Photoelectrochemical Water Splitting Systems Research Articles

Piezoelectric Materials and Pyroelectric Materials:High Efficient Catalysts for Photoelectrochemical Water Splitting.

Directly transforming solar energy into chemical compounds via photocatalytic water splitting can continually producing hydrogen, regarded as one of the ultimate sustainable energy sources. The key point of achieving high photoelectrochemical (PEC) water splitting performance depends on the successful design and synthesis of high-efficient photocatalysts. However, the slow separation and fast recombination of photo generated charge carriers greatly limit the utilization of solar energy, resulting in low PEC water splitting efficiency. Recently, piezoelectric/pyroelectric effect assisted PEC water splitting brings new sight on improving charger separate and transfer behaviors. In this review, the recent advancements and state-of-the-art progress in piezoelectric/pyroelectric effect assisted PEC water splitting are summarized and discussed. Different types of photocatalysts are classified according to their chemical constitutions and the corresponding advantages of each type are also discussed. Furthermore, the progress of coupling piezoelectric effect and pyroelectric effect in one PEC water splitting system is also introduced. Finally, the prospects, critical challenges and promising strategies for the application of piezoelectric/pyroelectric materials in PEC water splitting are highlighted.

Surface Engineering of BiVO4 Photoanodes for Photoelectrochemical Water Splitting: Recent Advances

AbstractEnergy 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.

Ultrathin layer TAFC on BiVO4 with ligand-to-metal charge transfer enhances built-in electric field for boosting photoelectrochemical water oxidation

To reveal the mechanism of charge transfer between interfaces of BiVO4-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 BiVO4 to form photoanodes. The results show that the BiVO4/TAFC achieves a superior photocurrent density (4.97 mA cm−2 at 1.23 VRHE). 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 BiVO4/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.

Self-assembled monolayer mediated fast charge transport of Sb2(S,Se)3 photocathode enabling high-performance unbiased water splitting

The photoelectrochemical (PEC) water splitting system, capable of generating green hydrogen fuel, is crucial for achieving carbon net zero. However, the performance of the photocathode, responsible for the hydrogen evolution reaction, remains suboptimal. We propose bottom interface engineering using a self-assembled monolayer (SAM) to enhance the quality of the Sb2(S,Se)3 absorber layer. The SAM, composed of (3-aminopropyl)triethoxysilane (APTES), is introduced on the Au substrate to enhance adhesion between the substrate and the Sb2(S,Se)3 absorber. Notably, the APTES treatment facilitates the formation of strong electrophile functional groups on the substrate, which predominantly attract tartrate-Sb-Se ionic clusters in the precursor ink. This interaction between the precursor and the substrate induces preferential nucleation of Sb2Se3 near the substrate, followed by Sb2S3 formation at a later stage near the top surface. The APTES-treated Sb2(S,Se)3 photocathodes exhibit a steep band energy gradient, resulting in a photocurrent density of 16 mA cm–2, an onset potential of 0.24 V versus the standard hydrogen electrode, and stability of 24 h in neutral electrolyte (0.5 M K-Pi, pH 6.13). By combining the APTES-treated Sb2(S,Se)3 photocathode with a perovskite photoanode, the co-planar PEC–PEC water splitting device achieves a remarkable solar-to-hydrogen efficiency of 6.5 % under unbiased conditions, along with operating stability for over 120 min. This study suggests that SAM treatment-based interface engineering could be a potential breakthrough in improving the performance of chalcogenide photocathodes in solar-driven water splitting systems.

All-perovskite-based unassisted photoelectrochemical water splitting system for efficient, stable and scalable solar hydrogen production

All-perovskite-based unassisted photoelectrochemical water splitting system for efficient, stable and scalable solar hydrogen production

Molecular dynamics simulation of thermal transport properties of phonons at interface of Au-TiO<sub>2</sub> photoelectrode

Thermoplasmonics originating from the relaxation process of plasmon resonances in nanostructures can be utilized as an efficient and highly localized heat source in solar-hydrogen conversion, but there have been few researches on the interfacial heat transport properties of photoelectrode with the thermoplasmonics effect in a photoelectrochemical water splitting system. In this work, the effects of temperature, interfacial coupling strength and the addition of graphene layers on the interfacial thermal conductance of Au-TiO<sub>2</sub> electrodes are investigated by the non-equilibrium molecular dynamics simulation, and the variation of interfacial thermal conductance is analyzed by the phonon density of states. The results show that the interfacial thermal conductivity is increased by 78.55% when the temperature increases from 300 to 800 K. This is related to the fact that more low-frequency phonons participate in the interface heat transport, allowing more heat to be transferred to TiO<sub>2</sub> to promote the interface reaction. As the coupling strength of the Au-TiO<sub>2</sub> interface increases, the interfacial thermal conductivity of the electrode increases and then tends to stabilize. The interfacial thermal conductivity can be optimized by increasing the degree of overlap of the phonon state densities of Au and TiO<sub>2</sub>. The addition of a single layer of graphene can increase the interfacial thermal conductivity to 98.072 MW⋅m<sup>–2</sup>⋅K<sup>–1</sup>, but the addition of 2 and 3 layers of graphene can hinder interfacial heat transfer in Au and TiO<sub>2</sub> due to the interaction between the layers of graphene. When adding graphene layer, medium-frequency phonons and high-frequency phonons are stimulated to participate in the interfacial heat transfer, but with the increase of the graphene layers, the number of low-frequency phonons in a range of 0—30 THz decreases, and these low-frequency phonons make the greatest contribution to the interfacial thermal conductivity. The obtained results are useful in regulating the thermal transport properties of the photoelectrode interface, which can provide new insights into and theoretical basis for the design and construction of composite photoelectrodes.

Unveiling the Influence of Sulfur Doping on Photoelectrochemical Performance in BiVO4/FeOOH Heterostructures.

BiVO4 is a promising photoanode for photoelectrochemical (PEC) water splitting but suffers from high charge carrier recombination and sluggish surface water oxidation kinetics that limit its efficiency. In this work, a model of sulfur-incorporated FeOOH cocatalyst-loaded BiVO4 was constructed. The composite photoanode (BiVO4/S-FeOOH) demonstrates an enhanced photocurrent density of 3.58 mA cm-2, which is 3.7 times higher than that of the pristine BiVO4 photoanode. However, the current explanations for the generation of enhanced photocurrent signals through the incorporation of elements and cocatalyst loading remain unclear and require further in-depth research. In this work, the hole transfer kinetics were investigated by using a scanning photoelectrochemical microscope (SPECM). The results suggest that the incorporation of sulfur can effectively improve the charge transfer capacity of FeOOH. Moreover, the oxygen evolution reaction model provides evidence that S-doping can induce a "fast" surface catalytic reaction at the cocatalyst/solution interface. The work not only presents a promising approach for designing a highly efficient photoanode but also offers valuable insights into the role of element doping in the PEC water-splitting system.

(Invited) Chirality-Induced Spin Selectivity Enabling Efficient Spin-Dependent Oxygen Evolution Reaction and High-Performance Photoelectrochemical Water Splitting

The sluggish and complex multi-step oxygen evolution reaction (OER) remains an obstacle to bias-free photoelectrochemical water-splitting systems. Several theoretical and experimental studies have suggested that OER efficiency can be significantly enhanced in chiral material-based photoanodes by utilizing the chirality-induced spin selectivity (CISS) phenomenon. The final product at the photoanode is the oxygen molecules, where the spin alignment of intermediate radicals is favorable to the generation of triplet 3O2 (most stable molecular oxygen species). Considering the energy difference between a singlet 1O2 and triplet 3O2, spin-dependent chemical reactions combined with the CISS phenomenon can play a crucial role in the OER process. Moreover, chiral material-based photoanodes are capable of paralleling spin distribution on the catalytic surface. The resulting spin-aligned intermediate radicals can promote the generation of spin-allowed triplet 3O2 over that of singlet oxygen, while hindering the formation of hydrogen peroxide, in turn leading to the enhanced STH efficiency of the overall PEC water-splitting system. In this regard, chiral materials (as a spin-filter layer) have been recognized as promising candidates for achieving a breakthrough in the solar-to-hydrogen efficiency of water-splitting devices. Herein, we report that the CISS phenomena can become an impressive approach by adopting chiral 2D organic-inorganic hybrid perovskites (OIHPs) as a spin-filtering layer on the 3D OIHP photoanode. Our chiral 2D OIHP-based water-splitting device achieved enhanced oxygen evolution performance with a reduced overpotential of 0.2 V, high fill factor, and increased photocurrent of 22 mA cm–2 at 1.2 VRHE compared to a device without a spin-filtering layer. For unbiased water splitting, a perovskite-based photocathode decorated with a spatially decoupled hydrogen evolution reaction catalyst is fabricated. This decoupled geometry enables the physical protection of the perovskite layer from the electrolyte, thus allowing excellent stability for over 100 h. To investigate the overall water splitting performance, this perovskite photocathode is connected in parallel with spin-filtering layer adopted photoanode based on chirality-induced spin selectivity. An unbiased solar water splitting was achieved using all the OIHP photoelectrodes, resulting in a remarkable unassisted solar-to-hydrogen efficiency of ~12% and a continuous 10 h stable operation.

Key Strategies on Cu2O Photocathodes toward Practical Photoelectrochemical Water Splitting.

Cuprous oxide (Cu2O) has been intensively in the limelight as a promising photocathode material for photoelectrochemical (PEC) water splitting. The state-of-the-art Cu2O photocathode consists of a back contact layer for transporting the holes, an overlayer for accelerating charge separation, a protection layer for prohibiting the photocorrosion, and a hydrogen evolution reaction (HER) catalyst for reducing the overpotential of HER, as well as a Cu2O layer for absorbing sunlight. In this review, the fundamentals and recent research progress on these components of efficient and durable Cu2O photocathodes are analyzed in detail. Furthermore, key strategies on the development of Cu2O photocathodes for the practical PEC water-splitting system are suggested. It provides the specific guidelines on the future research direction for the practical application of a PEC water-splitting system based on Cu2O photocathodes.

Photo-Electro-Biochemical H2 Production Using the Carbon Material-Based Cathode Combined with Genetically Engineered Escherichia coli Whole-Cell Biocatalysis.

Abio/bio hybrids, which incorporate biocatalysts that promote efficient and selective material conversions under mild conditions into existing catalytic reactions, have attracted considerable attention for developing new catalytic systems. This study constructed a H2 -forming biocathode based on a carbon material combined with whole-cell biocatalysis of genetically-engineered-hydrogenase-overproducing Escherichia coli for the photoelectrochemical water splitting for clean H2 production. Low-cost and abundant carbon materials are generally not suitable for H2 -forming cathode due to their high overpotential for proton reduction; however, the combination of the reduction of an organic electron mediator on the carbon electrode and the H2 formation with the reduced mediator by the redox enzyme hydrogenase provides a H2 -forming cathodic reaction comparable to that of the noble metal electrode. The present study demonstrates that the recombinant E. coli whole cell can be employed as a part of the H2 -forming biocathode system, and the biocathode system wired with TiO2 photoanode can be a photoelectrochemical water-splitting system without external voltage assistance under natural pH. The findings of this study expand the feasibility of applications of whole-cell biocatalysis and contribute to obtaining solar-to-chemical conversions by abio/bio hybrid systems, especially for low-cost, noble-metal-free, and clean H2 production.

Constructing heterogeneous structure to improve the redox ability of Nb2O5 photoanode and effectively actuate carrier separation for efficient photoelectrochemical water splitting system

Niobium-based oxide semiconductors face the problems of narrow photo-response range and fast carrier recombination in the field of photoelectrochemical (PEC) water splitting. Based on the above problems, we chose the idea of constructing a heterojunction and successfully loaded Ag2O onto Nb2O5 photoanode by ion precipitation to effectively enhance the carrier separation efficiency and broaden its photo-response range. The results show that the composite electrode NA-3 exhibits excellent photoelectrocatalysis performance under illumination and bias voltage. The photocurrent density was increased to 0.481 mA/cm2, approximately 2.88 times that of the Nb2O5 photoanode, and a negative onset potential shift of 139 mV was achieved. The higher ABPE and IPCE values of composite electrode indicate its higher catalytic conversion ability and quantum efficiency. The Mott-Schottky results reveal that the loading of Ag2O not only causes a negative shift of Vfb, improves Faraday transfer efficiency, but also reduces WDep at the electrode/electrolyte interface, effectively improving the photocatalytic performance of the photoanode. This work promotes the development of Nb2O5 materials in the field of PEC water splitting through the idea of constructing heterojunctions, and provides an effective strategy for suppressing carrier recombination to achieve highly active photoanodes.

Correlation between the Experimental and Theoretical Photoelectrochemical Response of a WO3 Electrode for Efficient Water Splitting through the Implementation of an Artificial Neural Network

Since the discovery of photoelectrochemical (PEC) water splitting with titanium dioxide electrodes in the presence of ultraviolet light, much work has been conducted to build an effective PEC water splitting system and develop novel photoelectrodes. Using a facile and controllable electrodeposition method, a thin tungsten trioxide (WO3) film electrode onto a stainless steel (SS) substrate was synthetized. The effect of the deposition time on the structural, morphological, optical, and electrical properties of the as-grown WO3 thin films was assessed. XRD spectra of the obtained films reveal the polycrystalline nature of WO3 with a triclinic phase and exhibit a sharp transition to the (002) plane when the deposition time was extended beyond 10 min. The surface morphology showed a remarkable change in the grain size, thickness, and surface roughness when varying the deposition time. UV–Vis spectrophotometry revealed that the optical band gap values of WO3 decreased from 1.78 to 1.36 eV by extending the electrodeposition duration from 10 to 30 min, respectively. Notably, as indicated from the PEC measurements, the obtained photoelectrode exhibited the effects of the deposition time on the photocurrent density, and the maximum value obtained was around 0.07 mA cm−2 for the sample deposited at 10 min. Finally, this study presents for the first time an artificial neural network model to predict the PEC behavior of the prepared photoanode, with a highly satisfactory performance of less than 0.05% error. The low cost and simply synthetized WO3/SS electrode with superior electrochemical performance and the excellent correlation between the experimental and theoretical results demonstrate its potential for practical application in water splitting and hydrogen production.

Enhanced photoelectrochemical water splitting efficiency of CdS through Fe-S-Cd carrier channel facilitated interfacial charge transfer

Semiconductor materials with high charge separation efficiency and mobility will perform well in photoelectrochemical water splitting efficiency. In this study, active cadmium sulfide (CdS-T) with exposed (0 0 2) crystal planes was prepared through a simple hydrothermal method and electrodeposition, and composite CdS-T/FeOOH was formed by coupling with hydroxylated iron oxide (FeOOH). Here, the (2 0 0) active crystal plane of CdS constructed a Fe-S-Cd charge carrier channel with FeOOH, which accelerated the migration of photogenerated carriers. In this system, the presence of the Fe-S-Cd charge carrier channel promoted the transfer of carriers between CdS and FeOOH. Meanwhile, FeOOH acts as an auxiliary catalyst, which can effectively promote the water splitting reaction on the material surface. With the effect of the Fe-S-Cd charge carrier channel, the photoelectrochemical (PEC) performance of the CdS and FeOOH photoanode was greatly improved. According to PEC testing, at 1.23 V vs RHE, the photocurrent density reached 9.92 mA/cm2 (2.88 times that of the pure CdS photocurrent density). Lastly, the carrier migration mechanism of the system is explained in conjunction with density functional theory (DFT) calculations. This study provides a new perspective for designing and manufacturing environmentally friendly, sunlight-driven photoanodes for use in photoelectrochemical water splitting systems.

Chirality-Induced Spin Selectivity of Chiral 2D Perovskite Enabling Efficient Spin-Dependent Oxygen Evolution Reaction.

The sluggish and complex multi-step oxygen evolution reaction remains an obstacle to bias-free photoelectrochemical water-splitting systems. Several theoretical studies have suggested that spin-aligned intermediate radicals can significantly enhance the kinetic rates for oxygen generation. Herein, it is reported that the chirality-induced spin selectivity phenomena can become an impressive approach by adopting chiral 2D organic-inorganic hybrid perovskites as a spin-filtering layer on the photoanode. This chiral 2D perovskite-based water-splitting device achieves enhanced oxygen evolution performance with a reduced overpotential of 0.14V, high fill factor, and 230% increased photocurrent compared to a device without a spin-filtering layer. Moreover, combined with a superhydrophobic patterning strategy, this device realizes excellent operational stability by sustaining ≈90% of the initial photocurrent, even after 10h.

A review on the design of nanostructure-based materials for photoelectrochemical hydrogen generation from wastewater: Bibliometric analysis, mechanisms, prospective, and challenges

Years of study have shown that creating a commercial photoelectrode to solve particular bottlenecks, such as low charge separation and injection efficiency, short carrier diffusion length and lifespan, and poor stability, requires the employment of a variety of components. Developing photovoltaic-electrolysis, photocatalytic, and photoelectrochemical approaches to accelerate hydrogen production from solar energy has been highly competitive. Photoelectrochemical water splitting utilizing nanoporous materials is one of the promising approaches to produce hydrogen more efficiently, cost-effectively, and on a long-term basis. Nanoporous materials have been highly used in photoelectrochemical water-splitting systems and are crucial in numerous applications. Those materials have a porous structure and excellent conductivity, enabling the deposition of transition metal atoms and electrochemically active chemicals on a large active surface area. However, there remains a dearth of review articles exploring the application of nanoporous materials in photoelectrochemical reactions. Therefore, this review provides bibliometric statistics and various perspectives on a range of nanoporous materials, including indium, nickel, gold, copper, lead, silver, aluminum, silicon, tin, iron, zinc, titanium, bismuth vanadate, cadmium sulfide, and zeolites. Additionally, this review offers a comprehensive assessment of worldwide studies on utilizing nanoporous materials in photoelectrochemical cells. We show how morphological modifications to materials may improve charge transfer and, as a consequence, overall power conversion efficiency.ke The superior catalytic performance of nanostructures with varying levels of complexity has been discovered in photoelectrochemical reactions. Finally, significant issues and future research directions in the domains are discussed.

Progress and Perspectives for Solar‐Driven Water Electrolysis to Produce Green Hydrogen

AbstractSolar‐driven water electrolysis has been considered to be a promising route to produce green hydrogen, because the conventional water electrolysis system is not completely renewable as it requires power from nonrenewable fossil fuel sources. This review emphasizes the strategies for solar‐driven water electrolysis, including the construction of photovoltaic (PV)‐water electrolyzer systems, PV‐rechargeable energy storage device‐water electrolyzer systems with solar energy as the sole input energy, and photoelectrochemical water splitting systems. The basic discussions of the above strategies for solar‐driven water electrolysis are first presented. Meanwhile, replacing the oxygen evolution reaction with the electrooxidation of organic compounds can effectively improve the efficiency of water splitting. Also, solar‐driven seawater electrolysis greatly broadens the practical applications due to the abundant reserves of seawater. Recent years have witnessed great development in the field of solar‐driven water electrolysis. The recent research development in the area is subsequently reviewed. Finally, perspectives on the existing challenges along with some opportunities for the further development of solar‐driven water electrolysis are provided.

Magnetic-thermal external field activate the pyro-magnetic effect of pyroelectric crystal (NaNbO3) to build a promising multi-field coupling-assisted photoelectrochemical water splitting system

Rationalizing the external field advantage and manipulating more carrier separation is of great significance for expanding the research of external field-assisted photoelectrochemical (PEC) water splitting. Hence, we choose NaNbO3 material with pyroelectric properties for the realization of an efficient multi-field coupled-assisted PEC water splitting system using magnetic and temperature fields for the first time. Detailed experimental results show that the enhancement of photoelectric performance by magnetic fields seems to be limited. However, it is amazing that the coupling effect of magnetic and thermal field triggers the generation of pyro-magnetic effect, which breaks the limitation of non-radiative recombination of magnetic field manipulated carriers, and significantly improves the performance of PEC water splitting. The multi-field coupling drive the current density of the photoanode to span to 0.45 mA at 1.23 V vs. RHE (3 times higher than photocurrent). The first principle density functional theory (DFT) calculation is combined with experimental tests to fundamentally understand the interrelationship between crystal structure changes, charge density distribution and external fields, and the effect on catalytic performance. This research provides insights into the interaction mechanism between external fields and the radiative/non-radiative recombination of manipulating carriers. Insights are provided for the establishment of a multi-field coupling-assisted PEC water splitting system.

Promotion of photo-induced charge carrier separation in a heterostructure via introducing an enhanced polarization electric field

Titanium dioxide (TiO2) has been well adopted as the photocatalyst which possesses the highest possibility for application. Its integration in photoelectrochemical (PEC) system would further benefit the practical application. The effective separation and utilization of photo-induced charge carriers are still the key to enhance the performance in a PEC water splitting system. A Au/BiFeO3/TiO2 ternary heterostructure with an enhanced polarization electric field was prepared by doping Ca and Cr ions in pure BiFeO3, which resulted in a 4.6-fold higher photocurrent density than that of the pure TiO2 photoanode for the oxygen evolution reaction (OER) at 1.23 V vs. RHE. We attributed this improvement to a synergistic effect of the ferroelectric polarization electric field and ternary heterostructure, which effectively promotes the separation and utilization of photo-induced charge carriers. In the Au/BiFeO3/TiO2 heterostructure, ferroelectric BiFeO3, especially Ca and Cr doped BiFeO3, can create an electric field with spontaneous polarization, and the as-formed built-in field at the interface provides a favorable channel for the separation of photo-induced electrons and holes. After poling with a relatively high electric field, the OER performance of the Au/Bi0.9Ca0.1Fe0.9Cr0.1O3/TiO2 photoanode can be further improved, which confirms the positive effect of the ferroelectric polarization electric field on promoting charge separation. This work extends the application of ferroelectric materials in the PEC research field and highlights the significant role of polarization electric fields in promoting PEC performance.

A novel BiVO4/DLC heterojunction for efficient photoelectrochemical water splitting

Photoelectrochemical (PEC) water splitting is a promising technology to produce renewable hydrogen, which still faces problems of low photoelectric efficiency and instability. This work introduces a novel Type II heterojunction consisting of BiVO4 thin film and diamond-like carbon (DLC) to the PEC system as a photoanode and achieves an increased PEC water-splitting activity. Compared to the pure BiVO4, the BiVO4/DLC heterojunction has an increased photocurrent density from 0.79 mA cm−2 to 2.39 mA cm−2 at 1.23 V vs RHE, and the IPCE from 4.8 % to 23.4 %. After 120 min (180 cycles) of PEC water splitting, the BiVO4/DLC heterojunction retains up to 82.3 % of the initial photocurrent density value, while the pure BiVO4 has only 33.99 % remaining under the same conditions. Furthermore, the PEC system of BiVO4/DLC reaches the evolution rate of hydrogen of over 0.32 mmol h−1 cm−2, which is much higher than that of its counterparts. We ascribe the enhancement in PEC performance to the Type II heterojunction photoanodes that greatly promote carrier mobility and reduce the recombination rate of electron-hole pairs. We also identify that the band bending and depletion layer are the main reasons for the decrease in charge transfer and interface resistance. It is demonstrated that the sp2 carbon phase in DLC acts as a conductive channel to improve the separation and migration efficiency of free carriers, while the sp3 carbon phase provides stable support and passivation effect to the photoanode, thereby leading to an enhancement for both PEC water splitting performance and the long-time stability. This work provides an effective way to improve the BiVO4 photoanode-based PEC water-splitting systems.

Magnetic field enhancement of the FeCoSe2 photoanode for the oxygen evolution reaction by adjusting the hole density to reduce competitive adsorption between Fe and Co in a photoelectrochemical water-splitting system

FeCoSe2 has fast oxygen evolution due to polarization electric field and d-band center. However, the large adsorption energy of Fe slows the reaction. Magnetic field reduces Fe's adsorption, enhancing OER performance.