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Over the past few years, the elimination of pharmaceuticals from polluted water has been a major challenge for many researchers. The presented project reports the photoelectrochemical (PEC) detection of ciprofloxacin (CIP) by using a BiVO 4 thin layer prepared by a facile spin coat method on an Indium doped tin oxide (ITO) glass as photoanode. The mesoporous nanostructure of the fabricated photoanodes was characterized with UV–vis diffusion transmission spectra, Tauc plot, electrochemical impedance spectroscopy, Mott-Schottky diagram, and chronoamperometry analysis. After optimizing some of the key factors affecting current response of the photoanode, the PEC detection results showed that the BiVO 4 thin-layer photoanode had high and stable photocurrent responses for CIP under UV-Vis light irradiation. Furthermore, the fabricated PEC sensor displayed two wide-spreading linear detection ranges from 0.05 to 100 nM and 100–5700 nM with very low detection limits (LOD) of 0.016 nM. Furthermore, the interferences evaluation demonstrated excellent selectivity of the PEC sensor toward CIP molecules in the presence of other interfering species in solution. Therefore, the marked performance of this photoelectrode in the PEC detection of CIP, extraordinary stability, and admirable reproducibility suggests its potential as a photoanode for the pharmaceutical pollutant oxidation including various antibiotics in wastewater. • Synthesized BiVO 4 material exhibited excellent PEC activity. • ITO/BiVO 4 was successfully applied for the PEC sensing of CIP residues. • This PEC sensor presented excellent performance than another PEC sensor. • The application of sensor was studied in athlete's biological samples. [ABSTRACT FROM AUTHOR]

The novel semiconductor photocatalytic material bismuth vanadate (BiVO4) is gaining significant attention in research due to its unique characteristics, which include a low band gap, good responsiveness to visible light, and non-toxic nature. However, intrinsic constraints such as poor photogenerated charge transfer, slow water oxidation kinetics, and fast electron–hole pair recombination limit the photocatalytic activity of BiVO4. Building heterojunctions has shown to be an effective strategy for enhancing charge separation and impeding electron–hole pair recombination over the last few decades. This review covers the state-of-the-art developments in heterojunction nanomaterials based on BiVO4 for photocatalysis. It explores heterojunction design, clarifies reaction mechanisms, and highlights the current developments in applications including photocatalytic water splitting and organic matter degradation. Finally, it offers a preview of the development paths and opportunities for BiVO4-based heterojunction nanomaterials in the future. This comprehensive assessment of BiVO4-based heterojunctions provides insightful knowledge to researchers in materials science, chemistry, and environmental engineering that will drive advances and breakthroughs in these important fields. [ABSTRACT FROM AUTHOR]

The development of an ideal photoanode that exhibits broad light absorption, efficient photogenerated carrier separation, and superior transmission efficiency remains a pivotal challenge in enhancing the sluggish photoelectrochemical (PEC) water splitting reaction. Here, we present an efficacious strategy to bolster the PEC performance of oxygen evolution by fabricating a BiVO 4 /BiOBr heterojunction through a combined electrochemical deposition-calcination approach and the successive ionic layer adsorption and reaction (SILAR) method. The band structure of BiOBr is optimally aligned with BiVO 4 , enabling the heterojunction to significantly enhance the separation efficiency of photogenerated charges and accelerate the kinetics of PEC water oxidation. Under simulated sunlight irradiation, the BiVO 4 /BiOBr heterojunction exhibits a remarkable photocurrent density of 2.69 mA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE), surpassing the performance of bare BiVO 4 film (0.46 mA/cm2 at 1.23 V vs. RHE) and demonstrating exceptional stability. This work offers novel insights into the rational design and fabrication of solar-driven PEC water splitting photoanodes. [Display omitted] • A type-II heterojunction was constructed between BiVO 4 and BiOBr. • Heterojunction promotes the transmission of photogenerated charge in and on the surface of photoanode bulk phase. • Heterojunction improves the optical absorption range and enhances the photogenerated charge separation. [ABSTRACT FROM AUTHOR]

BiVO4 has been widely concerned due to its great potential in photoelectrochemical (PEC) water splitting. However, low carrier mobilities and high recombination efficiency of photogenerated carriers impede its photocatalytic performance. Herein, an in situ PEC cyclic‐voltammetry‐induced surface reconstruction of BiVO4 photoanodes (BVO pristine) is developed with significantly enhanced efficiency for solar water splitting. A series of in situ characterizations (including in situ X‐ray diffraction, in situ Raman), together with electrochemical tests and density‐functional theory calculations, reveal that during the photoelectrical activation process, the BVO pristine surfaces undergo a crystal plane reconstruction with greatly increased {040} crystal face to promote the separation of photogenerated carriers. In addition, abundant vanadium vacancies and oxygen vacancies are also introduced into the BiVO4 surface during the crystal face reconstruction process with more favorable surface water adsorption and increased injection efficiency of photogenerated carriers. Therefore, the charge‐transfer resistance (Rct) between BVO pristine and electrolyte under AM 1.5G illumination substantially reduced from the original 15 200 to 2820 Ω after the activation. Moreover, the photocurrent density of activated BVO pristines increases more than 12 times, relative to the original BiVO4. In this work, a new horizon for in situ photoelectric activation of semiconductor photoelectrodes with significantly enhanced PEC water splitting is provided. [ABSTRACT FROM AUTHOR]

The construction of semiconductor heterojunctions is an effective strategy to improve the photocatalytic degradation efficiency of organic pollutants. Herein, ZnPc/BiVO4 Z-scheme heterojunction was synthesized via a physical mixing method and was used for the photocatalytic degradation of tetracycline (TC) under visible light irradiation. Compared with BiVO4 and ZnPc, the 15ZnPc/BiVO4 sample exhibited improved light absorption capacity, and the electron-hole separation efficiency and redox capacity were enhanced due to the formation of the Z-scheme heterojunction. The 15ZnPc/BiVO4 composite exhibited an optimal TC degradation rate of 83.1% within 120 min. Additionally, 15ZnPc/BiVO4 exhibited excellent stability in cycling experiments, which maintained a high TC degradation rate of 79.5% after four cycles. Free radical trapping experiments indicated that superoxide radicals (·O2−) were the main active substances in the photocatalytic degradation of TC. [ABSTRACT FROM AUTHOR]

In this paper, FTO conductive glass was used as a substrate to successfully prepare Co3 O4 thin films with controlled morphology by hydrothermal method. Using the prepared Co3 O4 thin films as the base, Co3 O4 @ BiVO4 composite thin films with varying amounts of BiVO4 were successfully prepared by controlling the number of spin-coating cycles. The phase composition and microstructure were analyzed using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). Additionally, their optical absorption and photoelectric properties were measured using a UV-3600 UV-Vis spectrophotometer and an electrochemical workstation. Results indicate that, based on the XRD patterns of the Co3 O4 @ BiVO4 composite thin films, the composite materials were successfully prepared. From the FESEM images, it can be observed that the prepared Co3 O4 @ BiVO4 composite thin films possess a continuous, uniform, and dense surface, with the Co3 O4 thin films growing uniformly as nanowires, and the spin-coated BiVO4 uniformly coating the surfaces of Co3 O4 nanowires in a block-like manner. The optical absorption spectrum reveals enhanced light absorption of the Co3 O4 @ BiVO4 composite thin films compared to pure Co3 O4 thin films. Under zero bias voltage and illumination, the photoelectrical performance of the Co3 O4 @ BiVO4 composite thin films surpasses that of pure Co3 O4 thin films. Electrochemical test results demonstrate that the Co3 O4 @ BiVO4 -3 composite thin films, which were spun-coated three times, showing optimal photoelectrical performance, with a maximum photocurrent approximately 18.4 times that of pure Co3 O4 thin films. The responsivity of the device is 105. 5 μA/W, with a detectivity of up to 1. 988 ×1011 Jones. [ABSTRACT FROM AUTHOR]

We report a detailed study about the correlation between the physicochemical properties of solvothermally synthesized pristine and 1 %, 2.5 %, and 5 % Cu, Mo, and W-doped bismuth vanadate (BiVO 4 , BVO) with its phase composition. The effect of the dopant and the duration of synthesis (8 h and 20 h) on the physicochemical properties of BVO allowed us to tune the ratio of monoclinic scheelite to tetragonal zircon phase in BVO powders. This approach helped us to establish the relationship between the presence of monoclinic scheelite or tetragonal zircon phase with structural, morphological and optical properties of BVO powders, obtained by different physicochemical methods (e.g. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Diffuse Reflectance Spectroscopy (DRS) and Photoluminescence spectroscopy (PL)). The results indicated that, in addition to XRD, Raman, and DRS, several other methods could distinguish between the two phases. For example, SEM analysis revealed that monoclinic scheelite BVO exhibits either elongated assemblies of cube-like particles or prismatic particles with sizes ∼500 nm. In contrast, tetragonal zircon BVO exclusively exhibited porous spherical particles with diameter ∼2 μm. DRS and Raman spectroscopy indicated that there is a possibility of distinguishing between the two phases if their shares are large enough. For instance, monoclinic BVO showed band gap values in the range of 2.35–2.52 eV, while tetragonal zircon BVO exhibited values in the range of 2.80–3.00 eV. XPS showed a correlation between phase composition and surface chemistry of BVO only for Cu-doped samples, revealing the presence of Cu+ in monoclinic BVO and the presence of both Cu+ and Cu2+ in tetragonal zircon BVO. PL showed that monoclinic scheelite BVO displayed decreased charge recombination compared to tetragonal zircon BVO. Deeper insight into the correlation between the physicochemical properties and phase composition of Cu, Mo, and W-doped bismuth vanadate (BiVO 4 , BVO) was based on water/pentanol medium (2:1 vol%) as a novel synthesis pathway. This may open new avenues for the broader methodological exploration of surface chemistry, particle size, and morphology of BVO particles through the use of diverse functionalization agents. Finally, the established links between phase composition and structural, morphological, and other physicochemical properties provide new and more predictable opportunities for further improvement of BVO properties for various applications. [Display omitted] • Numerous characterization methods elucidate BiVO 4 structure-property relationship • Solvothermal synthesis in water-pentanol offers novel pathways for BiVO 4 engineering • Our study surpasses literature by detailing BiVO 4 synthesis and characterization • Experimental parameters govern the formation of BiVO 4 phases with distinct properties • Identified correlations provide a predictable route to enhance BiVO 4 properties [ABSTRACT FROM AUTHOR]

Bismuth vanadate (BVO) ranks among the most promising photoanodes for photoelectrochemical (PEC) water splitting. Nonetheless, slow charge separation and transport, besides the sluggish water oxidation kinetics, are key barriers to its photoefficiency. Here, we present a co‐doping strategy that significantly improves the charge separation performance of BVO photoanodes. We found that, under standard one sun illumination, the Fe−N co‐doped BVO photoanode (Fe−N−BVO) by N‐coordinated Fe precursor reaches a record photocurrent density of 7.01 mA cm−2 at 1.23 V vs RHE after modified a surface co‐catalyst (FeNiOOH), and exhibits an outstanding stability. By contrast, much lower photocurrent density is obtained for the N‐doped, Fe‐doped and Fe/N‐doped BVO photoanode with separated N and Fe precursors. The detailed experimental characterizations show that the high activity of the Fe−N co‐doped BVO photoanode is attributed to the enhanced photo‐induced bulk charge separation, as well as the accelerated surface water oxidation kinetics. XPS, EXAFS and DFT calculations clearly show that, instead of formation of deep trapping state in the individually doped BVO, the co‐doping of Fe−N into BVO generates Fe‐based electronic states just below the bottom of conduction band and N‐derived states just above the top of valence band. Such modulations in electronic structure enable the efficient trap of the electrons and holes to enhance the separation of photo‐induced carriers, but hinder the charge recombination originated from the deep trapping sites. [ABSTRACT FROM AUTHOR]

BiVO4 is one of the most promising candidates for photoelectrochemical water oxidation. However, the poor crystallinity and short hole diffusion length limit its charge separation. One bottleneck stems from the contradiction between high crystallinity and small particles via conventional furnace heating processes. This paper describes the design and fabrication of BiVO4 photoanodes via rapid thermal process (RTP), rather than furnace heating, to decouple the constraints between nucleation, crystallization, and growth processes of BiVO4. The higher heating ramp rate of RTP compared with furnace heating promotes the fast diffusion of reactant molecules, which elevates the nucleation rate above the particle growth rate of BiVO4, leading to small particles with high crystallinity. Moreover, the ultra‐high heating temperature makes it possible to crystallize the small BiVO4 particle within a short time. Thus, a high crystallinity can be obtained for the RTP‐treated BiVO4 while maintaining small particle size, achieving a charge separation efficiency of up to 82%, 30% higher than that of furnace‐treated BiVO4 photoanode. [ABSTRACT FROM AUTHOR]

Green hydrogen (H2) production from solar water splitting necessitates photoelectrodes with superior photoelectrochemical (PEC) activity and durability. However, surface defects and photocorrosion instability—especially at high potentials—limit PEC performance and stability. Herein, the prototypical bismuth vanadate (BiVO4) photoanode is used to demonstrate a holistic approach to improve photocurrent density and long‐term stability. In this approach, high surface‐area nanostructuring of BiVO4 is combined with barium (Ba) doping with semi‐crystalline hafnium oxide (HfO2) surface passivation and single‐atom nickel platinum (NiPt) catalysts. The introduction of Ba2+ ions into BiVO4 increases the concentration of conductive V4+ ions or the ratio of V4+ ions to oxygen vacancies, avoiding V5+ dissolution during water oxidation. The semi‐crystalline HfO2, which serves as a passivation layer, prevents BiVO4 photocorrosion by suppressing harmful chemical reactions when holes are transferred to the electrolyte. The synergistic use of isolated single‐atom and Ni‐Pt coordination improves charge transfer at the photoanode/electrolyte interface, leading to enhanced PEC kinetics and stability. As a result, a photoelectrode is demonstrated with ≈6.5 mA cm−2 at 1.23 V versus a reversible hydrogen electrode (RHE) and continuous operation for 800 h with a negligible degradation rate. This work provides a promising approach to improve photoanodes for PEC H2 production. [ABSTRACT FROM AUTHOR]

BiVO4 has garnered substantial interest as a promising photoanode material for photoelectrochemical water‐splitting due to its narrow band gap and appropriate band edge positions for water oxidation. Nevertheless, its practical use has been impeded by poor charge transport and sluggish water oxidation kinetics. Here, a hybrid composite photoanode is fabricated by uniformly embedding SnS2 nanoparticles near the surface of a BiVO4 thin film, creating a type II heterostructure with strong interactions between the nanoparticles and the film for efficient charge separation. This structure forms via eutectic melting during atomic layer deposition of SnS2 with subsequent phase separation between SnS2 and BiVO4 at room temperature, offering greater advantages and flexibilities over conventional exsolution techniques. Furthermore, the SnS2/BiVO4 hybrid composite is coated with a thin amorphous ZnS passivation layer to accelerate charge transfer process and enhance long‐term stability. The optimized BiVO4/SnS2/ZnS photoanode exhibits a photocurrent density of 5.44 mA cm−2 at 1.23 V versus RHE, which is 2.73 times higher than that of the BiVO4 photoanode, and a dramatic improvement in photostability retention at 1.23 V versus RHE, increasing from 55% to 91% over 24 hours. This method of anchoring nanoparticles onto host materials proves highly valuable for energy and environmental applications. [ABSTRACT FROM AUTHOR]

A BiVO4/Fe2O3 heterojunction for non-enzymatic photoelectrochemical (PEC) determination of hydrogen sulfide (H2S) is reported. The BiVO4/Fe2O3 heterojunction promoted the separation of photo-generated carriers, reduced electron–hole recombination, and thus improved electron collection and photocurrent. The proposed BiVO4/Fe2O3/FTO sensor exhibited a linear range of 1–500 μM and a detection limit of 0.51 nM H2S. In addition, high selectivity, good reproducibility, and stability were obtained for H2S sensing. The detection of H2S in water and serum samples demonstrated its feasibility. This work provides a new strategy to detect and understand the bio-function of H2S in the biological environment. [ABSTRACT FROM AUTHOR]

A novel methodology to obtain 3D printable BiVO 4 precursor scaffolds (3DM-BiVO 4) via robocasting, showing excellent periodicity, shape retention, and mechanical stability, is disclosed for the first time. The ceramic pastes (solids at 70 wt.-%) comprised of BiVO 4 precursor, SiO 2 NPs, and a solution of deionized water: ethylene glycol (volume ratio 1:2, DI water: EG) exhibited enhanced rheology for the 3D printing of self-supported structures (3DM-BiVO 4). The thermal treatment induced a monoclinic scheelite phase, and the ethylene glycol contributed to achieving a unique square flake-like particle morphology. 3DM-BiVO 4 scaffolds were used as reusable monolithic photocatalysts, showing 72% acetaminophen mineralization at 240 min and pH = 9. This innovative approach opens avenues for designing 3D printable ceramic pastes, offering potential applications in tailoring-made monolithic photocatalyst fabrication by using SiO 2 NPs as an inorganic binder. [Display omitted] • 3D printable BiVO4 pastes by DIW using SiO2NP as a ceramic binder and DI water:ethylene glycol as solvents. • 3DM-BiVO4 scaffolds with periodicity, excellent shape retention, mechanical stability, and self-supporting were achieved. • Ethylene glycol promotes morphologies of square flake-like particles comprised of small peanut-like BiVO4 particles. • 3DM-BiVO4 exhibited good photocatalytic activity for acetaminophen mineralization. • 3DM-BiVO4 photocatalyst can be easily recovered and reused several times. [ABSTRACT FROM AUTHOR]

In this work, the surface of BiVO4 nanoporous films was modified by ultrathin CoOx nanoparticles through a facile electrochemical deposition route. By adjusting the deposition time, the effect of CoOx loading amount (or time) was investigated with respect to the photoelectrochemical (PEC) performance of the BiVO4 photoanode. No significant morphological changes were observed after depositing CoOx cocatalysts onto the BiVO4 surface, except for a rougher surface and the appearance of nanosheets at 40 s. After optimizing the deposition time, the highest photocurrent density of 3.36 mA/cm2 was achieved at 1.23 VRHE for the 20-CB sample under solar irradiation, exhibiting a nearly threefold increase in the photocurrent as compared to that of pristine BiVO4 (1.24 mA/cm2). It was found that the CoOx loading reduced the onset potential and interfacial charge transfer resistance, leading to the significant enhancement of the PEC activity. However, when the deposition time was extended or the loading amount increased, the PEC activity actually decreased, which might be related to the increase in carrier recombination loss. This research will help us understand the mechanism of surface CoOx modification for improving the PEC activity of semiconductor photoanodes like BiVO4. [ABSTRACT FROM AUTHOR]

The generation of oxygen vacancies and Bi-metal on BiVO 4 enhances conductivity, extending both catalytic activity and cyclability in Li–O 2 batteries. [Display omitted] Bismuth Vanadate (BiVO 4) is a promising oxide-based photoanode for electrochemical applications, yet its practical use is constrained by poor charge transport properties, particularly under dark conditions. This study introduces a novel BiVO 4 variant (Bi-BiVO 4 -10) that incorporates abundant oxygen vacancies and in-situ formed Bi metal, significantly enhancing its electrical conductivity and catalytic performance. Bi-BiVO 4 -10 demonstrates superior electrochemical performances compared to conventional BiVO 4 (C-BiVO 4), demonstrated by its most positive half-wave potential with the highest diffusion-limiting current in the oxygen reduction reaction (ORR) and earliest onset potential in the oxygen evolution reaction (OER). Notably, Bi-BiVO 4 -10 is explored for the first time as an electrocatalyst for lithium-oxygen (Li–O 2) cells, showing reduced overcharge (610 mV) in the first cycle and extended cycle life (1050 h), outperforming carbon (320 h) and C-BiVO 4 (450 h) references. The enhancement is attributed to the synergy of oxygen vacancies, Bi metal formation, increased surface area, and improved electrical conductivity, which collectively facilitate Li 2 O 2 growth, enhance charge transport kinetics, and ensure stable cycling. Theoretical calculations reveal enhanced chemical interactions between intermediate molecules and the defect-rich surfaces of Bi-BiVO 4 -10, promoting efficient discharge and charge processes in Li–O 2 batteries. This research highlights the potential of unconventional BiVO 4 -based materials as durable electrocatalysts and for broader electrochemical applications. [ABSTRACT FROM AUTHOR]

Bismuth-based semiconductor materials have garnered significant attention because of their appropriate optical bandgap and substantial photoelectric conversion efficiency. Enhancing the photocurrent and fill factor of photovoltaic films is essential for developing high-performance optoelectronic devices. In this study, high-performance BiVO 4 -ZnTiO 3 multilayer films were fabricated using a straightforward sol-gel method, where the incorporation of ZnTiO 3 films significantly improved the photovoltaic performance of BiVO 4. Through structural design aimed at enhancing light utilization, the BiVO 4 -ZnTiO 3 multilayer film achieved a photocurrent density of 1.9 mA/cm2 at 450 nm, along with a fill factor of 46.8 % in the composite multilayer structure. The improvement in film performance is attributed to the overall multilayer stacking effect. This study offers a novel approach for utilizing bismuth-based semiconductors in optoelectronics. [ABSTRACT FROM AUTHOR]

Globally, the emergence of drug-resistant bacteria has created an urgent need for an effective method to remove antibiotics from pharmaceutical wastewater. Engineering Bismuth vanadate (BiVO4) with an oxygen evolution cocatalyst (OEC) holds a promising potential for enhancing water splitting efficiency in the production of hydrogen (H2) using free solar energy. Here, we successfully developed a Zr:BiVO4/NiFeOOH heterojunction by electrodeposition and photoelectrochemical transformation. Zr:BiVO4/NiFeOOH photoanodes exhibit 5 fold superior photocurrent response at 1.23 V compared with Zr:BiVO4 electrodes, since NiFeOOH acts as an oxygen-releasing catalyst. Furthermore, the attained heterojunctioned electrode can effectively degrade TCH, riboflavin, and streptomycin in PEC. The degradation rate of TCH acquired 96% within 1 h, which is 3 times superior than the efficiency reported for pristine Zr:BiVO4 photoelectrodes. By introducing NiFeOOH into BiVO4, electron life-time was increased and electron-hole recombination was suppressed. In this study, we present a solar-driven, sustainable and effective way of treating wastewater and provide new insights into the process.

[Display omitted] To reveal the mechanism of charge transfer between interfaces of BiVO 4 -based heterogeneous materials in photoelectrochemical water splitting system, the cocatalyst was grown in situ using tannic acid (TA) as a ligand and Fe and Co ions as metal centers (TAFC), and then uniformly and ultra-thinly coated on BiVO 4 to form photoanodes. The results show that the BiVO 4 /TAFC achieves a superior photocurrent density (4.97 mA cm−2 at 1.23 V RHE). The charge separation and charge injection efficiencies were also significantly higher, 82.0 % and 78.9 %, respectively. From XPS, UPS, KPFM, and density functional theory calculations, Ligand-to-metal charge transfer (LMCT) acts as an electron transport highway in TAFC ultrathin layer to promote the concentration of electrons towards metal center, leading to an increase in the work function, which enhances the built-in electric field and further improves the charge transport. This study demonstrated that the LMCT pathway on TA-metal complexes enhances the built-in electric field in BiVO 4 / TAFC to promote charge transport and thus enhance water oxidation, providing a new understanding of the performance improvement mechanism for the surface-modified composite photoanodes. [ABSTRACT FROM AUTHOR]

Crystal facet‐dependent photogenerated charge transfer at the semiconductor/current collector interface of photoelectrodes is equally important compared to that at the semiconductor/liquid interface for efficient photoelectrochemical (PEC) water splitting, which, however, is difficult to explore due to the rigid solid/solid interface in conventional photoelectrodes. Here, the facet‐dependent charge transfer at both semiconductor/liquid and semiconductor/collector interfaces in liquid metal‐embraced photoelectrodes is systematically investigated using faceted BiVO4 micro‐particles with different ratios of {110} and {010} facets as model materials. The results from the photo(electro)chemical and photophysical characterizations reveal that {010} facets outperform {110} facets at the semiconductor/liquid interface in triggering water oxidation due to the lower valence band maximum (VBM) of {010} facets, while {110} facets are more efficient at the semiconductor/metal interface for the collection of photogenerated electrons due to their higher conduction band minimum (CBM). Consequently, the photoelectrodes of liquid metal‐embraced BiVO4 particles exposing 53% {110} facets yield the best PEC performance for water splitting due to the well‐balanced photogenerated charge transfer at the interfaces of semiconductor/metal and semiconductor/liquid. [ABSTRACT FROM AUTHOR]

BiVO4 is an important n-type semiconductor used in photocatalysis due to its high capacity to absorb solar light in the 400–700 nm range, abundance, high chemical stability, non-toxicity, and low cost. However, research on physicochemical modifications to increase its catalytic activity via simple procedures is limited. In this work, the influence of different synthesis parameters, such as calcination temperatures or silver doping, on the structural and physicochemical characteristic of the BiVO4-based photocatalysts and their photocatalytic performance in degrading sulfamethoxazole from aqueous solution under blue-LED irradiation was evaluated. BiVO4-based photocatalysts were synthesized using a solvothermal method. The monoclinic phase (m-s) was successfully kept stable even after the thermal treatments at 300, 450, and 600 °C and the corresponding silver doping. The low bandgap of 2.40 eV and the average particle size of 18 nm of the BiVO4 catalyst treated at 300 °C seems to be the key. Afte doping, Ag/BiVO4 photocatalyst treated at the optimal found calcination temperature (300 °C) showed the best photocatalytic behavior. [ABSTRACT FROM AUTHOR]

Manipulating the catalyst body and surface photogenerated charge separation is significant in expanding research in the field of photoelectrochemical water splitting. This paper introduces a certain amount of Bi-vacancies at the BiVO4 photoanode by in-situ photoreduction and makes rational use of polarization field engineering to promote the separation of surface photogenerated carriers. Focusing on comparing the photoelectrochemistry (PEC) performance of BiVO4 with different concentrations of Bi-vacancies under piezoelectric polarization field. At 1.23 V vs. RHE, the photocurrent density of the best sample is 0.147 mA/cm2, which is 1.8 times higher than that of BiVO4. In addition, the photocurrent density reached 0.162 mA/cm2 under ultrasonic conditions. The presence of a moderate amount of Bi-vacancies provides a large number of active sites, which lowers the potential barrier for redox reactions thereby reducing the resistance to electron leaps, decreasing the forbidden bandwidth and increasing the light absorption range. The piezoelectric polarization field is triggered by ultrasonic conditions, and the cavitation bubbles are ruptured by ultrasonic vibrations, generating a large amount of charge involved in the water splitting reaction. The presence of surface vacancies makes the piezoelectric polarization easier to be triggered, and the enhanced built-in piezoelectric field acts as a driving force to improve the interfacial separation and transport efficiency of photogenerated carriers, which effectively improves the PEC performance. This work provides a new and scientifically sound idea for the combined use of vacancy defect engineering and piezoelectric effect in the field of PEC splitting water. [ABSTRACT FROM AUTHOR]

We synthesized BiVO4 mesocrystals with ordered assembly structure, and studied the structural order and the relationship between the photodegradation of Rhodamine B. Au nanoparticles (NPs) were successfully loaded onto Meso-BiVO4 by light-assisted induction, and Cd nanoparticles were further selected to be deposited on Au nanoparticles to form Z-scheme photocatalyst Meso-BiVO4-Au-CdS heterostructures. We try and propose to analyze its ordered assembly structure by XRD for the first time. The results show that Meso-BiVO4 is a mesocrystal with highly exposed (001) plane and directional assembly structure. The charge separation efficiency of all samples was studied by PL spectroscopy. The results show that the Z-scheme Meso-BiVO4-Au-CdS can promote the charge separation and obtain the best carrier separation efficiency. Thus, it has the best photocatalytic activity in the experiment of photocatalytic degradation of rhodamine B. The main active species in the degradation process were confirmed by free radical trapping experiment, and the degradation mechanism was put forward. [ABSTRACT FROM AUTHOR]

Energy demand worldwide demands clean, cheap, and renewable energy. Through the use of photoelectrochemical (PEC) conversion, solar energy can be transformed into chemical energy. Bismuth vanadate (BiVO4), a material exhibiting visible light activity, favourable conduction band edge energies, and ease of synthesis, has become increasingly popular in recent years. In BiVO4, charge carriers recombine rapidly, which adversely affects the PEC performance and stability. There have been several strategies developed to mitigate these deficiencies, including novel heterojunctions, doping with metals, coupling with cocatalysts, interface modification and modifying morphology. To achieve the best results, it is required to develop PEC devices with exceptional cost‐to‐efficiency ratios and long‐term durability. This review also examines novel yet commercially viable applications for BiVO4‐based photoanodes. Lastly, we discuss the challenges and perspectives facing PEC water splitting systems based on BiVO4. [ABSTRACT FROM AUTHOR]

Globally, the emergence of drug-resistant bacteria has created an urgent need for an effective method to remove antibiotics from pharmaceutical wastewater. Engineering Bismuth vanadate (BiVO 4) with an oxygen evolution cocatalyst (OEC) holds a promising potential for enhancing water splitting efficiency in the production of hydrogen (H 2) using free solar energy. Here, we successfully developed a Zr:BiVO 4 /NiFeOOH heterojunction by electrodeposition and photoelectrochemical transformation. Zr:BiVO 4 /NiFeOOH photoanodes exhibit 5 fold superior photocurrent response at 1.23 V compared with Zr:BiVO 4 electrodes, since NiFeOOH acts as an oxygen-releasing catalyst. Furthermore, the attained heterojunctioned electrode can effectively degrade TCH, riboflavin, and streptomycin in PEC. The degradation rate of TCH acquired 96% within 1 h, which is 3 times superior than the efficiency reported for pristine Zr:BiVO 4 photoelectrodes. By introducing NiFeOOH into BiVO 4 , electron life-time was increased and electron-hole recombination was suppressed. In this study, we present a solar-driven, sustainable and effective way of treating wastewater and provide new insights into the process. [Display omitted] • Synthesis of Zr:BiVO 4 /NiFeOOH photoanodes via photoelectrochemical transformation process. • Synergistic effect of NiFeOOH co-catalytic layer over Zr:BiVO 4 electrodes with enriched PEC performances. • A photocurrent of 1.27 mA/cm2 with nearly 5-fold enhancement is achieved. • The electrodes demonstrated superior performance in the degradation of tetracycline hydrochloride using PEC. [ABSTRACT FROM AUTHOR]

The application of BiVO4 in photoelectrochemical water splitting for efficient clean hydrogen energy production encounters challenges arising from the sluggish kinetics of water oxidation. Motivated by the synergistic interplay of metal sites and ligands on the catalyst surface, we utilized the photoelectric deposition technique to introduce amorphous nanothin layers of cobalt–iron double hydroxide (referred to as CoFe-LDH) onto the Fe-doped BiVO4 surface. Fe dopants lead to a size reduction of BiVO4 nanoparticles while enlarging the specific surface area and pore volume, thus increasing the reaction sites, which is favorable for photoelectrochemical water splitting. The unique dual-layered structure of CoFe-LDH not only enhances the mobility of charge carriers but also addresses surface defects through passivation. Additionally, it optimizes the exposure of active sites on the surface and expedites the flow of charge carriers, effectively mitigating recombination. The CoFe/Fe-BiVO4 photoanode demonstrates outstanding photocatalytic performance, achieving a substantial photocurrent of 2.56 mA cm–2 (at 1.23 V vs RHE) and an impressive incident photon current conversion efficiency (IPCE) of 52.1% at 400 nm, which is approximately a 270% increment in photocurrent and a remarkable 2.2-fold improvement in IPCE compared to those of the unmodified sample. In addition, the charge surface transport efficiency increases from 16.8% to 62.5% at 1.23 V vs RHE after modification of the cobalt–iron hydroxide bilayer. This study not only emphasizes the promising results of employing binary polymetallic co-catalysts but also provides a strategic pathway to improve semiconductor-based photoelectrodes in various photoelectrochemical applications. [ABSTRACT FROM AUTHOR]

Bismuth vanadate (BiVO4) has long been considered a promising photoanode material for photoelectrochemical (PEC) water splitting. Despite its potential, significant challenges such as slow surface water evolution reaction (OER) kinetics, poor carrier mobility, and rapid charge recombination limit its application. To address these issues, a triadic photoanode has been fabricated by sequentially depositing CdS nanoparticles and NiFe-layered double hydroxide (NiFe-LDH) nanosheets onto BiVO4, creating a NiFe-LDH/CdS/BiVO4 composite. This newly engineered photoanode demonstrates a photocurrent density of 3.1 mA cm−2 at 1.23 V vs. RHE in 0.1 M KOH under AM 1.5 G illumination, outperforming the singular BiVO4 photoanode by a factor of 5.8 and the binary CdS/BiVO4 and NiFe-LDH/BiVO4 photoanodes by factors of 4.9 and 4.3, respectively. Furthermore, it exhibits significantly higher applied bias photon-to-current efficiency (ABPE) and incident photon-to-current efficiency (ICPE) compared to pristine BiVO4 and its binary counterparts. This enhancement in PEC performance is ascribed to the formation of a CdS/BiVO4 heterojunction and the presence of a NiFe-LDH OER co-catalyst, which synergistically facilitate charge separation and transfer efficiencies. The findings suggest that dual modification of BiVO4 with CdS and NiFe-LDH is a promising approach to enhance the efficiency of photoanodes for PEC water splitting. [ABSTRACT FROM AUTHOR]

[Display omitted] The photoelectrochemical (PEC) performance of BiVO 4 is limited by sluggish water oxidation kinetics and severe carrier recombination. Herein, a novel high-performance BiVO 4 /NiFe-NOAQ photoanode is prepared by a simple one-step hydrothermal method, using BiVO 4 and 1-Nitroanthraquinone (NOAQ) as raw materials. The BiVO 4 /NiFe-NOAQ photoanode has an excellent photocurrent density of 5.675 mA cm−2 at 1.23 V RHE , which is 3.35 times higher than that of the pure BiVO 4 (1.693 mA cm−2) photoanode. The BiVO 4 /NiFe-NOAQ shows a significant improvement in charge separation efficiency (86.12 %) and charge injection efficiency (87.86 %). The improvement is ascribable to the NiFe-NOAQ form a type II heterojunction with BiVO 4 to inhibit carrier recombination. More importantly, the kinetic isotope experiment suggests that the proton-coupled electron transfer (PCET) process can enhance the charge transfer of BiVO 4 /NiFe-NOAQ. The contact angle measurements show that modifying functional groups enhanced the hydrophilicity of BiVO 4 /NiFe-NOAQ, which can further accelerate the PCET process. The XPS and PL results as well as the tauc plot indicate that the strong electron-withdrawing ability of –NO 2 which can promote the extension of π conjugation, results in more π electron delocalization and produces more efficient active sites, thus achieving efficient photoelectrochemical water oxidation. [ABSTRACT FROM AUTHOR]

Bismuth vanadate (BiVO4) has emerged as a highly prospective material for photoanodes in photoelectrochemical (PEC) water oxidation. However, current limitations with this material lie in the difficulties in producing stable and continuous BiVO4 layers with efficient carrier transfer kinetics, thereby impeding its widespread application in water splitting processes. This study introduces an accessible fabrication approach that yields continuous, monoclinic nanostructured BiVO4 films, paving the way for their use as photoanodes in efficient PEC water oxidation for hydrogen production under solar light conditions. The fabrication involves the intercalation of vanadium (V) ions into Bi2O3 films at 450 °C. Upon interaction with V ions, the film undergoes a transformation from tetragonal Bi2O3 to monoclinic scheelite BiVO4. This synthesis method enables the fabrication of single monoclinic phase BiVO4 films with thicknesses up to 270 nm. The engineered monoclinic BiVO4 film, devoid of any pinholes that could cause carrier loss, exhibits a robust photocurrent of 1.0 mA/cm2 at 1.23 VRHE in a neutral electrolyte, without requiring additional modifications or doping. Moreover, we demonstrate that the incorporation of a cobalt phosphate (Co–Pi) cocatalyst into the BiVO4 photoanode significantly enhances the lifetime of photogenerated holes by a factor of 9, resulting in a further elevation of the photocurrent to 2.9 mA/cm2. This remarkable PEC enhancement can be attributed to the surface state passivation by the Co–Pi cocatalyst. Our fabrication approach opens up a facile route for producing large-scale, highly efficient BiVO4 photoanodes for PEC water splitting technology. [ABSTRACT FROM AUTHOR]

Mo-doped BiVO4 (Mo-BiVO4) nanoparticle-based photoanodes were fabricated using an electrodeposition–calcination method to investigate the influence of Mo doping on the surface states (SS) for the photoelectrocatalytic degradation performance of chloramphenicol (CAP) in water. The characterization results show that the prepared samples were nanostructured BiVO4. Mo doping with a low concentration has a negligible effect on the surface nanomorphology, crystal structure, and light absorption characteristics. CAP as an efficient organic scavenger can undergo degradation via the photoelectron trapping/detrapping process of the V5+/V4+ redox system under illumination. The photoelectron trapping process of V5+ to V4+ exhibited an increase and then a decrease with increasing Mo doping concentrations. The introduction of suitable Mo into the BiVO4 can tune the photoelectron trapping process to form the surface states for adsorbing CAP (SSCAP). Furthermore, Mo doping produces more oxygen vacancies (Vo) on the electrode surface, which are in favor of trapping photogenerated holes, thereby promoting the charge transfer efficiency at the semiconductor–electrolyte interface (SEI). These multiple effects process the highest charge transfer efficiency (reaching 96%) for CAP degradation when the Mo doping content is 1.07 wt %. This work gives a further understanding of the enhancement of photoelectrocatalytic degradation performance caused by Mo doping in the field of charge transfer at SEI. [ABSTRACT FROM AUTHOR]

Cocatalysts play a key role in enhancing activity of photoelectrodes while the study of their interaction remains a challenge. Here, we decoupled the relationship between oxygen evolution reaction (OER) performance and photoelectrochemical (PEC) water oxidation performance by modifying an identical BiVO4 with different cobalt‐based OER catalysts including Co, CoO, Co3O4, and Co4N. The electrochemical OER activities of these cobalt specimens were quite similar. Their anodic photocurrent density followed an order of: Co4N>Co>Co3O4>CoO after loading on the BiVO4 electrode. The kinetics process and energy band diagram were analyzed, revealing that the interface between different cobalt specimens and BiVO4 electrode influenced the charge recombination and transfer. Accordingly, we propose a corresponding structural model, which shows that the cocatalysts consist of inner part for interface modulation and the outer layer for catalysis. The present work reveals the vital role of contact interface between cocatalysts and semiconductors, and more attention should be paid when selecting the cocatalysts. [ABSTRACT FROM AUTHOR]

As the system with the highest solar hydrogen conversion efficiency, the further improvement of photovoltaic-photoelectrocatalysis (PV-PEC) efficiency is dependent on the light transmittance, activity and stability of the photoanode. Here, a highly permeable BiVO 4 thin film was fabricated through controlled magnetron sputtering. The thickness of the thin film was merely 345 nm, while its transmittance in the visible light range reached as high as 70%. Moreover, large-scale production of such films could be achieved. By incorporating NiFeO x oxygen extraction cocatalyst, under AM 1.5G illumination, the photocurrent density at 1.23 V on reversible hydrogen electrode (RHE) increased to 4.2 mA cm−2 and the incident photon-current conversion efficiency reached 70%. A PV-PEC system was designed to efficiently harness sunlight by integrating the photoanode with a solar photovoltaic panel. Upon connection with the solar photovoltaic panel (with an efficiency of only 7%), spontaneous water decomposition could be achieved, resulting in a solar-to-hydrogen conversion efficiency (η STH) of 4.2% for the series system. This study contributes to the realization of cost-effective and highly efficient PV-PEC hydrogen production. The PV-PEC series system with BiVO 4 thin film photoanode prepared by magnetron sputtering method improves the overall utilization rate of sunlight and realizes spontaneous water decomposition. [Display omitted] • BiVO 4 films with large area and high transmittance can be prepared by low rate controlled magnetron sputtering. • The PEC performance of films was improved by optimizing the magnetron sputtering process and supporting catalyst. • Photovoltaic and photoanode in PV-PEC cells can be irradiated in series to improve the utilization rate of sunlight. [ABSTRACT FROM AUTHOR]

Because of its advantageous band gap and band edge, BiVO 4 is thought to be a viable photoanode for photoelectrochemical (PEC) water splitting. However, its photoelectrochemical water splitting capability is primarily restricted by photogenerated carrier recombination. In order to address this issue, a hole storage layer (HSL) VO 2 was deposited onto a W-doped BiVO 4 photoanode through photoelectric deposition in this study. During PEC water oxidation, the ultrathin VO 2 layer's reversible V4+ species can regulate the hole-storage process, improving hole extraction capacity and reducing charge recombination. As expected, under AM 1.5 G illumination, the optimized W–BiVO 4 /VO 2 /Co-Pi photoanode exhibits a photocurrent density of 5.6 mA/cm2 at 1.23 V vs. RHE with an onset potential of 0.28 V. This value exceeds pure BiVO 4 (1.1 mA/cm2) by around 409%. Based on results from experiments, the charge transfer efficiency of the W–BiVO 4 /VO 2 /Co-Pi photoanode reaches 96.3%, showing excellent PEC water splitting performance. • Preparation of VO 2 particles on BiVO 4 photoanodes by photoelectric deposition for the first time. • Cyclic voltammetry demonstrates that V4+ redox in VO 2 significantly enhances hole stroage and transfer. • W–BiVO 4 /VO 2 exhibits a leading 1.54% ABPE value, showing its superiority among HSL-modified photoanodes. • The W–BiVO 4 /VO 2 /Co-Pi photoelectrode's current density was 5.6 mA cm−2 at 1.23 V vs. RHE. [ABSTRACT FROM AUTHOR]

In this paper, the electronic structures, optical properties and photocatalytic performances of Mo doped into V-site of BiVO4 with different concentrations were investigated using the first nature principles based on density generalized function theory. The results of the defect formation energy calculations indicate that all three doping systems of BiMoxV1-xO4（x=0.0625, 0.125, 0.25） are stable.The electronic structure calculations show that the band gaps of the four systems of BiMoxV1-xO4（x=0, 0.0625, 0.125, 0.25） are 2.123 eV, 2.142 eV, 2.160 eV and 2.213 eV, respectively. The band gap values of the doped BiVO4 system are all larger than that of the intrinsic BiVO4, and the band gap increases with the increase of Mo concentration.The energy band structures of the three doped systems BiMoxV1-xO4（x=0.0625, 0.125, 0.25） are all shifted to the lower energy region, resulting in the doped system conduction band bottom crossing the Fermi energy level, and Mo doped BiVO4 has n-type semiconductor properties.Optical property calculations show that dielectric constants of the intrinsic BiVO4 and three doped systems BiMoxV1-xO4（x=0.0625,0.125,0.25） are 3.08, 3.90, 12.7 and 17.50, respectively, and the static dielectric constants show an increasing trend after doping. The reflection coefficients and the imaginary parts of the dielectric functions for the three doped BiVO4 systems are significantly enhanced in the low-energy region, and the light absorption coefficients of three Mo-doped BiVO4 systems are significantly enhanced for infrared light. The photocatalytic performance calculations showed that the intrinsic BiVO4 oxidation of H2O to O2is the weakest and the BiMo0.25V0.75O4 oxidation of H2O to O2 is the strongest. [ABSTRACT FROM AUTHOR]

Slow oxygen evolution kinetics and severe corrosion limit the further application of BiVO4 photoelectrodes in photoelectrochemical water splitting. Here, BiVO4/Co-Pi/Ni(OH)2 photoanodes were synthetized with the aim of improving their photoelectric conversion efficiency and stability. Compared with a pure BiVO4 photoanode, the BiVO4/Co-Pi/Ni(OH)2 photoanode enhanced the photocurrent from 1.1 to 4.5 mA/cm² at 1.23 V versus the reversible hydrogen electrode. In addition, Ni(OH)2 acted as a corrosion protection layer on the surface of the photoanode, allowing the BiVO4/Co-Pi/Ni(OH)2 photoanode to exhibit excellent stability. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) water splitting presents a promising approach for harnessing solar energy and converting it into hydrogen energy. However, the limited water oxidation activity of semiconductor photoanodes has severely hampered the overall conversion efficiency. In this study, a hollow dodecahedral structure of NiCo-LDH (HD-NiCo-LDH) was designed using the metal-organic framework ZIF-67 as a precursor. HD-NiCo-LDH was employed to modify the BiVO4 photoanode, serving as an oxygen evolution cocatalyst. HD-NiCo-LDH can enhance light absorption, accelerate photogenic hole extraction, promote photogenic charge separation and improve the kinetics of water oxidation reaction. Significantly, the unique hollow dodecahedral structure of HD-NiCo-LDH possesses a larger specific surface areas, which provides additional active sites for the water oxidation reaction and facilitates the adsorption of water molecules. The photocurrent density of the optimized HD-NiCo-LDH/BiVO4 photoanode reaches 4.54 mA/cm2 at 1.23 V vs. RHE, which is 3.3 times greater than the bare BiVO4 photoanode. This presented work introduces an innovative design concept for photoanodes supported by oxygen evolution cocatalysts with multi-active sites.

The present article reports a novel approach for synthesizing two-dimensional (2D) lattice-engineered layered titanate–bismuth vanadate (NS-titanate–BiVO4) nanohybrid thin films by a combination of electrophoretic deposition (EPD) and chemical solution growth (CSG) methods. The synthesized nanohybrid thin films display significant absorption of visible light and depressed electron–hole recombination, demonstrating the strong electronic coupling between the hybridized species. Upon hybridization, the chemical stability of pristine BiVO4 is significantly enhanced due to the highly stable NS-titanate. The hybridization of NS-titanate with BiVO4 leads to the formation of highly mesoporous house-of-cards-type morphology beneficial for improved photocatalytic activity. The resultant nanohybrids are very effective for visible-light-driven photocatalytic degradation of dyes (methylene blue (MB), rhodamine-B (Rh-B)) and tetracycline hydrochloride (TC) antibiotic with photodegradation rates of 85.1, 97, and 73%, respectively, higher than that of pristine BiVO4 which is one of the most prominent visible-light-active photocatalysts. Present results underscore the superior photofunctionality of the NS-titanate–BiVO4 nanohybrids as an effective visible-light-driven photocatalyst. Moreover, these findings vividly demonstrate that NS-titanate-based nanohybrids are quite effective in enhancing photocatalytic activity and developing various types of 2D nanosheet-based hybrid materials. [ABSTRACT FROM AUTHOR]

Bismuth vanadate (BiVO4) is reported as a key material in photoelectrocatalysis owing to high theoretical efficiency, relatively narrow band gap of 2.4 eV, and favorable conduction band edge position for hydrogen evolution. However, the sluggish hole transport dynamics lead to slow photogenerated charge separation and transport efficiencies, which result in charge recombination due to aggregation. Herein, a novel hole transport layer of copper(I) thiocyanate (CuSCN) with the aim of significantly enhancing the efficiency of charge transport and stability of BiVO4 photoanodes is reported. The introduction of the hole transport layer could provide an appropriate intermediate energy level for photogenerated hole transfer and avoid charge recombination and trapping. After a photoassisted electrodeposition process of NiCoFe‐Bi catalysis, the obtained photoanode achieves a photocurrent density of 5.6 mA cm−2 at 1.23 V versus reversible hydrogen electrode under AM 1.5 G simulated solar radiation, and an applied bias photon to current efficiency of 2.31%. With the CuSCN layer, BiVO4 photoanode presented impressive stable photocurrent during 50 h continuous illumination. Meanwhile, the unbiased tandem device of the NiCoFe‐Bi/CuSCN/BiVO4 photoanode and the Si solar cell exhibit a solar‐to‐hydrogen efficiency of 5.75% and excellent stability for 14 h. [ABSTRACT FROM AUTHOR]

The highly insulated solid discharge products in sodium‐oxygen (Na−O2) batteries induce large polarization and thus heavily threaten their cycle life. Controlment of discharge products taking efficient catalyst is a best way to solve this problem. Here, Mo‐doped BiVO4 as the catalyst produces large amounts of carrier, thus boosting the battery reaction and reducing the overpotential under the light assistance. Compared with the BiVO4 without Mo doping, the doped one has a lower recombination of photogenerated carriers, thus benefiting a large polarization suppression and Na−O2 batteries running for over 270 cycles under 3.65 V as well as a fine rate performance. Besides, Mo doping reduces the size of BiVO4, beneficial for the carrier transportation and more reactions due to the large specific surface area. Experiment combined with theoretical calculation shows that Mo doping is advantageous to enhancing catalytic activity of BiVO4 due to a lower work function for easier electron extraction, thus enhancing Na2O2 decomposition capability. This work undoubtedly inspires photocatalysts′ use for solving the insulated solid discharge products decomposition in metal‐O2 batteries and provides a guide for other photocatalysts possibilities. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) fuel cells that enable organic pollutants degradation while generating H2 are regarded as a viable approach in addressing global energy and environmental issues. Herein, an efficient PEC fuel cell is constructed using oxygen vacancy-rich BiVO4 (O[sub V]:BiVO4) as the photoanode and triethanolamine (TEOA) pollutant as the fuel. Under AM 1.5 G, this OV:BiVO4-TEOA PEC fuel cell shows an ultra-high photo-driven current density of 20.40 mA cm--2 at 1.23 V versus reversible hydrogen electrode, which is superior to most reported PEC fuel cells. The Faradic efficiency of H[sub 2] production is about 97.26%, and no CO2 is released in the anode chamber due to the strong CO2 adsorption by excess TEOA. Further integration of a Pt/C cocatalyst coated Si photocathode in the O[sub V]:BiVO4-TEOA PEC fuel cell can achieve bias-free H2 production with a current density of 10.17 mA cm--2. The experimental and theoretical calculation results reveal the importance of the robust complexation between the O[sub V]:BiVO[sub 4] photoanode and TEOA, which ensures thorough conversion of chemical energy in TEOA and high activity of the PEC fuel cell. This work will guide the design of efficient PEC fuel cells for simultaneous pollutant treatment and H2 production. [ABSTRACT FROM AUTHOR]

BiVO 4 photoanode shows severe recombination of photogenerated carriers, which limits its water oxidation performance for photoelectrochemical (PEC) water splitting. In this paper, the surface of BiVO 4 photoanode was modified through the coupling of phosphotungstic acid (H 3 O 40 PW 12 ·xH 2 O, denotes as PWO) with CoOOH to address such drawbacks. At 1.23 V RHE , the photocurrent density of BiVO 4 /PWO/CoOOH photoanode reaches 2.80 mA/cm2, which is 2.59-fold that of bare BiVO 4 photoanode. Moreover, the initial onset potential of BiVO 4 /PWO/CoOOH photoanode is also negatively decreased by 270 mV than that of bare BiVO 4 photoanode. Detailed structural and electrochemical characterizations demonstrate that the decoration of PWO serves as an intermediate layer to promote the transport of holes from BiVO 4 to CoOOH, while the deposition of CoOOH acts as a protective layer as well as cocatalyst to reduce the photocorrosion and improve the PEC activities of BiVO 4. The synergistic coupling of PWO and CoOOH not only makes efficient bulk and surface charge separation, but also takes full advantage of photo-generated holes on the surface, which accelerates water oxidation kinetics, ultimately achieving an improvement in PEC water oxidation. PWO and CoOOH, which widens the range of light absorption and effectively enhances the capacity of light absorption, can therefore induce BiVO 4 to produce more photogenerated charge. Meanwhile, CoOOH facilitates the kinetics of water oxidation. The synergistic effect of PWO and CoOOH improves the PEC performance of BiVO 4. [Display omitted] • BiVO 4 /PWO/CoOOH composite photoanode is reasonably designed and synthesized. • BiVO 4 /PWO/CoOOH photoanode shows excellent stability for PEC. • BiVO 4 /PWO/CoOOH electrode exhibited a high PCD of 2.8 mA/cm2 at 1.23 V RHE. • Synergistic effects of PWO and CoOOH deposition improved the performance. [ABSTRACT FROM AUTHOR]

In this study, we unveil a groundbreaking approach, incorporating dopants and engineering heterojunctions, to craft an exceptional g-C 3 N 4 /ThO 2 @BiVO 4 photoanode through a two-step process of methanolic dispersion spin-coating followed by electrodeposition (ED) method. The PEC cells utilizing the g-C 3 N 4 /ThO 2 @BiVO 4 heterojunction photoanode outperform both the g-C 3 N 4 /BiVO 4 and standalone BiVO 4 , with the g-C 3 N 4 /ThO 2 @BiVO 4 achieving a notably enhanced photocurrent density of 0.45 mA cm−2 at 1.23 V vs. RHE. This signifies a substantial improvement over the photocurrent densities of 0.32 mA cm−2 and 0.21 mA cm−2 attained by the g-C 3 N 4 /BiVO 4 and BiVO 4 photoanodes, respectively. Exhibiting a distinctive dual-nanostructure morphology, the deposited g-C 3 N 4 /ThO 2 @BiVO 4 photoelectrode constructs a 'spongy' and 'needle-like' nanoflower architecture, ultimately converging into a densely packed agglomerate. The incorporation of Oxygen and about 5.8% Th4+- doping not only induces noteworthy photostability but also amplifies charge transfer efficiency while concurrently mitigating charge recombination within the g-C 3 N 4 /ThO 2 @BiVO 4 photoanode, achieved through the creation of defects, as elucidated in XPS and Raman analyses. Our in-depth exploration highlights the exceptional performance and photostability of the g-C 3 N 4 /ThO 2 @BiVO 4 photoanode, establishing it as an auspicious candidate for applications in photoelectrochemical (PEC) water splitting. • The g-C 3 N 4 /ThO 2 @BiVO 4 photoanode was successfully undergo through doping and engineering heterojunctions. • The Th4+ and O− modified g-C 3 N 4 /ThO 2 @BiVO 4 , altering elemental composition by doping oxygen atom in XPS analysis. • The g-C 3 N 4 /ThO 2 @BiVO 4 photoelectrode displays dual-nanostructure with 'spongy' and 'needle-like' nanoflower morphology. • PL analysis revealed g-C 3 N 4 /ThO 2 @BiVO 4 photoanode with significantly reduced energetic separation in electron-hole pairs. • The g-C 3 N 4 /ThO 2 @BiVO 4 photoanode achieved over 200% increase, reaching ∼0.21 mA cm−2 to 0.45 mA cm−2 at 1.23 vs. RHE. [ABSTRACT FROM AUTHOR]

The solid-state route, conducted at a temperature of 700 °C over a span of 8 h, resulted in the production of a single phase of BiVO 4 powder. Subsequently, the BiVO 4 powder was used as a tribocatalyst to facilitate the degradation of the methylene blue (MB) dye, Rhodomine B (RB), and tetracycline pollutant. The confirmation of phase formation was achieved by employing X-ray diffraction and Raman spectroscopy techniques. The synthesised BiVO 4 powder was utilized as a tribocatalyst, where the maximum degradation for MB dye, RB dye, and tetracycline was observed to be ∼69 %, ∼74 %, and ∼49 in 24 h in a glass-PTFE interface system. The present work provides a systematic representation of the effect of speed (in rpm) in the tribocatalysis process. The findings derived from the scavenger test reveal that the mechanism of tribocatalysis in the degradation of MB dye is influenced by the presence of superoxide radicals (• O 2 −), which serve as the primary active species. [ABSTRACT FROM AUTHOR]

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Copyright of Iron Steel Vanadium Titanium is the property of Iron Steel Vanadium Titanium Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, we investigated the effects of H2O2 addition on OH radical formation on the surfaces of visible-light-irradiated BiVO4–TiO2 nanocomposite photocatalysts. Additionally, we examined the possible roles of OH radicals formed by the reduction reaction of H2O2 on the visible-light-irradiated surfaces of photocatalytic BiVO4–TiO2 nanocomposites. The BiVO4–TiO2 nanocomposite photocatalysts were prepared by mixing a BiVO4 photocatalytic film with commercially available semiconductor particulate TiO2 photocatalysts. By removing oxygen gas from the photocatalytic reactor, the effects of oxygen molecules on OH radical formation during the visible-light irradiation of BiVO4–TiO2 nanocomposite photocatalysts were examined. During visible-light irradiation, BiVO4 and BiVO4–TiO2 photocatalysts play different roles in OH radical formation because of two characteristic reduction reaction channels: (a) the direct reduction of H2O2 on photocatalytic surfaces and (b) the indirect reduction reaction of H2O2 by superoxide radical anions (O2−). [ABSTRACT FROM AUTHOR]

In this study, we investigated the effects of H2O2 addition on OH radical formation on the surfaces of visible-light-irradiated BiVO4–TiO2 nanocomposite photocatalysts. Additionally, we examined the possible roles of OH radicals formed by the reduction reaction of H2O2 on the visible-light-irradiated surfaces of photocatalytic BiVO4–TiO2 nanocomposites. The BiVO4–TiO2 nanocomposite photocatalysts were prepared by mixing a BiVO4 photocatalytic film with commercially available semiconductor particulate TiO2 photocatalysts. By removing oxygen gas from the photocatalytic reactor, the effects of oxygen molecules on OH radical formation during the visible-light irradiation of BiVO4–TiO2 nanocomposite photocatalysts were examined. During visible-light irradiation, BiVO4 and BiVO4–TiO2 photocatalysts play different roles in OH radical formation because of two characteristic reduction reaction channels: (a) the direct reduction of H2O2 on photocatalytic surfaces and (b) the indirect reduction reaction of H2O2 by superoxide radical anions (O2−).