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BiVO4 faces significant challenges for widespread application in photoelectrochemical (PEC) water oxidation due to its poor hole transport ability, high surface defect density, and sluggish water oxidation reaction kinetics. Employing interfacial engineering to assist in energy level modulation is an effective strategy to address these challenges. Herein, a CuCrO2 hole transport layer (HTL) is coupled and further grew NiCo‐MOF in situ to prepare a NiCo‐MOF‐CuCrO2‐BiVO4 composite photoanode. The novel composite photoanode not only achieves a photocurrent density of 5.75 mA cm−2 at 1.23 V versus a reversible hydrogen electrode (vs RHE) but also maintains stable operation for over 24 h. Comprehensive physicochemical characterization and density‐functional theory calculations confirm that the built‐in electric field generated by the p–n heterojunction formed between the CuCrO2 HTL and BiVO4 photoanode enhances the hole transport ability. Moreover, the NiCo‐MOF chelated on the photoanode surface not only passivates the surface defect states but also accelerates the kinetics of the water oxidation reaction. Under the synergistic effect of dual modification, the PEC water oxidation performance of the BiVO4 photoanode is dramatically improved. This pioneering work presents a MOF/HTL/BiVO4 configuration that provides a blueprint for the future development of integrated photoanodes for efficient solar energy conversion. [ABSTRACT FROM AUTHOR]

Herein, we propose a simple and effective fluoride (F−) ions post‐treatment method to improve the solar water splitting performance of monoclinic BiVO4 (abbreviated as BVO). The surface modification of BVO with functional F− ions not only facilitates the transfer and separation efficiency of carriers at the electrode/electrolyte interface but also promotes the adsorption and activation of water, resulting in a photocurrent of 3.2 mA/cm2 at a bias voltage of 1.2 VRHE. Furthermore, the transfer and separation of carriers in the bulk and on the surface are further regulated by the oxygen vacancies induced by F− ions, thereby enhancing the PEC water splitting performance of BVO. Notably, the experimental findings demonstrate that the introduce of F− ions into the KBi electrolyte enhances the photo‐charging process of BVO. Specifically, at a bias voltage of 0.6 VRHE, the BVO‐0.12F sample exhibits a stable photocurrent of 1.2 mA/cm2, which is twice as high as that of the initial BVO sample. Remarkably, our study unveils that the addition of F− ions into the KBi electrolyte solution plays a pivotal role in facilitating the separation of charge carriers and promoting interfacial charge transport. Consequently, this further leads to a substantial enhancement in the solar water splitting performance for BVO‐0.12F photoanode. [ABSTRACT FROM AUTHOR]

Bismuth vanadate (BVO) with a small band gap and suitable band edges is regarded as one of the promising photocatalysts for water oxidation. However, the short charge-transfer path limits its photocatalytic performance. Establishing a heterojunction and incorporating a co-catalyst are feasible methods to improve the photocatalytic ability of BVO by enhancing carrier transfer rates and reducing in-electrode resistances. In this study, nickel tellurium oxide (NTO) and cobalt iron Prussian blue analogues (CoFePBA) are incorporated into the BVO electrode to respectively develop a heterojunction and decorate co-catalyst for efficiently catalyzing the water oxidation reaction for the first time. Different amounts of CoFePBA are deposited on the NTO/BVO electrode by varying the electrodeposition durations to enhance exited charge generations and maintain high absorbance of incident light. The largest photocurrent density of 6.55 mA/cm2 at 1.23 V versus reversible hydrogen electrode is attained for the optimal CoFePBA/NTO/BVO electrode prepared using an electrodeposition duration of 2 min. Excellent catalytic stability is also achieved, with the photocurrent retention of 91.9% after illuminating the electrode for 5000 s. This study provides blueprints for incorporating novel electrochemically active materials in the BVO system to realize heterojunction and co-catalyst strategies, thereby attaining excellent photocatalytic ability toward water oxidation. [Display omitted] • Ni–Te oxide (NTO) and Co–Fe Prussian blue analogue (CoFePBA) combined in BiVO 4 (BVO). • Heterojunction and co-catalyst are made for catalyzing water oxidation efficiently. • Different CoFePBA amount is deposited on NTO/BVO by varying electrodeposition times. • A photocurrent density of 6.55 mA/cm2 at 1.23 V RHE is obtained for CoFePBA/NTO/BVO. • Excellent stability is achieved with a photocurrent retention of 91.9% after 5000 s. [ABSTRACT FROM AUTHOR]

Constructing a catalyst capable of reducing CO2 through photoreduction in aqueous environments presents a significant challenge. In this study, we present the synthesis of BiVO4@NiCo2O3 heterojunction using a straightforward hydrothermal method for CO2 photoreduction. The sample with the optimal loading ratio demonstrates a CO generation rate of 7.202 μmol ⋅ g−1 ⋅ h−1, which is twice that of pure BiVO4 (3.626 μmol ⋅ g−1 ⋅ h−1) and 1.5 times that of pure NiCo2O3 (4.726 μmol ⋅ g−1 ⋅ h−1). Analysis using XPS and EPR techniques suggests that electron transfer at the interface of the heterojunction facilitates the separation of photogenerated charge carriers, thereby enhancing the efficiency of the photocatalytic process. This investigation offers a viable approach for developing photocatalysts for CO2 reduction in aqueous environments. [ABSTRACT FROM AUTHOR]

In photocatalytic studies, tetragonal bismuth vanadate (t-BiVO4) is not promising due to its wide band gap. However, according to previous studies, the tetragonal phase is inevitable when the monoclinic bismuth vanadate (m-BiVO4) is modified. Therefore, it is necessary to find ways to improve the photoresponse and photocatalytic ability of t-BiVO4 under visible light. In this study, Yb3+ and Tm3+ co-doped BiVO4 was synthesized by a simple hydrothermal method, and its microstructure, morphology and optical properties were characterized and analyzed by scanning electron microscope, transmission electron microscopy, Brunauer-Emmett-Teller, X-ray diffraction, Raman, X-ray photoelectron spectroscopy, diffuse reflectance spectra, photoluminescence, upconversion luminescence and other means. The results show that BiVO4:Yb3+/Tm3+ (BVYT) has a high content of tetragonal phase (about 80%), showing the characteristics of t-BiVO4. BVYT shows a higher separation efficiency of photogenerated carriers, its transient photocurrent response intensity increased by about 3 times, and the photocatalytic efficiency is significantly improved compare with the undoped m-BiVO4. Under simulated sunlight, BVYT completely degraded methylene blue (MB) solution and rhodamine B solution in 45 and 90 min, respectively, and the reaction rate was significantly improved. BVYT also shows excellent photocatalytic ability under visible light, about 35% of MB solution was degraded within 45 min under visible light irradiation (> 420 nm), this is because Yb3+ effectively promotes the upconversion luminescence of Tm3+ in response to visible light, and the energy cycle mechanism of Yb-Tm-Tm is proposed. Consequently, BiVO4 with high content of tetragonal phase has excellent photoactivity, even exceeding m-BiVO4. This is a novel discovery in the field of photocatalysis, which provides a broader application prospect for BiVO4 in photocatalysis. [ABSTRACT FROM AUTHOR]

Surface engineering of BiVO4 photoanodes is effective and feasible for photoelectrochemical (PEC) water splitting. To achieve superior PEC performance, however, more than one surface engineering method is usually indispensable, for which a positive synergistic effect is vital and thus highly desired. Herein, it is reported that the incorporation of borate moieties into ultrathin p‐type NiOx catalysts can induce the reconfiguration of surface catalytic sites to form new highly active species, in addition to enhanced fast charge separation and transfer. The photocurrent density of BiVO4 photoanodes is enhanced from 1.49 to 5.76 mA cm−2 at 1.23 V versus reversible hydrogen electrode (RHE) under AM 1.5G illumination, which is achieved by successive modifications of NiOx and borate moieties. It is found that BO3 groups anchored to Ni atoms by replacing the surface hydroxyl sites of NiOx catalysts not only increase the relative ratio of Ni3+ species to facilitate charge transfer but also provide efficient active sites for H2O molecule adsorption and oxidation reactions. This work demonstrates the positive synergistic effect of these two surface engineering methods and provides an effective pathway to construct highly efficient and stable photoanodes for PEC water splitting. [ABSTRACT FROM AUTHOR]

Photoelectrochemical solar to hydrogen production is a promising way to achieve carbon neutrality, but severe charge recombination in photoanodes limits the conversion efficiency. Herein, Au nanoparticles and Co(OH)x co‐sensitized bismuth vanadate (BiVO4) to construct AuCo(OH)x/BiVO4 photoanode for significantly enhancing the performance of photoelectrochemical water splitting. This process significantly improves the bulk charge carrier separation efficiency, the surface kinetics of water oxidation, and the electron density of BiVO4 photoanode through Au surface plasmon resonance (SPR) and Co(OH)x oxygen evolution catalysts effect. Additionally, the enhancement of the *O and the *OOH generation accelerate the oxygen evolution reaction kinetics. Consequently, the constructed AuCo(OH)x/BiVO4 photoanode demonstrates an excellent photocurrent of 6.2 mA cm−2 at 1.23 V versus reversible hydrogen electrode and a stable continuous output within 42 h. This work contributes to developing high‐efficiency and high‐stability photoanodes for solar H2 production through SPR effect and oxygen evolution catalysts. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) water splitting is a promising technology for green hydrogen production. However, severe charge recombination in the photoelectrode materials is one of the key obstacles to achieving high performance. Herein, a BiVO₄ photoanode with lattice strain (Str‐BVO) is constructed by generating Bi vacancies to promote charge separation in the bulk. The optimized Str‐BVO photoanode achieves a photocurrent density of 6.20 mA cm⁻2 at 1.23 V versus the reversible hydrogen electrode under AM 1.5 G illumination, with an impressive charge separation efficiency close to 100%. Systematical experiments and density functional theory reveal that the surface Bi vacancies induced strain causes the distortion of a small number of VO4 tetrahedra, which increases the antibonding state energy of most normal VO4 tetrahedra and creates more electronic vacancy states, thereby significantly promoting electron–hole separation. By surface loading with a FeNiOx co‐catalyst, the photoanode exhibits excellent PEC water‐splitting performance and stability. [ABSTRACT FROM AUTHOR]

Recently, tungsten oxide (WO 3) and bismuth vanadate (BiVO 4) have been considered as an intriguing combination for constructing a heterojunction for efficient photoelectrochemical (PEC) applications. Herein, we report the preparation of ternary WO 3 /BiVO 4 /NiCo layered double hydroxide (LDH) photoanodes for boosting photogenerated carrier transport and promotion of catalytic activity. WO 3 /BiVO 4 heterostructures were synthesized by a hydrothermal process of WO 3 nanoplates on a fluorine-doped tin oxide (FTO) glass substrate, followed by spin-coating for BiVO 4 materials. We investigated the effect of a NiCo LDH catalyst on PEC performance by controlling the growth temperatures of the NiCo LDH via hydrothermal synthesis. Moreover, the X-ray diffraction (XRD), Fourier‒transform infrared (FTIR) and X‒ray photoelectron spectroscopy (XPS) analyses revealed that the WO 3 /BiVO 4 heterojunction was retained after the NiCo LDH growth process regardless of synthesis temperatures. The PEC results verified that the WO 3 /BiVO 4 heterostructure with the optimized NiCo LDH catalyst (WBN60) possessed the best photocurrent density of 3.2 mA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE), which created improved charge separation and surface oxidation kinetics of photogenerated carriers. Consequentially, the smallest charge transfer resistance and recombination rate were achieved in the WBN60 electrode compared to others, indicating a much lower photoelectrode‒electrolyte interfacial resistance and the enhancement of photogenerated carrier transport by suppressing recombination. [ABSTRACT FROM AUTHOR]

An economically viable solution-based approach was employed for fabrication of nanostructured BiVO4. The evolution of physiochemical and electrochemical features with respect to the synthesis temperature was analyzed using structural, morphological, and electrochemical analysis. When utilized as a supercapacitor electrode, in 3-electrode setup, the BiVO4 exhibited highly impressive specific capacity of 1864 Cg−1 at a high current density with battery type behavior. Also, this attractive material exhibits very lesser charge transfer resistance of 4 Ω, which is highly beneficial for performing charge/discharge at higher current rates. Further, this material retained 84% of its initial capacity after 3000 repeated charge discharge cycles. The behavior of the same electrode material can be either battery-like or pseudocapacitive, depending on its shape, size, and intercalation ion. Although it can be challenging to draw a precise border, the range of b values between 0.5 and 1.0 denotes a "transition" area between pseudocapacitive and battery-type materials. It is important to note that when the reaction temperature rises from 140 °C to 160 °C, 180 °C, and 200 °C, more electroactive sites emerge, leading to improved electrochemical performance. The battery type behavior is dominated as the reaction temperature is increased from 140 °C, and it is consistent with the voltagram analysis. [ABSTRACT FROM AUTHOR]

The thermal transformation of the tetragonal‐zircon (tz‐) to tetragonal‐scheelite (ts‐)BiVO4 was studied by in situ synchrotron X‐ray diffraction, thermogravimetric analysis, and Fourier‐transformed infrared spectroscopy. Upon heating, the tetragonal zircon polymorph of BiVO4 (tz‐BiVO4) transitioned to the ts‐polymorph between 693–773 K. Above 773 K, single phase ts‐BiVO4 was observed before transitioning to the monoclinic fergusonite (mf‐) polymorph upon cooling. An anomaly in thermal expansion was observed between 400–500 K, associated with the loss of intercalated H2O/NH4+ from the coprecipitation procedure. Heating tz‐BiVO4 resulted in contraction of the V−O bond distance and VO4 polyhedra volume, ascribed to rotation of the tetrahedra groups. Attempts to study this by neutron diffraction failed due to the large incoherent scatter from the hydrogenous species. Efforts to remove these species while maintaining the tz‐BiVO4 structure were unsuccessful, suggesting they play a role in stabilizing the tz‐polymorph. The local structure of both mf‐BiVO4 and tz‐BiVO4 were investigated by X‐ray pair distribution function analysis, revealing local distortions. [ABSTRACT FROM AUTHOR]

[Display omitted] • We prepared BVO@VO with dual-phase heterostructure. • The heterostructure enables rapid de/insertion of Zn2+ ions. • The Zn2+ diffusion rate in BVO@VO exceeds VO 2 by three orders of magnitude. • The BVO@VO presents a capacity retention of 96% after 2000 cycles at 2.0 A g−1. • The obtained all-solid-state pouch cell shows excellent electrochemical performance. Rechargeable aqueous zinc ion batteries (ZIBs) have emerged as a promising alternative to lithium-ion batteries due to their inherent safety, abundant availability, environmental friendliness and cost-effectiveness. However, the cathodes in ZIBs encounter challenges such as structural instability, low capacity, and sluggish kinetics. In this study, we constructed BiVO 4 @VO 2 (BVO@VO) heterojunction cathode material with bismuth vanadate and vanadium dioxide phases for ZIBs, which demonstrate significant advancements in both aqueous and quasi-solid-state ZIBs. Benefitting from the heterojunction structure, the materials present a high capacity of 262 mAh g−1 at 0.1 A g−1, superb cyclic stability with 96% capacity retention after 1000 cycles at 2 A g−1, and outstanding rate property with a specific capacity of 218 mAh g−1 even at a high rate of 5.0 A g−1. Furthermore, the flexible quasi-solid-state ZIBs incorporating the BVO@VO cathode demonstrate prolonged cyclic life performance with a remarkable specific capacity of 234 mAh g−1 over 100 cycles at a current density of 0.1 A g−1. This study potentially paves the way for the utilization of heterointerface-enhanced zinc ion diffusion for vanadium-based materials in ZIBs, thereby providing a new approach for the design and investigation of high-performance zinc-ion systems. [ABSTRACT FROM AUTHOR]

The high voltage required to overcome the thermodynamic threshold and the complicated kinetics of the water splitting reaction limit the efficiency of single semiconductor‐based photoelectrochemistry. A semiconductor/solar cell tandem structure has been theoretically demonstrated as a viable path to achieve an efficient direct transformation of sunlight into chemical energy. However, compact designs exhibiting the indispensable optimally balanced light absorption have not been demonstrated. In the current work, we design and implement a compact tandem providing the complementary absorption of a highly transparent BiVO4 photoanode and a PM6:Y6 solar cell. Such bandgap combination approaches the optimal to reach the solar‐to‐hydrogen (STH) conversion upper limit for tandem photoelectrochemical cells (PECs). We demonstrate that, by using a photonic multilayer structure to adequately balance sunlight absorption among both tandem materials, a 25% increase in the bias‐free STH conversion can be achieved, setting a clear path to take compact tandem PECs to the theoretical limit performance. [ABSTRACT FROM AUTHOR]

Strong metal‐support interaction (SMSI) is widely proposed as a key factor in tuning catalytic performances. Herein, the classical SMSI between Au nanoparticles (NPs) and BiVO4 (BVO) supports (Au/BVO‐SMSI) is discovered and used innovatively for photoelectrochemical (PEC) water splitting. Owing to the SMSI, the electrons transfer from V4+ to Au NPs, leading to the formation of electron‐rich Au species (Auδ−) and strong electronic interaction (i.e. Auδ−‐Ov‐V4+), which readily contributes to extract photogenerated holes and promote charge separation. Benefitted from the SMSI effect, the as‐prepared Au/BVO‐SMSI photoanode exhibits a superior photocurrent density of 6.25 mA cm−2 at 1.23 V versus the reversible hydrogen electrode after the deposition of FeOOH/NiOOH cocatalysts. This work provides a pioneering view for extending SMSI effect to bimetal oxide supports for PEC water splitting, and guides the interfacial electronic and geometric structure modulation of photoanodes consisting of metal NPs and reducible oxides for improved solar energy conversion efficiency. [ABSTRACT FROM AUTHOR]

The escalation of energy and environmental crises highlights the increasingly critical role of clean energy. In this study, ternary NiCoV layered double hydroxide nanosheets were electrodeposited onto the BiVO4 photoanode using a low bias voltage, enhancing the hole injection efficiency on the BiVO4 surface. The introduction of low-valent V species, serving as effective electron donors, promotes metal species coupling and enhances the catalytic performance. A heterojunction structure, comprising BiVO4 and layered double hydroxides-(LDH) nanosheets, was formed to improve the photoelectrochemical (PEC) water splitting capabilities of the BiVO4 photoanode. The photocurrent density of BiVO4/NiCo-LDH/-0.1 V photoelectrode prepared under low bias voltage is 2.64 mA/cm2, which is 1.27 times that of the BiVO4/NiCo-LDH/-0.7 V photoelectrode (2.08 mA/cm2) and 2.15 times that of bare BiVO4 (1.23 mA/cm2). After introducing the V species, the photocurrent density of BiVO4/NiCoV-LDH prepared under low bias was 3.32 mA/cm2, which is 1.25 times and 1.59 times higher than that of BiVO4/NiCo-LDH/-0.1 V and BiVO4/NiCo-LDH/-0.7 V photoelectrodes, respectively. The surface efficiency (ηsurface) of BiVO4/NiCoV-LDH is 71%, representing a 2.45-fold increase over that of pure BiVO4. The improvement of PEC performance is attributed to the synergistic catalytic effect of V species with Ni and Co species in the NiCoV-LDH nanocatalyst prepared under low bias voltage as well as the unique crystal and amorphous structure that provides more active sites. This study introduces a catalyst for photoelectrochemical water splitting and paves the way for the innovative design of other multimetal hydroxides. [ABSTRACT FROM AUTHOR]

Bismuth vanadate (BiVO4) is a promising photoanode material for efficient photoelectrochemical (PEC) water splitting, whereas its performance is inhibited by detrimental surface states. To solve the problem, herein, a low-cost organic molecule 1,3,5-benzenetricarboxylic acid (BTC) is selected for surface passivation of BiVO4 photoanodes (BVOs), which also provides bonding sites for Co2+ to anchor, resulting in a Co-BTC-BVO photoanode. Owing to its strong coordination with metal ions, BTC not only passivates surface states of BVO, but also provides bonding between BVO and catalytic active sites (Co2+) to form a molecular cocatalyst. Computational study and interfacial charge kinetic investigation reveal that chemical bonding formed at the interface greatly suppresses charge recombination and accelerates charge transfer. The obtained Co-BTC-BVO photoanode exhibits a photocurrent density of 4.82 mA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE) and a low onset potential of 0.22 VRHE under AM 1.5 G illumination, which ranks among the best photoanodes coupled with Co-based cocatalysts. This work presents a novel selection of passivation layers and emphasizes the significance of interfacial chemical bonding for the construction of efficient photoanodes. [ABSTRACT FROM AUTHOR]

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Formaldehyde (HCHO) is one of the primary indoor air pollutants, and efficiently eliminating it, especially at low concentrations, remains challenging. In this study, BiVO4-TiO2 catalyst was developed using ultrasonic blending technology for the photocatalytic oxidation of low-level indoor HCHO. The crystal structure, surface morphology, element distribution, and active oxidation species of the catalyst were examined using XRD, SEM, TEM, UV–Vis, EDS, and ESR techniques. Our results demonstrated that the BiVO4-TiO2 catalyst, prepared by ultrasonic blending, exhibited good oxidation performance and stability. The HCHO concentration reduced from 1.050 to 0.030 mg/m3 within 48 h, achieving a removal rate of 97.1%. The synergy between BiVO4 and TiO2 enhanced the efficiency of separating photogenerated carriers and minimized the likelihood of recombination between photogenerated electrons and holes. Additionally, this synergy significantly enhanced the presence of hydroxyl radicals (·OH) on the catalyst, resulting in an oxidation performance superior to that of either BiVO4 or TiO2. Our research offers valuable insights for the development of new photocatalysts to address HCHO pollution. [ABSTRACT FROM AUTHOR]

In order to expand the application of bismuth vanadate (BiVO4) to the field of photoelectrochemistry, researchers have explored the potential of BiVO4 in catalyzing or degrading organic substances, potentially presenting a green and eco-friendly solution. A study was conducted to investigate the impact of electrolytes on the photocatalysis of benzyl alcohol by BiVO4. The research discovered that, in an acetonitrile electrolyte (pH 9) with sodium bicarbonate, BiVO4 catalyzed benzyl alcohol by introducing saturated V5+. This innovation addressed the issue of benzyl alcohol being susceptible to catalysis in an alkaline setting, as V5+ was prone to dissolution in pH 9 on BiVO4. The concern of the photocorrosion of BiVO4 was mitigated through two approaches. Firstly, the incorporation of a non-aqueous medium inhibited the formation of active material intermediates, reducing the susceptibility of the electrode surface to photocorrosion. Secondly, the presence of saturated V5+ further deterred the leaching of V5+. Concurrently, the production of carbonate radicals by bicarbonate played a vital role in catalyzing benzyl alcohol. The results show that, in this system, BiVO4 has the potential to oxidize benzyl alcohol by photocatalysis. [ABSTRACT FROM AUTHOR]

In this work, a coupling system consisting of bismuth vanadate (BiVO4) and cobalt-based polyoxometalates (Co-POMs) was developed to enhance the oxygen evolution reaction. Crystallization-driven self-assembly and the wet chemical synthesis method were deployed in synthesizing Co-POMs and monoclinic–tetragonal mixed–phase BiVO4, respectively. The introduction of Co-POMs into a BiVO4-containing mixture significantly enhanced the water oxidation reaction, with a more than twofold increment in the total amount of oxygen evolved. For instance, 461.2 µmol of oxygen was evolved from the system containing 20 mg of Co-POMs compared to 195 µmol of oxygen produced from a pristine BiVO4 system. This extraordinary improvement in the oxygen evolution reaction indicates the existence of a positive synergic effect between BiVO4 and Co-POMs, in which Co-POMs could act as effective cocatalysts to extract photogenerated charge carriers generated by BiVO4 and improve the charge transfer process. However, the amount of oxygen produced was slightly reduced to 440.7 µmol with an increase in AgNO3 loading from 30 mg to 60 mg. This unforeseen phenomenon could be elucidated by the shielding effect of silver particles, in which a higher AgNO3 loading led to a more prominent shielding effect. The presence of silver nanoparticles on post-reaction BiVO4 was confirmed by TEM and XPS analysis. This newly established process scheme provides an insight into the development of an efficient photocatalytic oxygen evolution system in realizing future commercial applications toward green energy production. [ABSTRACT FROM AUTHOR]

In this work, poly(vinylidene fluoride) (PVDF)‐bismuth vanadate (Bi4V2O11; BVO)‐sodium dodecyl sulfate (SDS) composite films are fabricated by the solution casting method. The frequency dependence of the dielectric and electric performances of the resultant PVDF‐BVO‐SDS composites on various weight percentages of SDS contents is investigated. The results demonstrate that the three‐component PVDF‐BVO‐SDS composites have a superior dielectric constant (96) and suppressed dielectric loss (<1) at 102 Hz for 20 wt% of SDS contents. The surface morphology of the PVDF‐BVO‐SDS composites shows that SDS is successfully reinforced on the PVDF‐BVO matrix with better homogeneity. The ac conductivity of the PVDF‐BVO‐SDS composites is also improved, which is helpful for the enhancement of the dielectric constant and relatively low loss in the composites. Moreover, the PVDF‐BVO‐SDS composite also exhibits a larger value of the dielectric constant (96) than the pristine PVDF matrix, which is 15 times higher than that of the pristine one. These significantly enhanced dielectric and electrical characteristics of PVDF‐BVO‐SDS composites will fulfill the practical criteria for their use in high dielectric‐constant capacitors and energy storage devices. [ABSTRACT FROM AUTHOR]

BiVO4 is one of the most promising photoanode materials for photoelectrochemical (PEC) solar energy conversion, but it still suffers from poor photocurrent density due to insufficient light‐harvesting efficiency (LHE), weak photogenerated charge separation efficiency (ΦSep), and low water oxidation efficiency (ΦOX). Herein, we tackle these challenges of the BiVO4 photoanodes using systematic engineering, including catalysis engineering, bandgap engineering, and morphology engineering. In particular, we deposit a NiCoOx layer onto the BiVO4 photoanode as the oxygen evolution catalyst to enhance the ΦOX of Fe‐g‐C3N4/BiVO4 for PEC water oxidation, and incorporate Fe‐doped graphite‐phase C3N4 (Fe‐g‐C3N4) into the BiVO4 photoanode to optimize the bandgap and surface areas to subsequently expand the light absorption range of the photoanode from 530 to 690 nm, increase the LHE and ΦSep, and further improve the oxygen evolution reaction activity of the NiCoOx catalytic layer. Consequently, the maximum photocurrent density of the as‐prepared NiCoOx/Fe‐g‐C3N4/BiVO4 is remarkably boosted from 4.6 to 7.4 mA cm−2. This work suggests that the proposed systematic engineering strategy is exceptionally promising for improving LHE, ΦSep, and ΦOX of BiVO4‐based photoanodes, which will substantially benefit the design, preparation, and large‐scale application of next‐generation high‐performance photoanodes. [ABSTRACT FROM AUTHOR]

Photocatalytic degradation of pollutants has been extensively studied. Among the investigated photocatalysts, BiVO4 has emerged as a very promising material. BiVO4 is known for its narrow band‐gap energy suitable for solar‐driven reactions; however, it is subjected to challenges such as charge recombination and slow electron transfer kinetics. Combining BiVO4 with g‐C3N4 proves promising, aligning energy levels and leveraging unique charge transport properties to enhance dye degradation under visible light. This study reports a novel synthesis of g‐C3N4−BiVO4 heterojunction through in‐situ urea pyrolysis, ensuring homogeneous dispersion. While maintaining the monoclinic structure of BiVO4, the heterojunction exhibits increased surface area and a more negative zeta potential, influencing catalyst‐substrate to be degraded interactions. Adsorption studies reveal distinct behaviors with cationic dyes (MB and RhB) forming multilayers, hindering light absorption, and reducing photocatalytic efficiency. Conversely, the heterojunction performs efficiently with the anionic MO dye. Photoelectrochemical studies show that the heterojunction has succeeded in promoting the separation of photogenerated charges. The study lays the groundwork for optimizing synthesis methods and designing nanocomposites with superior photocatalytic activities. [ABSTRACT FROM AUTHOR]

Synthesis of Ag-coated BiVO4 nano/heterostructured photocatalysts was carried out through a two-step process, and their performance was comprehensively evaluated, in this study. The as-synthesized photocatalysts were characterized by X-ray diffraction (XRD), Fourier transfer infrared spectroscopy (FT-IR), Raman spectroscopy, transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), and UV–Vis diffuse reflectance spectroscopy (UV–Vis DRS). Ag nanoparticles were successfully coated on walnut-like BiVO4 microarchitectures assembled from sphere-shaped nanostructures. Based on the optical results, Ag coating could effectively promote visible light absorption and greatly increase the light absorption threshold because of the synergistic effect on the surface plasmon resonance (SPR). Evaluations of nano/heterostructures' photo-reactivity were conducted by photodegradation of methylene blue (MB) in an aqueous environment subject to visible light irradiation (VLI). All Ag-BiVO4 nano/heterostructured samples showed improved photocatalytic efficiencies compared to Pure-BiVO4 sample, as approved by optical absorption studies. The Schottky scheme mechanism, which introduced a charge transfer route at the metal–semiconductor interface, was also discussed for photocatalytic reactions. [ABSTRACT FROM AUTHOR]

Given its favorable physical and chemical properties, Bismuth vanadate (BiVO4) is a commonly studied metal oxide semiconductor for photocatalytic applications. However, BiVO4 shows a high recombination rate of photogenerated charges and limited charge transport capacity, which can be addressed by doping it with tungsten. To develop a highly efficient tungsten‐doped BiVO4‐based (W‐BiVO4) photocatalyst, it is necessary to control the dopant content, crystal structure, and morphology. These properties are, in turn, governed by the synthesis conditions. This work describes a pioneering method of microwave‐assisted reflux synthesis of W‐BiVO4, using ethanol as solvent and polyvinyl pyrrolidone (PVP) as a capping agent. Thus, it is possible to perform the synthesis procedure in only 30 min at 78°C, obtaining extremely regular monoclinic W‐BiVO4 nanosquares. Furthermore, the experiments showed that the most efficient photocatalyst contains 3% tungsten as the dopant. Moreover, the direct oxidation of rhodamine B by the photogenerated holes plays a crucial role in the degradation mechanism. Finally, we observed that although the addition of PVP promotes control of the morphology, it results in a poorly efficient material. This low efficiency may be related to the formation of a polymeric coating on the surface of the catalyst or to a high amount of oxygen defects. Finally, we show that the unique interaction of microwaves with the species present in the reaction media influences nanoparticle growth. [ABSTRACT FROM AUTHOR]

The research progress of bismuth vanadate(BiVO4) based heterojunction photocatalytic materials was reviewed・ Aiming at the shortcomings of BiVO4 based heterojunction photocatalytic materials with narrow band gap and high photogenerated carrier recombination rate, heterojunction types of BiVO4 based heterojunction photocatalytic materials were described. The research progress of BiVO4 heterojunction photocatalytic materials in the field of water decomposition, degradation of organic pollutants, reduction of CO2 and heavy metal ions was introduced in detail. The existing problems of BiVO4-based heterojunction photocatalytic materials were analyzed, and the future research focus and direction were prospected. [ABSTRACT FROM AUTHOR]

New toxic-metal-free sustainable yellow pigments have been developed in scheelite-type solid solutions: [(Li0.33Ca0.33La0.33)xBi1-x][MoxV1-x]O4. The developed pigments show a structural transition from monoclinic to tetragonal scheelite-type structures upon the substitution of LiCaLaMoO4 into the BiVO4 system. The absorption edge is gently blue-shifted from the parent BiVO4 by widening the bandgap upon the incorporation of various metal ions such as Li, La, Ca, and Mo into the lattice, allowing different intense yellow hues to be produced. The typical pigment [(LiLaCa)0.198Bi0.8][Mo0.2V0.8]O4 showed the most vivid yellow hue with a b* value of 78.32, which is comparable to the commercial Sicopal yellow (b* = 76.9). Further, the developed toxic-metal-free pigments have high near-infrared reflectance, making them sustainable as eco-friendly cool colorants for paint and plastic formulations. [ABSTRACT FROM AUTHOR]

In the past years, bismuth vanadate (BiVO4) has emerged as rising star and gained much attention for various photocatalytic and electrochemical applications. In this study, our group report the precipitation synthesis of BiVO4 and its photocatalytic properties for the generation of hydrogen (H2). The obtained results demonstrate the H2 generation of 32.4 µmol g−1. Further studies were carried out by employing platinum (Pt) as co-catalyst which dramatically improved the H2 generation. The obtained results show that an enhanced 115.7 µmol g−1 H2 was generated using BiVO4 as photocatalyst in presence of Pt co-catalyst. Further studies also exhibit the presence of good stability of the BiVO4 as photocatalyst and suggested its potential for reusability studies. [ABSTRACT FROM AUTHOR]

High‐efficient photoelectrocatalytic direct ammonia oxidation reaction (AOR) conducted on semiconductor photoanodes remains a substantial challenge. Herein, we develop a strategy of simply introducing ppm levels of Cu ions (0.5–10 mg/L) into NH3 solutions to significantly improve the AOR photocurrent of bare BiVO4 photoanodes from 3.4 to 6.3 mA cm−2 at 1.23 VRHE, being close to the theoretical maximum photocurrent of BiVO4 (7.5 mA cm−2). The surface charge‐separation efficiency has reached 90 % under a low bias of 0.8 VRHE. This AOR exhibits a high Faradaic efficiency (FE) of 93.8 % with the water oxidation reaction (WOR) being greatly suppressed. N2 is the main AOR product with FEs of 71.1 % in aqueous solutions and FEs of 100 % in non‐aqueous solutions. Through mechanistic studies, we find that the formation of Cu−NH3 complexes possesses preferential adsorption on BiVO4 surfaces and efficiently competes with WOR. Meanwhile, the cooperation of BiVO4 surface effect and Cu‐induced coordination effect activates N−H bonds and accelerates the first rate‐limiting proton‐coupled electron transfer for AOR. This simple strategy is further extended to other photoanodes and electrocatalysts. [ABSTRACT FROM AUTHOR]

In this work, a surface dispersed heterojunction of BiVO4-nanoparticle@WO3-nanoflake was successfully prepared by hydrothermal combined with solvothermal method. We optimized the morphology of the WO3 nanoflakes and BiVO4 nanoparticles by controlling the synthesis conditions to get the uniform BiVO4 loaded on the surface of WO3 arrays. The phase composition and morphology evolution with different reaction precursors were investigated in detail. When used as photoanodes, the WO3/BiVO4 composite exhibits superior activity with photocurrent at 3.53 mA cm−2 for photoelectrochemical (PEC) water oxidation, which is twice that of pure WO3 photoanode. The superior surface dispersion structure of the BiVO4-nanoparticle@WO3-nanoflake heterojunction ensures a large effective heterojunction area and relieves the interfacial hole accumulation at the same time, which contributes to the improved photocurrents together with the stability of the WO3/BiVO4 photoanodes. [ABSTRACT FROM AUTHOR]

Regulating the interfacial charge transfer behavior between cocatalysts and semiconductors remains a critical challenge for attaining efficient photoelectrochemical water oxidation reactions. Herein, using bismuth vanadate (BiVO4) photoanode as a model, it introduces an Au binding bridge as holes transfer channels onto the surfaces of BiVO4, and the cyano‐functionalized cobalt cubane (Co4O4) molecules are preferentially immobilized on the Au bridge due to the strong adsorption of cyano groups with Au nanoparticles. This orchestrated arrangement facilitates the seamless transfer of photogenerated holes from BiVO4 to Co4O4 molecules, forming an orderly charge transfer pathway connecting the light‐absorbing layer to reactive sites. An exciting photocurrent density of 5.06 mA cm−2 at 1.23 V versus the reversible hydrogen electrode (3.4 times that of BiVO4) is obtained by the Co4O4@Au(A)/BiVO4 photoanode, where the surface charge recombination is almost completely suppressed accompanied by a surface charge transfer efficiency over 95%. This work represents a promising strategy for accelerating interfacial charge transfer and achieving efficient photoelectrochemical water oxidation reaction. [ABSTRACT FROM AUTHOR]

Bismuth vanadate (BVO) has been established as an efficient photocatalyst for water remediation and energy applications. Its crystal structure stability, high light quantum and electronic transmission efficiency, and outstanding energy utilization capacity are the main reasons for its enhanced utilization as a robust photocatalytic material. Several studies have reported many synthesis methods and strategies to design highly efficient BVO photocatalysts with different shapes, morphologies, facets, oxygen vacancies. This review systematically encapsulates the effects of morphologies on the photodegradation properties. Here, we have surveyed the synthesis methods of BVO photocatalysts followed by their different synthesized morphologies. The photosensitization mechanism whereby the organic dye plays both the role of photosensitizer as well as sample to be degraded is addressed. Further, we have highlighted the general sequential photocatalytic processes and the recent advances on degradation of three model pollutants (Methylene Blue, Rhodamine B and Methyl Orange). The 3 steps photocatalytic mechanism of BVO photocatalysts have discussed. This review provides also the effects of crystal facets, heterojunction BVO materials and elemental doping on the photocatalytic efficiency. Finally, current status, challenges to improve the photoactivity and the future possible scenarios are summarized. [ABSTRACT FROM AUTHOR]

Abstract BiVO4 is one of the most promising photoanode materials for photoelectrochemical (PEC) solar energy conversion, but it still suffers from poor photocurrent density due to insufficient light‐harvesting efficiency (LHE), weak photogenerated charge separation efficiency (ΦSep), and low water oxidation efficiency (ΦOX). Herein, we tackle these challenges of the BiVO4 photoanodes using systematic engineering, including catalysis engineering, bandgap engineering, and morphology engineering. In particular, we deposit a NiCoOx layer onto the BiVO4 photoanode as the oxygen evolution catalyst to enhance the ΦOX of Fe‐g‐C3N4/BiVO4 for PEC water oxidation, and incorporate Fe‐doped graphite‐phase C3N4 (Fe‐g‐C3N4) into the BiVO4 photoanode to optimize the bandgap and surface areas to subsequently expand the light absorption range of the photoanode from 530 to 690 nm, increase the LHE and ΦSep, and further improve the oxygen evolution reaction activity of the NiCoOx catalytic layer. Consequently, the maximum photocurrent density of the as‐prepared NiCoOx/Fe‐g‐C3N4/BiVO4 is remarkably boosted from 4.6 to 7.4 mA cm−2. This work suggests that the proposed systematic engineering strategy is exceptionally promising for improving LHE, ΦSep, and ΦOX of BiVO4‐based photoanodes, which will substantially benefit the design, preparation, and large‐scale application of next‐generation high‐performance photoanodes.

Addressing the global environmental problem of water splitting to produce hydrogen fuel by solar energy is receiving so much attention. In water splitting, the essential problem to solve is the development of efficient catalysts for oxygen production. In this paper, having the prospect for a practical application of photocatalysts to artificial photosynthesis, molecular mechanisms in the current literature are briefly reviewed. At first, recent progress in the function of the Mn cluster at the natural photosystem II is briefly described. The kinds of devices in which oxygen evolution reaction (OER) catalysts are used were designated: water electrolyzers, photoelectrodes, and photocatalysts. Some methods for analyzing molecular mechanisms in OER catalysis, emphasized by the FTIR method, are shown briefly. After describing common OER mechanisms, the molecular mechanisms are discussed for TiO2 and BiVO4 photoelectrodes with our novel data, followed by presenting OER co-catalysts of IrO2, RuO2, NiO2, and other metal oxides. Recent reports describing OER catalysts of perovskites, layered double hydroxides (LDH), metal–organic frameworks (MOF), single-atom catalysts, as well as metal complexes are reviewed. Finally, by comparing with natural photosystem, the required factors to improve the activity of the catalysts for artificial photosynthesis will be discussed.

Abstract Regulating the interfacial charge transfer behavior between cocatalysts and semiconductors remains a critical challenge for attaining efficient photoelectrochemical water oxidation reactions. Herein, using bismuth vanadate (BiVO4) photoanode as a model, it introduces an Au binding bridge as holes transfer channels onto the surfaces of BiVO4, and the cyano‐functionalized cobalt cubane (Co4O4) molecules are preferentially immobilized on the Au bridge due to the strong adsorption of cyano groups with Au nanoparticles. This orchestrated arrangement facilitates the seamless transfer of photogenerated holes from BiVO4 to Co4O4 molecules, forming an orderly charge transfer pathway connecting the light‐absorbing layer to reactive sites. An exciting photocurrent density of 5.06 mA cm−2 at 1.23 V versus the reversible hydrogen electrode (3.4 times that of BiVO4) is obtained by the Co4O4@Au(A)/BiVO4 photoanode, where the surface charge recombination is almost completely suppressed accompanied by a surface charge transfer efficiency over 95%. This work represents a promising strategy for accelerating interfacial charge transfer and achieving efficient photoelectrochemical water oxidation reaction.

We report a photochemical bismuth vanadate (BiVO4) sensing material, which possesses a large proportion of (110) and (011) facets combined with the additional (111) facets, for the selective detection of ultra‐low concentration hydrogen sulfide (H2S) driven by visible light. Specifically, the obtained octadecahedron BiVO4 (Octa‐BiVO4) performs a high response value (67) and short response time (47.4 s) to 100 ppm H2S with good stability for nearly 100 days, as well as undisturbedness by moist air. With the combination of experimental and theoretical calculation results, the adsorption and carrier transfer behaviors of H2S molecules on the Octa‐BiVO4 crystal surface are investigated. By adjusting the ratio of different crystal facets and controlling the facets with characteristic adsorption, we achieve improved anisotropic photoinduced carrier separation and high selectivity for a specific gas. Furthermore, this facial facet engineering can be extended to the synthesis of other sensing materials, offering huge opportunities for fundamental research and technological applications. [ABSTRACT FROM AUTHOR]

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Although spatial charge separation between different facets of semiconductor crystals has been recognized as a general strategy in photocatalysis, the vital role of crystal morphology symmetry in charge separation properties still remains elusive. Herein, taking monoclinic bismuth vanadate (BiVO4) as a platform, we found distinct charge separation difference via rationally tailoring the morphology symmetry from octahedral to truncated octahedral crystals. For octahedral BiVO4, photogenerated electrons and holes can be separated between edges and quasi-equivalent facets. However, as for truncated octahedral crystals, photogenerated electrons tend to transfer to {010} facets while photogenerated holes prefer to accumulate on {120} facets, thus realizing the spatial separation of photogenerated charge between different facets. Morphology tailoring of BiVO4 crystals leads to a significantly improved photogenerated charge separation efficiency and photocatalytic water oxidation activity. The built-in electric field for driving the separation of photogenerated electrons and holes is considered to be modulated by tuning the morphology symmetry of BiVO4 crystals. This work discloses the significant roles of morphology symmetry in photogenerated charge separation and facilitates the rational design of artificial photocatalysts. [ABSTRACT FROM AUTHOR]

The bismuth vanadate samples (In-BiVO4) have been synthesized through sol-gel method. The typical XRD patterns of samples have revealed that the doped In ions could enter the lattice of BiVO4. The results indicate that doped In ions improve the photocatalytic properties of the BiVO4 for the degradation of methyl orange. The as-prepared In doped BiVO4 photocatalysts exhibit strong visible light absorption capacity than that of bare crystalline BiVO4. Density functional theory calculations show that doped indium ions can effectively promote the separation of photogenerated holes. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) are a notable group of indoor air pollutants released by household products. These substances are commonly employed as solvents in industrial operations, and some of them are recognized or suspected to be cancer-causing or mutagenic agents. Due to their high volatility, VOCs are typically present in surface waters at concentrations below a few micrograms per liter. However, in groundwater, their concentrations can reach levels up to thousands of times higher. This study analyses the applicability of the photoelectrochemical (PEC) sensing of VOCs in aqueous medium. Tungsten oxide and bismuth vanadate photoanodes were tested for PEC sensing of xylene, toluene, and methanol in sodium chloride and sodium sulfate electrolytes. The crystalline structure and morphology of coatings were analyzed using XRD and SEM analyses. Photoelectrochemical properties were evaluated using cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. The results of the study show that aromatic compounds tend to block the surface of the photoelectrode and interfere with the PEC sensing of other substances. WO3 photoanode is found to be suitable for the PEC sensing of methanol under the mild conditions in aqueous electrolytes; however, electrode engineering and assay optimization are required to achieve better detection limits. [ABSTRACT FROM AUTHOR]

The bismuth vanadate samples (In-BiVO4) have been synthesized through sol-gel method. The typical XRD patterns of samples have revealed that the doped In ions could enter the lattice of BiVO4. The results indicate that doped In ions improve the photocatalytic properties of the BiVO4 for the degradation of methyl orange. The as-prepared In doped BiVO4 photocatalysts exhibit strong visible light absorption capacity than that of bare crystalline BiVO4. Density functional theory calculations show that doped indium ions can effectively promote the separation of photogenerated holes. [ABSTRACT FROM AUTHOR]

Due to the slow kinetics of water oxidation, severe surface charge recombination is a significant energy loss that impedes efficient photoelectrochemical performance. Constructing a scheelite bismuth vanadate (BiVO 4) electrode with an oxygen evolution catalyst and doping is an effective way to increase the performance of water oxidation. Importantly, this attempt avoids any sacrificial agents and binders. Using a single-step hydrothermal-based method, a nickel-iron (oxy)hydroxide is deposited unlike conventional two-step photoelectrodeposition method onto the surface of BiVO 4 doped with 2% molybdenum dopant. Through this method, the as-formed nickel-iron (oxy)hydroxide is in γ-NiOOH and β-FeOOH forms. The difficulty of transporting charge carriers-hole pairs along the BiVO 4 is reduced by incorporating molybdenum. A low-cost but efficient co-catalyst, nickel-iron (oxy)hydroxide is introduced to surpass the charge recombination on BiVO 4. A comparison of photocurrent density-voltage and photocurrent density-time curves with and without an oxygen evolution catalyst reveals that nickel-iron (oxy)hydroxide accelerates the anodic photocurrent of the BiVO 4 from ∼1 to 5 mA cm−2 (1.23 V vs. RHE). Simultaneously, the molybdenum-doped BiVO 4 layer with a small band gap and extremely good photoelectrostability and the (oxy)hydroxide layer with good conductivity provide synergetic enhancement of both stability over 12 hours and photocurrent density. • Nickel-iron oxy hydroxide were coated on Mo:BiVO 4 via one step hydrothermal method. • Results suggest that nickel-iron oxy hydroxide is in γ-NiOOH and β-FeOOH forms. • The composite shows photocurrent of 5 mA cm−2 and onset potential of approximately 0.5 V. • The composite has stability over 12 hours. [ABSTRACT FROM AUTHOR]

Under UV and visible light irradiation, semiconductive photocatalysis is showing a tendency for disinfection and mineralization of organic molecules and other dangerous contaminants. Some heavy metals and refractive organic molecules are not transferred to other phases, making mineralization difficult. The hydrothermal technique is used to make bismuth vanadate and a composite of bismuth vanadate with silver and black phosphorene in this research. The concentration of black phosphorene is varied from 1 to 3%. X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) spectroscopy, and ultraviolet (UV) spectroscopy is used to investigate the morphological, structural, and optical features of the manufactured sample. The photocatalytic degradation of contaminants is accomplished by the process of photocatalysis. Methylene blue (MB) is a target pollutant for photocatalytic degradation in this work. The BiVO4/Ag/black phosphorene 3% composite degrades 99% of MB in 70 min. [ABSTRACT FROM AUTHOR]