termed as 0.5-CAL/GO, the MB dye degradation of 71 % was achieved under white LED light (10 W) irradiation. Synthesized photocatalysts are characterized by several analytical techniques such as (XRD, SEM, FTIR, Raman, UV Visible DRS, Photoluminescence spectroscopy). This research presents the flexible strategy for effective removal of MB dye simulated wastewater, acting as a textile industry wastewater employing a visible light active photocatalyst under white light (LED) illumination.

Cu and Ag enhance the photocatalytic activities of metal–organic frameworks (MOFs) toward CO 2 conversion because of their CO 2 adsorption capacities and effects on the lowest unoccupied molecular orbital (LUMO) overpotentials of MOFs. However, to date, targeted introduction of metals into MOFs to achieve visible (Vis)-light-active photocatalysts for CO 2 photoconversion has not been realized. Herein, a series of amine-functionalized Ti MOF (NH 2 -MIL-125(Ti))-based photocatalysts were successfully synthesized using metalation, incorporation, and photodeposition, allowing Cu and Ag incorporation into NH 2 -MIL-125(Ti) and attainment of ultraviolet- and Vis-light-active photocatalysts. Notably, the most active photocatalyst obtained by post-synthetic metalation of NH 2 -MIL-125(Ti) by Cu2+ (MOF_met_0.5%Cu) demonstrated excellent performance in photoreducing CO 2 to HCOOH: a conversion rate of 30.1 umolg−1h−1 and quantum yield of 1.18% at 380 nm. Photoconversion of CO 2 to HCOOH was further confirmed using 13CO 2. The novel approach proposed herein is a significant step toward clean energy production and environmental pollutant elimination. [Display omitted] • 0.5%Cu-metalized NH 2 -MIL-125 generated 30.1 µmol g−1 h−1 HCOOH under visible light. • MOF photocatalytic activity increased with Cu and decreased with Ag modification. • Photoconversion of CO 2 to formic acid was confirmed using 13CO 2 • Apparent quantum efficiency reached 1.18% for MOF_met_0.5%Cu excited at 380 nm. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) nanostructures have been synthesized using zinc acetate dehydrate and deionised water as precursors by the hydrothermal method. To investigate the morphology and size of the ZnO nanostructures, different concentrations of organic ligand hydrazine hydrate were added as a passivating agent to the precursor solution. The crystal structure of the synthesized samples were analysed by X-ray diffractometer. The influence of variation of hydrazine hydrate concentration in the synthesized samples has been investigated from the field emission scanning electron microscope images. From the diffuse reflectance spectroscopy studies, the optical absorption and band gap of the samples were determined. The samples were examined for morphology and size dependent photocatalytic activity against the degradation of methylene blue organic dye under visible light irradiation. [ABSTRACT FROM AUTHOR]

Thin layers of BiVO4/V2O5 were prepared on FTO substrates using pulsed laser deposition technique. The method of cobalt hexacyanocobaltate (Cohcc) synthesis on the BiVO4/V2O5 photoanodes consists of cobalt deposition followed by electrochemical oxidation of metallic Co in K3[Co(CN)6] aqueous electrolyte. The modified electrodes were tested as photoanodes for water oxidation under simulated sunlight irradiation. Deposited films were characterized using UV-Vis spectroscopy, Raman spectroscopy, and scanning electron microscopy. Since the V2O5 is characterized by a narrower energy bandgap than BiVO4, the presence of V2O5 shifts absorption edge (ΔE = ~0.25 eV) of modified films towards lower energies enabling the conversion of a wider range of solar radiation. The formation of heterojunction increases photocurrent of water oxidation measured at 1.2 V vs Ag/AgCl (3 M KCl) to over 1 mA cm-2, while bare BiVO4 and V2O5 exhibit 0.37 and 0.08 mA cm-2, respectively. On the other hand, the modification of obtained layers with Cohcc shifts onset potential of photocurrent generation into a cathodic direction. As a result, the photocurrent enhancement at a wide range of applied potential was achieved. [ABSTRACT FROM AUTHOR]

Pharmaceutical industry wastewater is causing an increased risk of resistant pharmaceutical micropollutants (PMP) e.g. antibiotic resistant bacteria (super bug) in the ecosystem. Amongst variety of wastewater treatment approaches, Advanced oxidation processes (AOPs) employing photocatalysis provides a cost-effective and sustainable approach for fixation of PMP in an economical and efficient manner to counter the potential risks. Until today, tremendous efforts have been made to trig the performance of photocatalytic wastewater treatment, with the key focus on development of cost-effective, efficient and a moderately stable photocatalyst. Such attempts succeeded with different types of photocatalysts using different synthesis techniques. In recent years, graphitic carbon nitride (GCN) has emerged as one of the cost effective, moderately stable, nontoxic and efficient photocatalyst, and has been scarcely studied specifically for pharmaceutical micropollutants (PMPs) degradation. Hence, considering these factors alongside the facile synthesis and moderate optical absorption of GCN, an effort was made in the present work with effective customization of GCN i.e. silver (Ag) doping to extend light absorption in visible light range which may enhance the photocatalytic performance for Ciprofloxacin (CIP) degradation. The optimization of photocatalytic performance was executed with varied Ag dopant content to obtain an optimum sample with supreme photocatalytic activity for the maximum degradation of CIP, a common antibiotic. The best Ag-doped GCN sample (0.1 AGCN) exhibits a photocatalytic degradation efficiency of 84%, which is 2.15 times greater than pure GCN (39%). The obtained results showed that the strategy of Ag doping substantially enhances the photocatalytic performance, thus offering an efficient mean for developing visible light active photocatalyst for PMP removal and encouraging further research. The photocatalytic performance of the prepared samples was evaluated by degradation of CIP under visible light irradiation. Several characterization techniques were used to characterize and analyze the prepared samples, such as X-ray diffraction (XRD), Scanning electron microscopy (SEM), Raman spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, UV Visible absorption, and Photoluminescence (PL) spectroscopy. [ABSTRACT FROM AUTHOR]

Researchers have focused on efficient techniques for degrading hazardous organic pollutants due to their negative impacts on ecological systems, necessitating immediate remediation. Specifically, TiO 2 -based photocatalysts, a wide-bandgap semiconductor material, have been extensively studied for their application in environmental remediation. However, the extensive band gap energy and speedy reattachment of electron (e−) and hole (h+) pairs in bare TiO 2 are considered major disadvantages for photocatalysis. This review extensively focuses on the combination of semiconducting photocatalysts for commercial outcomes to develop efficient heterojunctions with high photocatalytic activity by minimizing the e−/h+ recombination rate. The improved activity of these heterojunctions is due to their greater surface area, rich active sites, narrow band gap, and high light-harvesting tendency. In this context, strategies for increasing visible light activity, including doping with metals and non-metals, surface modifications, morphology control, composite formation, heterojunction formation, bandgap engineering, surface plasmon resonance, and optimizing reaction conditions are discussed. Furthermore, this review critically assesses the latest developments in TiO 2 photocatalysts for the efficient decomposition of various organic contaminants from wastewater, such as pharmaceutical waste, dyes, pesticides, aromatic hydrocarbons, and halo compounds. This review implies that doping is an effective, economical, and simple process for TiO 2 nanostructures and that a heterogeneous photocatalytic mechanism is an eco-friendly substitute for the removal of various pollutants. This review provides valuable insights for researchers involved in the development of efficient photocatalysts for environmental remediation. [Display omitted] • Photocatalysis is an efficient techniques for degrading hazardous pollutants. • TiO 2 based photocatalyst was thoroughly investigated. • Synthesis methods of pristine and engineered TiO 2 explored. • Doping is an effective strategy to reduce band gap of TiO 2. • Reviewed the TiO 2 based materials for environmental remediation. [ABSTRACT FROM AUTHOR]

In the present work Cu 2 O shape tailored microcrystals were obtained and investigated. The used shape-tailoring approach was based upon the variation of the starting precursor (copper(II) acetate and copper(II) chloride, the latter one being also much more cheaper and easily accessible), the synthesis temperature (60, 70 and 80 °C, respectively) and the shape tailoring agent applied (PVP vs. EDTA). It was found that cubic and polyhedral monodisperse microcrystals were obtained, which showed enhance visible light photocatalytic activity in the degradation of methyl orange. The activity was dependent of the formation of metallic Cu (the formed metallic nanoparticles were obtained when PVP was used), the microcrystals' size and morphology. The band-gap values were directly linkable to the obtained photocatalytic activity, while in the first derivative DRS spectra the electron transition contribution of facet (111) was also found, alongside of the polycrystalline Cu 2 O electron transition contribution. Also, the surface hydrophylicity played a crucial role in the determination of the photocatalytic properties as evidenced by IR measurements and DLS investigations as well. Unlabelled Image • The nature of the precursor predetermined the Cu 2 O microparticles' morphology • Hydrophylicity was a key issue in the determination of the Cu 2 O's photoactivity • Shape-tailored Cu 2 O's (111) facet influenced the visible light absorption properties • EDTA stabilized efficiently Cu 2 O microparticles, inhibiting metallic Cu formation [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Proofs for the titanates photosensitization with the surface charge transfer Ti-complexes. • The surface CT complexes photosensitize titanates under Vis as well as UV light. • The visible-light induced photocatalytic activity of materials is as high as under UV. • High improvement of the photocurrents generation under UV light by the surface complexation. Abstract For the first time, photosensitization of selected alkaline titanates with surface charge transfer complexes has been proven. Activation of BaTiO 3 , SrTiO 3 and CaTiO 3 to visible as well as ultraviolet light has been achieved by impregnation with catechol, salicylic acid and 2,3-naphthalenediol. Simple modification of titanates with organic compounds forming inner-sphere CT complexes with Ti atoms located at the surface of semiconductors resulted in coloration of the materials. Even though acceptor electronic states of titanates are characterized by a higher energy compared with titania (even up to 0.75 eV higher for CaTiO 3), complexes formed at their surface absorb in similar or even broader optical range of visible light. Beside changes in the absorption properties, used modifications also strongly influenced their photoelectrochemical and photocatalytic properties. In contrast to similarly modified titanium dioxide, modified titanates show significantly improved photocatalytic activity not only under visible light but also within ultraviolet range of radiation. Remarkably increased efficiency of photocurrent generation within the UV range of radiation may suggest that apart from observed electron transfer from HOMO of the complex to conduction band (CB) of the semiconductor also an indirect photosensitization mechanism involving the electron transfer from the excited complexes to the CB of titanates may take place. [ABSTRACT FROM AUTHOR]

Abstract Cu-doped WO 3 electrode was fabricated on FTO substrate via one step preparation by modified sol-gel method using a suspension of [(NH 4) 10 H 2 (W 2 O 7) 6 ] and CuSO 4 ·5H 2 O in mix of polyethylene glycol 300 and ethylene glycol. Photoelectrocatalytic degradation of bisphenol A (BPA) with Cu-doped WO 3 electrode was performed under visible light irradiation and H 2 O 2 as auxiliary oxidizing agent. For monitoring of the photoelectrocatalysis it was used conventional and alternative method (UV–Vis spectrophotometry and electrochemical sensor, respectively). After 8 h of assay, it was verified removal of 80% of BPA and formation of the phenolic intermediates using electrochemical sensor and 75% of total carbon organic removal. Graphical abstract Unlabelled Image Highlights • Cu doped WO 3 electrodes were synthesized successfully by sol gel modified method. • The electrode was applied in the BPA photodegradation with 75% of TOC removal. • Electrochemical sensor (NiO/MWCNT/GCE) was used for monitoring of the BPA decay and intermediates formed. [ABSTRACT FROM AUTHOR]

Abstract Bismuth vanadate thin films deposited using the pulsed laser deposition technique were modified using cobalt hexacyanocobaltate (Cohcc). The 2-step method of Cohcc nanocubes preparation was applied: i) metallic cobalt deposition and ii) cobalt electrooxidation in Co(CN) 6 3− containing electrolyte. The presence of CN stretching vibrations was confirmed by Raman spectroscopy. The energy band gap was equal to 2.5 eV and was estimated using UV–Vis spectroscopy. The presence of Cohcc did not clearly affect the absorbance ability of tested films. Electrodes were tested as photoanodes for water splitting. It was shown that electrocatalytical properties of Cohcc in the oxygen evolution reaction strongly affect the photocurrent generated during FTO/BiVO 4 /Cohcc illumination. A significant, almost 1 V, shift of the onset potential towards lower potential was achieved. The role of Cohcc has been discussed on the basis of electrochemical and photoelectrochemical measurements. Graphical abstract Image 1 Highlights • The two-step method of Cohcc nanocubes deposition on BiVO 4 was developed. • Cohcc deposited on BiVO 4 exhibits catalytic activity in the oxygen evolution reaction. • BiVO 4 /Cohcc has an almost 1 V lower onset potential of photocurrent generation. • The presence of Cohcc positively affects charge extraction efficiency. • A lower R CT of the electrode/electrolyte interface was achieved for modified electrodes. [ABSTRACT FROM AUTHOR]

In the present work, shape tailored Cu2O microparticles were synthesized by changing the nature of the reducing agent and studied subsequently. d-(+)-glucose, d-(+)-fructose, d-(+)xylose, d-(+)-galactose, and d-(+)-arabinose were chosen as reducing agents due to their different reducing abilities. The morpho-structural characteristics were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and diffuse reflectance spectroscopy (DRS), while their photocatalytic activity was evaluated by methyl orange degradation under visible light (120 min). The results show that the number of carbon atoms in the sugars affect the morphology and particle size (from 250 nm to 1.2 µm), and differences in their degree of crystallinity and photocatalytic activity were also found. The highest activity was observed when glucose was used as the reducing agent.

In our work, we employed Cs3Bi2I9 as a visible-light-active photocatalyst, synthesized with a low-temperature solvothermal method. The morphological and structural properties of the as-prepared perovskite were investigated, and the results were compared to previous studies to confirm its nature and the quality of the synthesis procedure. Transient absorption spectroscopy was applied in order to investigate the generation and lifetime of photogenerated charge carriers, revealing their formation after visible light excitation. The potential photocatalytic activity of the as-prepared metal halide perovskite was applied for the removal of Rhodamine B in aqueous solution, demonstrating an excellent activity of 93% after 180 min under visible-light irradiation. The current research aims to provide insights into the design of a new visible-light-active photocatalyst, Cs3Bi2I9, selected for its high application value in the field of advanced materials for light harvesting.

Abstract TiO 2 nano-wires (Ti-NWs) and nano-flakes (Ti-NFs) were obtained from phosphorus doped TiO 2 nanoparticles (Ti-P) by hydrothermal method and by subsequent heat treatment respectively. FE-SEM micrograph of the as prepared sample depicts well formed, entangled and randomly oriented nano-wires morphology, which changes to nano-flakes morphology after heat treatment. Structural characterization of the samples by X-ray diffraction shows anatase phase for both the samples. Absorption edge of the Ti-NWs sample shows blueshift where as the Ti-NFs sample exhibit redshift compared to precursor sample as evidenced by UV–Visible absorption spectra, which is due to change in morphology and crystallinity of the samples. XPS studies indicate the presence of titanium and oxygen species only. From the EPR measurements with in-situ visible light irradiation, the number of photogenerated charge carriers is found to be very high for nano-flakes sample. Methyleneblue degradation profiles depict very high activity of Ti-NFs sample compared to Ti-NWs and the precursor samples, which is due to the observed redshift in the absorption edge, change in morphology and high crystallinity of the sample which in turn increases the optical response and separation of photogenerated charge carriers as evidenced by the optical and EPR measurements respectively. [ABSTRACT FROM AUTHOR]

A series of CuC 2 O 4 /TiO 2 heterostructures with different mass ratio have been prepared via a simple precipitation method. Compared to bare P25 TiO 2 and pure CuC 2 O 4 , the as-prepared CuC 2 O 4 /TiO 2 exhibited superior activity and stability for the degradation of propylene under visible light. Results of X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectroscopy (DRS) indicated that there is an intimate interaction between CuC 2 O 4 and P25 TiO 2 nanoparticles by means of the coordination bond of O on the surface of TiO 2 with Cu atom in CuC 2 O 4 molecular. The strong activity of CuC 2 O 4 /TiO 2 heterostructure is due to the interfacial charge transfer (IFCT) from the valence band of the TiO 2 to the CuC 2 O 4 nanoparticles. In addition, compared to Cu (II)/TiO 2 synthesized using the same amount of CuSO 4 solution, CuC 2 O 4 /TiO 2 exhibited much higher visible light activity for the degradation of propylene because of higher atom ratio of Cu to Ti, more visible light absorption and stronger action between CuC 2 O 4 and TiO 2 . [ABSTRACT FROM AUTHOR]

Regardless of the fact that tungsten trioxide (WO 3 ) is recognized as one of the most promising photocatalysts for potential activity under visible light illumination, it still suffers from intrinsic drawbacks such as photocorrision and an unsuitable band gap structure for the reduction of molecular oxygen. To overcome these limitations we herein report for the first time in-situ synthesized WO 3 nanoparticles which were coupled with commercial TiO 2 (P25) via a simple impregnation method. The surface of the composites were additionally grafted with varying contents (0.005–0.3 wt%) of Fe(III) nanoclusters with their synergistic performance being investigated. The photocatalytic activities of the obtained materials were evaluated by monitoring the decomposition of the model compounds nitric oxide (NO) and acetaldehyde under UV and visible light illumination. A significant improvement of visible light sensitivity was attained in comparison with bare WO 3 /TiO 2 . Additionally the synthesized photocatalysts have been characterized by using x-ray powder diffraction(XRD), transmission electron microscopy (TEM), electron paramagnetic resonance (EPR) spectroscopy, UV–vis diffuse reflectance spectroscopy and N 2 adsorption (BET) for specific surface area determination. The EPR results confirmed a direct charge transfer from the VB of the composites to the surface grafted Fe(III) nanoclusters, which are promoting multi-electron reduction processes consequently resulting in the degradation of harmful gases. [ABSTRACT FROM AUTHOR]

Abstract: Visible‐light‐driven H2 production from pure water is highly promising but unfortunately inefficient. Herein, for the first time, we report the realization of pure‐water‐splitting H2 production under visible‐light irradiation via single‐component CdS without any cocatalysts, employing a piezoelectric‐photocatalysis strategy. Wurtzite CdS nanorod arrays that combine piezoelectric and visible‐light photocatalytic properties was in‐situ assembled on FTO substrates to harvest both solar energy and ultrasonic vibration energy in water. The ultrasound‐induced piezoelectric field in CdS drives the separation of photo‐generated charge carriers, leading to more facile water‐splitting for H2 evolution than that under visible‐light irradiation alone. The CdS nanorod arrays achieves a high H2 production rate of 20 μL.h−1 under optimized coupling field, which is much higher than that of unsupported samples. This work demonstrates the capability of piezoelectric photocatalysts to simultaneously convert visible light energy and acoustic energy into hydrogen energy, which may break a new ground for the design of energy‐conversion materials towards harvesting discrete ambient energy in urban environment. [ABSTRACT FROM AUTHOR]

This study explores a novel photocatalytic approach for the conversion of complex biomass into smaller molecular units for their utility in generation of biofuel precursors. Following hydrothermal method, TiO 2 /Bi 2 WO 6 nanocomposite photocatalyst for different ratio of TiO 2 viz. 15% and 25% by weight have been synthesized. The efficiency of photodegradation of organic molecule is determined. Composite loaded with 25% TiO 2 found to represent maximum photocatalytic efficiency of 99.9%. The structural and optical properties of the synthesized photocatalyst nanomaterial were characterized. A band gap of 2.7 eV was observed for 25% TiO 2 composition which displayed an excellent visible light photoactivity, examined by removal of Rhodamine B. We further observe a four-fold higher photocatalytic activity in this composite compared to pristine Bi 2 WO 6 . Using this composite, solar energy is harvested to perform photocatalytic fragmentation of a biopolymer, namely starch, to derive smaller molecule precursors. Colorimetric analysis of reducing sugars from the degraded biomass quantifies the monomarization of starch. The linear chain molecular fragments thus formed were further analyzed by Raman, FTIR and ESI-MS. The results demonstrate photocatalytic pretreatment of starch by nanocomposite of TiO 2 /Bi 2 WO 6 resulted in the formation of organic precursors that are common feedstock for the microbiota of anaerobic methanation and ethanol fermentation. We therefore conclude that photocatalytic pretreatment of biomass can be utilized for hydrolysis and partial acedogenesis of biomass in biofuel conversion processes. Such an approach represent environmentally benign way to convert biomass waste to biofuel. [ABSTRACT FROM AUTHOR]

Tungsten and nitrogen co‐doped TiO2 nanobelts (W/N‐TNBs) have been successfully synthesized via 1‐step hydrothermal method. The structure, morphology, and composition of prepared samples were characterized by X‐ray diffraction, scanning electron microscopy, and X‐ray photoelectron spectroscopy, respectively. The prominent phase of all as‐prepared samples is anatase crystal. For samples with N doping, new energy states can be introduced on top of O 2p states which reduced the band gap by 1.1 eV. The reduced band gap leads to efficient visible light activity. The 3%‐W/N‐TNBs were found to exhibit the highest activity. The photocatalytic performance of 3%‐W/N‐TNBs under visible light is about 4.8 times than that of pure TiO2 nanobelts, which emphasizes the synergistic effect of W and N co‐doping for effectively inhibiting the recombination of photogenerated electrons and holes. In addition, our results testify the different redox potentials of the photoelectrons at different final states. [ABSTRACT FROM AUTHOR]

[Display omitted] • BiOI microflower/Bi metal junctions were grown using a solvothermal process. • Their photocatalytic activity towards NO was examined under UVA and visible light. • The effect of Bi particle size on the activity, from the nano- to micron-scale, was examined. • The nanoparticulate Bi sample showed an NO conversion of ∼26% under visible light. • This visible light activity was > 6 times higher than a commercial TiO 2 benchmark. Herein, we investigate the effect of Bi particle size in BiOI/Bi junctions on their photocatalytic function towards NO gas. BiOI microflowers (BiOI) and BiOI microflowers decorated with micron-sized Bi particles (BiOI/Bi MPs) were produced by a solvothermal method. BiOI decorated with nano-sized Bi particles (BiOI/Bi NPs) were produced by a reduction process. All samples were physically characterised by XRD, FT-IR, SEM, HR-TEM coupled with EDX analysis, DR-UV–visible and PL spectroscopy and functionally characterised by photocatalytic testing towards NO gas, TAS and EPR spectroscopy. Their photocatalytic activity towards NO gas was measured following ISO protocol (ISO 22197–1:2016). The best performing BiOI-based sample was BiOI/Bi NPs, showing NO and NO x conversion efficiencies of ∼33 and ∼11% under UVA light, and ∼26 and ∼8.1% under visible light, respectively. The BiOI and BiOI/Bi MPs samples showed significantly lower activities, displaying overall NO x conversion efficiencies of ∼3.5 and ∼0.8% under UVA light, respectively. Importantly, the best performing BiOI/Bi NPs samples showed visible light activity that was at least 6 times higher than that of a commercial TiO 2 benchmark (CristalACTiVTM PC-S7). TAS measurements showed that charge carriers were significantly longer lived in the BiOI/Bi NPs sample (t 50% from 10 μs of ∼90 μs) than the BiOI and BiOI/Bi MPs samples (t 50% from 10 μs of ∼50 μs). This was attributed to the significant degree of interfacial contact formed between Bi and BiOI in the BiOI/Bi NPs sample, which enhanced charge carrier separation. EPR studies showed that this interfacial contact between BiOI and Bi likely promoted the formation of V O , which may have contributed to enhancement seen in photocatalytic activity in the BiOI/Bi junction. [ABSTRACT FROM AUTHOR]

SrTiO 3 nanocube and three dimensional, mesoporous BiOBr catalysts were synthesized by sol-gel and precipitation methods respectively. Various weight percentages of SrTiO 3 -BiOBr heterojunction composite catalysts (x% SrTiO 3 -BiOBr where x = 5, 10, 30, 50 & 70 percentage of SrTiO 3 ) were synthesized by impregnation method. All the synthesized catalysts were characterized by various instrumental techniques. The results of PL and EIS indicate that the heterojunction catalyst, 10% SrTiO 3 -BiOBr (10-ST/BB), has the lowest recombination rate of e − - h + pairs and the lowest electron transfer resistance respectively. Photocatalytic activities of the synthesized catalysts were tested towards the degradation of carcinogenic reactive dyes such as reactive blue 198, reactive black 5 and reactive yellow 145 in presence of visible and solar irradiations. Among the catalysts 10-ST/BB resulted in the highest photocatalytic activity towards the degradation of all the three dyes. Kinetics studies on degradation indicated that it followed pseudo first order. The efficiency of dye degradation was found to be better in the presence of solar light than under visible light degradation due to ≃ 4% UV light in solar irradiation. TOC, HPLC and COD studies confirm that the dyes are mineralized into some organic salts such as acetates, formates, etc., CO 2 , water and salts. [ABSTRACT FROM AUTHOR]

Low temperature pure anatase Carbon Doped Titanium Dioxide (C-TiO2) is successfully synthesized by using starch as an effective, economical, and nonhazardous carbon source. The synthesized C-TiO2 has been further characterized by X-Ray Diffraction, SEM, TEM, BET, XPS and UV- DRS techniques, which reveal that the particles are crystalline with spherical morphology, high surface area and an optical band gap of 2.79eV for C-TiO2 calcined at 400°C. Furthermore photocatalytic degradation of Rhodamine B dye was carried out using as-prepared C-TiO2 under visible light irradiation. Prepared C-TiO2 calcined at 200°C and 400°C show higher degradation efficiency (85% and 100% in 120min respectively) as compared to that of undoped TiO2 and commercial Degussa P-25. Result shows that the C-TiO2 containing lower carbon percentage has higher photocatalytic activity. Thus enhanced photocatalytic activity of C-TiO2, may be due to synergic effect of carbon doping and [101] facet enhanced synthesis of anatase C-TiO2. [ABSTRACT FROM AUTHOR]

Photocatalysis has been shown to be effective for the disinfection of water contaminated with pathogenic microorganisms. In order to increase the solar efficiency of photocatalysis on titanium dioxide (TiO 2 ) it is necessary to modify the TiO 2 so that visible photons may be utilised in addition to the UV. TiO 2 – reduced graphene oxide composites (TiO 2 -rGO) were prepared by the photocatalytic reduction of exfoliated graphene oxide (GO) using P25 (Evonik-Aeroxide) as the photocatalyst. The composites were tested for the inactivation of E. coli as the model microorganism under UV–Vis and visible only irradiation at relatively low light intensities to help elucidate the mechanism of disinfection. The results showed a 6 log inactivation of E. coli after 120 min of treatment with unmodified TiO 2 -P25 and the same level of inactivation was achieved after 90 min with TiO 2 -rGO under UV–Vis irradiation. Under visible irradiation only, the TiO 2 -rGO gave a 5.3 log inactivation of E. coli following 180 min of treatment whereas the unmodified P25 gave only a 1.7 log-reduction in the same time, similar to that observed in the light control. Using probes, the main reactive oxygen species involved in the disinfection process were determined to be hydrogen peroxide, hydroxyl radicals, and singlet oxygen under UV–Vis irradiation; and only singlet oxygen under visible only irradiation. Scavenger studies were also performed to further elucidate the mechanism of disinfection. [ABSTRACT FROM AUTHOR]

The photocatalytic degradation of pollutants is a key technological application for nanomaterials. Our work aims at developing a multifunctional nanocrystalline heterostructure based on TiO 2 nanorods, Fe x O y and Ag nanoparticles (NPs), TiO 2 NRs/Fe x O y /Ag, integrating in one nanostructure a visible light photoactive moiety (TiO 2 NRs/Ag) and a magnetic domain (Fe x O y ), in order to address the photoactivity under visible light and the possibility of recovery and reuse the photocatalyst. The synthesis was carried by preparing first the TiO 2 NRs/Fe x O y based heterostructure and then growing Ag NPs with control on size. The resulting multidomain structures were characterized by FTIR and absorption spectroscopy, TEM and SEM microscopy, EDS and XRD analysis. The influence of the Ag NP domain and of its size on the photoactivity of the TiO 2 NRs/Fe x O y /Ag nanostructures under visible light were investigated in the photocatalytic degradation of the Nalidixic Acid, an antibiotic used as a model compound representative of recalcitrant pollutants. In the presence of the Ag domain a significant increase of the photoactivity with respect to TiO 2 NRs/Fe x O y heterostructures and to the commercially available TiO 2 P25 was observed. Such an enhanced photocatalytic efficiency was found dependent on the size of the Ag domain and explained taking into account the plasmonic properties and the different possible photoactivation mechanisms. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cost-effective dihydroxyanthraquinones can sensitize TiO 2 to visible light. • 1,5-, 1,8-dihydroxyanthraquinones are the most active and stable modifiers of TiO 2. • Materials exhibit activity against Gram(+), Gram(−) bacteria, and fungi. • Addition of KI in PDI tests causes a superb bactericidal and fungicidal activity. • TiO 2 modified with dihydroxyanthraquinones can photogenerate HO and 1O 2. Materials based on titanium(IV) oxide and four dihydroxyanthraquinones were synthesized using a simple impregnation method. The dyes (1,2-, 1,4-, 1,5- and 1,8-dihydroxyanthraquinone) did not alter the physical properties of bare TiO 2 , but photosensitized it to visible light, up to 600 nm. The materials exhibit good photocatalytic activity in this spectral range. Adsorbed 1,5- and 1,8-dihydroxyanthraquinones revealed exceptional stability compared to previously described semiconductors modified with organic compounds. The spectroscopic characterization of the synthesized materials indicates that photosensitization occurs via an indirect electron transfer mechanism. To exploit their promising properties, appropriate tests were carried out towards the photodynamic inactivation of microorganisms. It was found that upon excitation with green light the tested photomaterials exhibited remarkable activity (3–4 log units) against Gram-negative and Gram-positive bacteria, as well as fungi. Moreover, the addition of inert potassium iodide to the photocatalytic system led to the complete eradication (>7 log units) of studied microorganisms. Elaborated materials appeared exceptionally photoactive under visible light, photostable, and cost-effective and therefore can be considered promising photocatalysts for environmental and biomedical applications. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C 3 N 4) is a visible light active photo-catalyst, but its photo-catalytic efficiency is hampered by rapid recombination of the photo-induced charge carriers in g-C 3 N 4. This adverse charge recombination of g-C 3 N 4 is efficiently retarded by compositing g-C 3 N 4 with cadmium selenide (CdSe). The energy band gap of CdSe is narrower than that of g-C 3 N 4, and also its band positions are compatible with g-C 3 N 4 in order to carry out the lateral intersystem crossing of the photo-induced electrons from the conduction band of g-C 3 N 4 to that of CdSe. In this work, g-C 3 N 4 /CdSe nanocomposites with four different CdSe mass loading (1%, 2.5%, 5%, and 10%) were synthesized by pulsed laser induced method, where laser fragmentation (LFL), and laser defect engineering (LDL) are the underlying processes. The structural, morphological, and elemental characterizations using XRD, TEM, FE-SEM, and EDX confirmed the proper anchoring of CdSe nanoparticles on the g-C 3 N 4 polymeric surface. The modified band structure in the g-C 3 N 4 /CdSe nanocomposite not only enhanced the visible light absorption, but also effectively retarded the photo-induced charge recombination, which are reflected in the optical absorption spectra, and the photoluminescence spectra respectively. Photo-catalytic degradations of Rhodamine B (RhB), and methylene blue (MB) dyes under visible light in the presence of four different variants of g-C 3 N 4 /CdSe nanocomposites were estimated, and bench marked with pure g-C 3 N 4. As anticipated, the photo-catalytic degradation efficiency of all the variants of g-C 3 N 4 /CdSe nanocomposites is significantly higher than that with pure g-C 3 N 4. The highest photo-catalytic degradation rate constant of 0.0222 min−1, 0.0178 min−1 respectively for MB and RhB were achieved using g-C 3 N 4 /CdSe nanocomposite with 2.5% CdSe mass content. As a second application, g-C 3 N 4 /CdSe nanocomposite was also used in the electrocatalytic hydrogen evolution process in the acidic medium. Thin this study, the observed over potential recorded was lower for g-C 3 N 4 /CdSe nanocomposite than that with pure g-C 3 N 4, indicating the higher hydrogen evolution capability of this nanocomposite as the electro-catalyst. [Display omitted] [ABSTRACT FROM AUTHOR]

• Visible light active photocatalyst composite, CuWO 4 /GQDs synthesized successfully by a facile approach. • The photocatalytic performance evaluated via degradation of organic pollutant i.e., phenol. • The photocatalytic performance is optimized according to varied weight of main photocatalysts CuWO 4 in composite sample. • GQDs in composite photocatalyst provides an efficient pathway for charge separation. • The performance enhancement is mainly attributed to efficient charge separation. Photocatalysis is one of the most preferred methods for the degradation of organic pollutants as it can lead to complete mineralization of organic pollutants employing sunlight as an energy source. Until so far enormous number of investigations have been done regarding the development of visible light responsive, stable, and cost effective photocatalysts. In the present work, owing to objectives mentioned above, an attempt was made to develop an efficient, cheaper, and visible light active composite photocatalyst consisting of moderate band gap, CuWO 4 with electron conductive graphene quantum dots. A series of photocatalysts was prepared by varying the amount of CuWO 4 while keeping the amount of GQDs fixed, and their activity was evaluated for the phenol degradation under visible light irradiation. The prepared photocatalysts were characterized by using X-ray diffraction (XRD), Scanning electron microscopy (SEM), Raman spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, and Photoluminescence (PL) for the evaluation of crystallinity, functional groups, and properties of charge carrier separation, respectively. The maximum efficiency of photodegradation of phenol simulated wastewater was achieved by sample 0.5GCW (optimized sample having 0.5 wt% of CuWO 4 with respect to fixed amount of GQDs), 53.41%, as compared to the pure CuWO 4 sample, which exhibited 19.08% efficiency. A possible mechanism for enhanced activity of CuWO 4 is proposed mainly due to efficient transfer of electrons from CuWO 4 to graphene quantum dots. The results show that the graphene quantum dots GQDs with the CuWO 4 significantly contributes to the improvement of photocatalytic performance. [ABSTRACT FROM AUTHOR]

The one-pot co-condensation of tetrabutyl orthotitanate (TBOT) and the neutral Ru(II) N3 dye or the new cationic Ir(III) complex [Ir(ppy) 2 (3,3′-H 2 dcbpy)]PF 6 have yielded novel hybrid in-situ titanias, which present an exceptional stability against leaching or photodegradation of the coordination dye. The main advantages of this strategy are: i) high dye incorporation level, ii) narrowing band gap and iii) high stability. These materials exhibit much higher photocatalytic activity, under both UV and visible light, not only than the dye-free titania but also than the related dye-sensitized titania prepared by post-synthetic grafting. This in-situ synthetic approach is a promising alternative route to prepare highly stable dye-sensitized materials with great applicability potential. [ABSTRACT FROM AUTHOR]

Lanthanum tantalum niobium oxynitride [La(Ta,Nb)O 2 N] powders were prepared with different Nb/Ta ratios by conventional solid state reaction. La(Ta,Nb)O 2 N photoanodes were fabricated by electrophoretic deposition of La(Ta,Nb)O 2 N suspension in acetone onto ITO substrate. The La(Ta,Nb)O 2 N photoanodes were found to exhibit photoelectrochemical activity for water oxidation reaction in alkaline solution. Subsequently, a cobalt-phosphate based oxygen evolution catalyst (CoPi-OEC) was photodeposited onto the surface of the La(Ta,Nb)O 2 N catalyst to improve the photoelectrochemical performance. In the presence of CoPi catalyst, the photocurrent-voltage characteristics of the La(Ta,Nb)O 2 N electrodes were enhanced with its effect more pronounced at lower potentials. A stable photocurrent density of 20 mA/cm 2 at 1.2 V vs SCE was achieved under the illumination using alkaline phosphate solution with pH 13. Relative to the La(Ta,Nb)O 2 N photoanodes, nearly three times higher photocurrent density was observed at 1.2 V vs SCE for a CoPi/La(Ta,Nb)O 2 N photoelectrode. Perovskite-based oxide-nitrides modified with suitable cocatalyst of CoPi, have been shown as a new pathway towards substantial photoelectrochemical current gain during the PEC water splitting reaction. [ABSTRACT FROM AUTHOR]

The present report deals with the effect of nitrogen doping on TiO 2 –SiO 2 mixed oxide photocatalysts. Advantageous effect of mixing SiO 2 with TiO 2 and subsequent N doping on the visible light photocatalysis is discussed. Hydrazine is used as the nitrogen doping source. Mixed Oxide to hydrazine ratio is varied from 1:2 to 1:8 to study the hydrazine concentration effect on the surface and photocatalytic properties. Presence of silica increases the surface area and thermal stability of anatase phase whereas nitrogen doping enhances the visible light absorption. Presence of substitutional nitrogen and oxygen vacancy in TiO 2 lattice is due to the use of hydrazine which is also a reducing agent. Material prepared with 1:6 hydrazine ratio (TiSi-6N) shows surface area of 260 m 2 /g and light absorption up to 520 nm. Under visible light only TiSi-6N is able to completely reduce Se(VI) into its elemental form within 90 min of reaction. [ABSTRACT FROM AUTHOR]

• Visible light active photocatalyst composite, CO-Al LDH/GO synthesized successfully by a facile approach. • The photocatalytic performance evaluated via degradation of organic dye i.e. methylene blue. • The photocatalytic performance is optimized according to varied weight of GO in composite sample. • GO content in composite photocatalyst provides an efficient pathway for charge separation. • The performance enhancement is mainly attributed to the optical absorption and efficient charge separation. Industrial wastewater contamination is a severe global issue due to the effective dosage of textile dyes that are directly exiting from the textile industries either without treatment or mild treatment. These dyes contain many organic pollutants severely damaging human beings along with aquatic environment and animals. Methylene blue (MB) dye is a carcinogenic that can cause acute diseases. In this regard, Photocatalysis proves an alluring approach because to its fascinating characteristics over ordinary technologies particularly economical and simple methodology. Layered double hydroxide (LDH) as a photocatalysts are exhibiting their promising performance for the treatment of organic pollutant in industrial wastewater. The present research displays a simple and facile co-precipitation method for the synthesis pure Co-Al LDH and its composite with graphene oxide (GO). A series of composites of GO and Co-Al layered doubled hydroxide with varied content of GO is successfully synthesized that enhanced the photocatalytic performance of Co-Al LDH in terms of MB dye degradation. With the optimized sample, 0.5 g GO loading onto Co-Al LDH termed as 0.5-CAL/GO, the MB dye degradation of 71 % was achieved under white LED light (10 W) irradiation. Synthesized photocatalysts are characterized by several analytical techniques such as (XRD, SEM, FTIR, Raman, UV Visible DRS, Photoluminescence spectroscopy). This research presents the flexible strategy for effective removal of MB dye simulated wastewater, acting as a textile industry wastewater employing a visible light active photocatalyst under white light (LED) illumination. [ABSTRACT FROM AUTHOR]

In this study, unique WO 3 -based bifunctional electrodes were prepared with the aim of achieving optimal photocatalytic and electrocatalytic activities of WO 3 nanoplatelets and Pt nanoparticles, respectively. WO 3 nanoplatelets with a high visible light response were directly grown on both sides of a tungsten substrate via a facile hydrothermal method. Pt nanoparticles were deposited on one side of the WO 3 electrode, where they served as the electrocatalyst. The prepared electrodes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron dispersive X-ray spectroscopy (EDS) and cyclic voltammetry. Our experimental results revealed that the synthesized WO 3 electrodes possessed high photochemical activity under visible light exposure, whereas the deposition of Pt nanoparticles with a large electrochemical active surface area significantly enhanced the electrocatalytic activity of the electrode. Various sets of photodegradation reactions involving Rhodamine B (RhB) were conducted to evaluate the efficacy of the WO 3 electrodes, prior to and following the deposition of Pt nanoparticles under both visible light and applied potential. The bifunctional electrode exhibited far greater activity as compared to the WO 3 electrode as the sole photocatalyst and WO 3 –Pt as the sole electrocatalyst, very promising for energy and environmental applications. [ABSTRACT FROM AUTHOR]

In this study, we investigated the critical factor for promoting visible light photocatalytic hydrogen evolution using a TiO 2 photocatalyst, which limits the amount of Ti 3+ coexisting with the catalyst. Our goal was to establish a simple and cost effective oxidation and anti-oxidation competitive strategy to synthesize a TiO 2-x photocatalyst containing Ti 0 , Ti 2+ , Ti 3+ , and Ti 4+ and an appropriate concentration of Ti 3+ from the oxidation of titanium metal. Finally, the band gap and charge recombination of the final products were successfully optimized by the cooperation of all of the components to achieve efficient visible light photocatalytic hydrogen evolution without the addition of any exogenous dopants, and an ideal quantum yield of approximately 4.28% was achieved at a wavelength of 480 nm. Although various methods have been attempted to preserve Ti 3+ , our strategy for preserving Ti 3+ from the initial preparation to the final products represents a new approach to alter the activity of TiO 2 . [ABSTRACT FROM AUTHOR]

The photocatalytic activity of TiO 2 can be mainly improved from three approaches: (1) enhancing the separation efficiency of photoelectrons and holes, (2) enhancing surface energy, and (3) increasing availability of visible light. Here, we report a one-step method to obtain nitrogen and lanthanum co-doped TiO 2 nanosheets with dominant {0 0 1} facets through a hydrothermal process, using TBOT, triethylamine and LaCl 3 · n H 2 O as precursor and sources of N, La respectively in HF–HNO 3 mixed aqueous solution, and the samples were characterized by XRD, SEM, TEM, XPS, UV-DRS and BET analyses. The XRD and XPS results confirmed that N was doped into the lattice of anatase TiO 2 , while La was not. N acts as an O–Ti–N structure or interstitial N and La exists as LaF 3 in TiO 2 nanosheets. The SEM and TEM results show that the percentage of {0 0 1} facets in the as-synthesized N,La–TiO 2 nanosheets is estimated to be about 75% on average at R F = 1.0. N,La–TiO 2 nanosheets can absorb visible light due to the red shift in the absorption edges, and compared with N–TiO 2 nanosheets, N and La co-doping can further strengthen the absorption of visible light. N,La–TiO 2 nanosheets exhibited higher photocatalytic activity for photodegradation of Rh B under visible light than pure TiO 2 , N–TiO 2 , La–TiO 2 nanosheets and N,La–TiO 2 nanoparticles. N and La co-doping could produce a synergistic effect. The N doping narrowed the band gap of TiO 2 , while the La doping could improve the separation efficiency of photoelectrons and holes. In addition, the La doping could enhance the adsorption property of photocatalyst for organic pollutants. [ABSTRACT FROM AUTHOR]

Two series of morphology-dependent Ag/BiOI composites were successfully synthesized by using a facile photodeposition method. The typical BiOI 2D plate and 3D flower with exposed (001) facets were applied as substrates. The morphology effects of BiOI on the growth of Ag quantum dots and the photocatalytic activity of Ag/BiOI were discussed. During the photodeposition process, weak separation efficiency of BiOI 2D plate facilitated the formation of larger sized Ag quantum dots which displayed higher electron trapping efficiency and resulted in higher photocatalytic activity than those with smaller size on BiOI 3D flower. The pseudo-first-order rate constants k app of BiOI plate and BiOI flower were 0.32 and 0.85 h − 1 while the corresponding activities of Ag/BiOI were further increased 3.25 and 1.11 times for degrading methyl orange. It is a promising way to regulate the activity of Ag/BiOI even the universal noble metal/semiconductor composite through controlling the morphology of semiconductor substrate. [ABSTRACT FROM AUTHOR]

Photocatalytic bismuth tungstate thin films with visible-light activity were deposited via reactive pulsed DC magnetron sputtering onto soda-lime glass substrates. Varying the power delivered to the bismuth and tungsten targets allowed control over the Bi/W ratio in the coatings, and therefore the structural and optical properties of the coatings. As-deposited coatings were characterised with amorphous microstructures and were annealed at 673 K to develop crystallinity. The visible light photocatalytic activity of the coatings, which was analysed using the methylene blue degradation test, was found to be superior to that of a commercial titania-based photocatalytic product. [ABSTRACT FROM AUTHOR]

A facile and effective plasma sputtering method for the preparation of a visible light active photocatalyst - rhombic dodecahedral silver phosphate Ag 3 PO 4 covered with nanographene (Ag 3 PO 4 -GR) with improved stability has been developed. Proposed method allows for the usage of readily available materials for nanographene sputtering and for easy scaling-up. The stability improvement, confirmed by visible light-induced phenol degradation experiment, could be attributed to the synergistic effect of the silver phosphate particles and graphene material allowing for migration of metallic silver nanoparticles from semiconductor's surface to graphene body keeping the semiconductors surface "silver free". Also due to its conductive properties, nanographene may additionally be preventing electron-hole recombination and metallic silver formation. [Display omitted] [ABSTRACT FROM AUTHOR]