Hematite Photoelectrodes Research Articles

Correlating activities and defects in (photo)electrocatalysts using in-situ multi-modal microscopic imaging

Photo(electro)catalysts use sunlight to drive chemical reactions such as water splitting. A major factor limiting photocatalyst development is physicochemical heterogeneity which leads to spatially dependent reactivity. To link structure and function in such systems, simultaneous probing of the electrochemical environment at microscopic length scales and a broad range of timescales (ns to s) is required. Here, we address this challenge by developing and applying in-situ (optical) microscopies to map and correlate local electrochemical activity, with hole lifetimes, oxygen vacancy concentrations and photoelectrode crystal structure. Using this multi-modal approach, we study prototypical hematite (α-Fe2O3) photoelectrodes. We demonstrate that regions of α-Fe2O3, adjacent to microstructural cracks have a better photoelectrochemical response and reduced back electron recombination due to an optimal oxygen vacancy concentration, with the film thickness and extended light exposure also influencing local activity. Our work highlights the importance of microscopic mapping to understand activity, in even seemingly homogeneous photoelectrodes.

Collaborative role of co-doping and surface modifying for adjusting surface state of hematite to release the photoelectrochemical activity

Inhibition of bulk and interfacial charge carrier recombination is an urgent solution to release furthest the photoelectrochemical potential abilities of hematite photoelectrode. Herein, the Zr-Y dual metal co-doping engineering and Co/Fe dual metal-organic frameworks cocatalyst layer were employed for modifying hematite photoanode. The novel CoFe-MOF/Zr-Y:Fe2O3 nanoarray composite photoanode exhibits higher PEC activity, the photocurrent density at 1.23 V vs.RHE is increased by 4.7 times than that of the pristine α-Fe2O3. The gain in bulk charge separation efficiency was mainly attributed to the synergistic effect between the two doping ions to improve the electrical conductivity. Wherein, Zr4+ doping endows more free electrons in the bulk α-Fe2O3 and Y3+ introduction causes polaron mobility enhancement. For another, co-doping could reduce the recombination surface state, but form the intermediate surface state to promote hole transfer, thus effectively inhibiting the severe recombination of photogenerated electrons and holes. Furthermore, the CoFe-MOF cocatalyst coating with abundant active sites not only expedites the oxygen evolution reaction kinetics process, but also passivates the surface hole trapping state more thoroughly, resulting in efficient interfacial hole transfer and utilization. This work affords a new collaborative role of co-doping and surface modifying effective avenue for adjusting surface state of hematite to release the photoelectrochemical activity.

Unraveling the impact of tetravalent and pentavalent ions on the charge dynamics of hematite photoelectrodes for solar water splitting

This study focuses on understanding the impact of tetravalent (Hf4+) and pentavalent (Nb5+) ions in hematite photoelectrodes using a two-step synthesis approach. Structural, morphological, and compositional analyses confirms that Nb5+ is segregated over the hematite crystal surface while Hf4+ is allocated over the crystal surface and between the fluorine-doped tin oxide substrate (FTO)-hematite interface. Our results indicate that the modifier insertion led to substantial improvements in overall efficiency and photoelectrochemical (PEC) performance. However, it creates additional surface states, as evidenced by shifts in the anodic onset potential (Vonset) observed in the linear sweep voltammetry curves. For Nb-modified photoelectrodes, Vonset shift of ∼20 mV with respect to hematite was observed and confirmed by intensity modulated photocurrent spectroscopy (IMPS). For Hf-modified hematite, this Vonset shift is more pronounced (∼30 mV). When combined with NiFeOx, Nb5+ acted synergistically showing a 4-fold efficiency increase compared to hematite and ∼70 mV cathodic shift in the Vonset. Otherwise, NiFeOx showed no significant impact in the Hf4+ modified hematite photoelectrodes, suggesting that Hf4+ role lies in enhancing electron collection at the FTO-hematite interface. This study not only sheds light on the charge dynamics of modified hematite photoelectrodes but also provides strategies for boosting the PEC devices efficiency.

Insights into the multirole CoAl layered double hydroxide on boosting photoelectrochemical activity of hematite: Application to hydrogen peroxide sensing

As an important compound in many industrial and biological processes, hydrogen peroxide (H2O2) would cause harmfulness to human health at high concentration level. It thus is urgent to develop highly sensitive and selective sensors for practical H2O2 detection in the fields of water monitoring, food quality control, and so on. In this work, CoAl layered double hydroxide ultrathin nanosheets decorated hematite (CoAl-LDH/α-Fe2O3) photoelectrode was successfully fabricated by a facile hydrothermal process. CoAl-LDH/α-Fe2O3 displays the relatively wide linear range from 1 to 2000 μM with a high sensitivity of 132.0 μA mM−1 cm−2 and a low detection limit of 0.04 μM (S/N ≥ 3) for PEC detection of H2O2, which is superior to other similar α-Fe2O3-based sensors in literatures. The (photo)electrochemical characterizations, such as electrochemical impedance spectroscopy, Mott-Schottky plot, cyclic voltammetry, open circuit potential and intensity modulated photocurrent spectroscopy, were used to investigate the roles of CoAl-LDH on the improved PEC response of α-Fe2O3 toward H2O2. It revealed that, CoAl-LDH could not only passivate the surface states and enlarge the band bending of α-Fe2O3, but also could act as trapping centers for holes and followed by as active sites for H2O2 oxidation, thus facilitated the charge separation and transfer. The strategy for boosting PEC response would be help for the further development of semiconductor-based PEC sensors.

Flow cell for operando X-ray photon-in-photon-out studies on photo-electrochemical thin film devices.

Background: Photo-electro-chemical (PEC) water splitting represents a promising technology towards an artificial photosynthetic device but many fundamental electronic processes, which govern long-term stability and energetics, are not yet fully understood. X-ray absorption spectroscopy (XAS), and particularly its high energy resolution fluorescence-detected (HERFD) mode, emerges as a powerful tool to study photo-excited charge carrier behavior under operating conditions. The established thin film device architecture of PEC cells provides a well-defined measurement geometry, but it puts many constraints on conducting operando XAS experiments. It remains a challenge to establish a standardized thin film exchange procedure and concurrently record high-quality photoelectrochemical and X‑ray absorption spectroscopy data that is unperturbed by bubble formation. Here we address and overcome these instrumental limitations for photoelectrochemical operando HERFD-XAS. Methods: We constructed a novel operando photo-electro-chemical cell by computer numerical control milling, guided by the materials' X‑ray and visible light absorption properties to optimize signal detection. To test the cell's functionality, semiconducting thin film photoelectrodes have been fabricated via solution deposition and their photoelectrochemical responses under simulated solar light were studied using a commercial potentiostat in a three-electrode configuration during HERFD-XAS experiments at a synchrotron. Results: We demonstrate the cell's capabilities to measure and control potentiostatically and in open‑circuit, to detect X‑ray signals unperturbed by bubbles and to fluently exchange different thin film samples by collecting high-resolution Fe K-edge spectra of hematite ( α -Fe 2O 3) and ferrite thin film ( MFe 2O 4, M= Zn, Ni) photoelectrodes during water oxidation. Conclusions: Our cell establishes a measurement routine that will provide experimental access of photo-electro-chemical operando HERFD-XAS experiments to a broader scientific community, particularly due to the ease of sample exchange. We believe to enable a broad range of experiments which acquired fundamental insights will spur further photoelectrochemical research and commercialization of water splitting technologies.

Porous and conductive SnO2 ceramics as a promising nanostructured substrate to host photocatalytic hematite coatings: Towards low cost solar-driven water splitting

Commercially viable generation of “green” hydrogen fuel by solar-driven water splitting requires the design of low-cost photoelectrodes and photo-devices with high photoelectrochemical performance. In this regard, conductive and easily fabricated 3D-oxide ceramics with nanosized grains and high porosity are promising as a substrate with a large surface area to host photocatalytic coatings. To test this approach, hematite photoelectrodes have been grown by metal-organic chemical vapor deposition onto free-standing SnO2-based ceramics. The photoanodes formed onto Sb2O5-SnO2, CuO-Sb2O5-SnO2, and on MoO3-Sb2O5-SnO2 substrates in aqueous 1 M NaOH under 1 sun irradiation exhibit photocurrent densities of 0.44 mA/cm2, 0.56 mA/cm2, and 0.39 mA/cm2 at 1.23 V vs. RHE, respectively. The porosity of ceramics results in the 3D growth of a thin hematite coating on ceramic grains in the substrate to a depth of ca. 3 μm. The obtained photoelectrodes are discussed based on the data of photoelectrochemical measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Raman spectroscopy. Routes to improved performance are discussed.

Issue Information

Journal of the American Ceramic SocietyVolume 106, Issue 1 p. 1-5 ISSUE INFORMATIONFree Access Issue Information First published: 01 November 2022 https://doi.org/10.1111/jace.18558AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Graphical Abstract Cover Photograph: Atomic force microscopy topographies and scanning electron microscopy (inserts) images depict the rationally designed interfaces to mitigate the photogenerated charge losses in the hematite photoanode. Image Credit: Images are partially modified from the paper Bedin, K.C., Rodríguez-Gutiérrez , I., Peregrino, L.R.P., Vayssieres, L. and Souza, F. L. Souza. On electron loss lowering at hematite photoelectrode interfaces. Volume106, Issue1January 2023Pages 1-5 RelatedInformation

Flow cell for operando X-ray photon-in-photon-out studies on photo-electrochemical thin film devices

Background: Photo-electro-chemical (PEC) water splitting represents a promising technology towards an artificial photosynthetic device but many fundamental electronic processes, which govern long-term stability and energetics, are not yet fully understood. X-ray absorption spectroscopy (XAS), and particularly its high energy resolution fluorescence-detected (HERFD) mode, emerges as a powerful tool to study photo-excited charge carrier behavior under operating conditions. The established thin film device architecture of PEC cells provides a well-defined measurement geometry, but it puts many constraints on conducting operando XAS experiments. It remains a challenge to establish a standardized thin film exchange procedure and concurrently record high-quality photoelectrochemical and X‑ray absorption spectroscopy data that is unperturbed by bubble formation. Here we address and overcome these instrumental limitations for photoelectrochemical operando HERFD-XAS. Methods: We constructed a novel operando photo-electro-chemical cell by computer numerical control milling, guided by the materials’ X‑ray and visible light absorption properties to optimize signal detection. To test the cell’s functionality, semiconducting thin film photoelectrodes have been fabricated via solution deposition and their photoelectrochemical responses under simulated solar light were studied using a commercial potentiostat in a three-electrode configuration during HERFD-XAS experiments at a synchrotron. Results: We demonstrate the cell’s capabilities to measure and control potentiostatically and in open‑circuit, to detect X‑ray signals unperturbed by bubbles and to fluently exchange different thin film samples by collecting high-resolution Fe K-edge spectra of hematite (α -Fe2O3) and ferrite thin film (MFe2O4, M= Zn, Ni) photoelectrodes during water oxidation. Conclusions: Our cell establishes a measurement routine that will provide experimental access of photo-electro-chemical operando HERFD-XAS experiments to a broader scientific community, particularly due to the ease of sample exchange. We believe to enable a broad range of experiments which acquired fundamental insights will spur further photoelectrochemical research and commercialization of water splitting technologies

Photoelectrochemical Oxygen Evolution on Mesoporous Hematite Films Prepared from Maghemite Nanoparticles

Iron oxides, especially hematite (α-Fe2O3), are promising materials for applications in photoelectrochemical cells and photo-redox catalysis. However, realizing high-performance hematite photoanodes via an environmentally-friendly route remains a great challenge. In this work, we employed a novel approach to prepare mesoscopic hematite photoelectrodes with remarkable performance for water oxidation. Hydrothermally-synthesized maghemite nanoparticles of high crystallinity with a mean particle size of 3.3 nm were deposited onto fluorine doped tin oxide (FTO) transparent conducting glass substrates, followed by heat treatment to convert them into a homogeneous mesoporous hematite layer. A hematite photoanode with a thickness of 220 nm, delivered a maximum photocurrent density of 1.8 mA cm−2 for water oxidation to oxygen at 1.23 VRHE under simulated AM 1.5 irradiation. Upon treating the surface of the hematite photoelectrode with Co(II) cations the photocurrent density nearly doubled at the same potential to 3.32 mA cm−2 placing our new photoelectrode among the best hematite-based photocatalysts for visible light induced water splitting. Further photoelectrochemical analysis provided insights into the factors boosting the performance of the hematite photoanode.

Expediting hole transfer via surface states in hematite-based composite photoanodes.

Regarding the indirect hole transfer route in hematite-based photoelectrodes, the widely accepted viewpoint is that the FeIVO states act as a hole transfer medium, while other types of surface states act as recombination centers. Alternatively, it has rarely been reported that the recombining surface states may contribute to the charge transport in modified photoelectrodes. In this study, we employed CoCr layered double hydroxide (LDH)/Fe2O3 and CoCr LDH/Zr:Fe2O3 as research models to investigate the distinct charge transfer pathways in composite photoanodes. Different from the adverse role of surface states at ∼0.7 V versus the reversible hydrogen electrode (r-SS) in the bare hematite photoelectrodes (Fe2O3 or Zr:Fe2O3), the r-SS in the composite photoanodes (CoCr LDH/Fe2O3 or CoCr LDH/Zr:Fe2O3) served as a hole transfer station to induce high-valent Co cations, and the position of r-SS determined the onset potential of the composite photoelectrodes. Moreover, the FeIVO states still acted as active intermediates to transport numerous holes to the cocatalyst, which enhanced the charge utilization efficiency at 1.23 V versus the reversible hydrogen electrode (RHE) to a large extent. Besides, a noteworthy fact is that Zr doping increased the number of active FeIVO states, which significantly contributed to the enhancement in current density. However, it led to a delayed onset potential because of the positively shifted surface states (r-SS and FeIVO). Evidently, the different surface state distributions between Fe2O3 and Zr:Fe2O3 gave rise to anisotropic charge transfer and recombination behavior in the composite photoanodes. This study gives extensive insight into the hole transfer route in composite photoanodes and reveals the surface state-tuning effects of dopants and cocatalysts, which are significant for a deep understanding of the surface states and optimal design of composite photoanodes via surface state modulation.

A 25 cm2 Solar Redox Flow Cell: Facing the Engineering Challenges of Upscaling

AbstractThe solar redox flow cell (SRFC) is an emerging technology that uses semiconductors to photocharge redox pairs, storing solar energy in electrochemical fuels and heat. Despite being in its infancy, significant efforts have been made in the development of high‐efficient materials and in understanding the fundamental processes. However, little attention has been given to device architecture and scalability, which may prove equally important in bringing this technology closer to commercialization. This work is the first attempt at upscaling SRFCs, proposing an innovative 25 cm2 photoactive‐area device: the SolarFlow25 cell. A computational fluid dynamics model is developed to implement design key features aiming at: maximizing light absorption by the semiconductor, ensuring effective diffusion and convection of redox species, and guaranteeing minimal electronic and ionic transport resistances. After being connected to a redox flow cell (RFC), the combined SRFC/RFC device is used to photocharge–discharge a ferrocyanide/anthraquinone (2,7‐AQDS) chemistry continuously. A nanostructured hematite (α‐Fe2O3) photoelectrode combined in series with a dye‐sensitized solar cell (DSSC) produces an unbiased photocurrent of ≈40 mA. The solar‐to‐output‐electricity‐efficiency remains stable at ≈0.44%, fourfold higher than any other reported hematite‐driven SRFC. The guidelines provided here are expected to help design and upscale future SRFC devices, making solar energy accessible in decentralized locations.

On the relevance of understanding and controlling the locations of dopants in hematite photoanodes for low-cost water splitting

Successful large-scale implementation of solar fuel technologies relies on cost, performance, and reliability of materials, devices, and infrastructures. Earth-abundant, low-cost, easily recyclable, and environmentally benign light absorbers are desired for renewable fuel generation technologies, such as solar photoelectrochemical (PEC) water splitting. Hematite is considered an ideal material for PEC oxygen evolution reaction, which is a critical component in the overall water splitting process for hydrogen fuel generation. However, intrinsic and operational limitations have prevented hematite-based PEC devices from reaching their highest theoretical solar-to-hydrogen efficiency of 15%–17%. Literature clearly shows that no single approach can eliminate these limitations. An overall fundamental understanding of the effect of dopant addition as well as their physical locations and functions within the photoelectrode, in both as-synthesized form and under operating conditions, is of critical importance to unleash the tremendous potentials of hematite-based PEC systems. In this short perspective, the concept of effective doping (i.e., increase of charge carrier density) up to the limit of dopant segregation at the grain boundaries to lower the charge recombination is discussed. Based on relevant theoretical and experimental data from the literature on the effects of surface-to-bulk doping as well as dopant segregation at the grain boundaries on hematite photoelectrode performance, we discuss here the views on the necessity of understanding these processes and their individual and synergistic effects to unravel a simple yet powerful approach to design and develop highly efficient hematite photoanodes for clean hydrogen generation using water and sunlight.

Ultrathin space charge layer in hematite photoelectrodes: A theoretical investigation.

The space charge layer in hematite photoelectrodes has been analyzed by means of Poisson-Boltzmann equations, the Stern model, and density functional theory, in view of its application for photoelectrochemical water oxidation. The width of the space charge layer can be smaller than ∼10 Å under experimental conditions. In this regime, a substantial part of the potential drop takes place in the Helmholtz layer, leading to important corrections to the Mott-Schottky behavior of the space charge layer capacitance. These results shed light on an unexpected regime of high photoelectrocatalytic efficiency, different from the classical picture of the electrochemical interface of a semiconducting photocatalyst, which is also amenable to direct study by quantum-mechanical atomistic simulations. Density functional theory has been used to calculate the band bending (BB) in the space charge layer in atomistic models of pristine stoichiometric and hydroxylated surfaces. These surface terminations display BBs of 0.14 and 0.49eV, respectively, with an increasing width of the space charge layer, however still in the sub-nanometer regime. This work shows that, at high doping, the width of the space charge layer of a hematite photoelectrode can become comparable with interatomic distances.

Function and Electronic Structure of the SnO2 Buffer Layer between the α-Fe2O3 Water Oxidation Photoelectrode and the Transparent Conducting Oxide Current Collector

The tin oxide buffer layer between the transparent conducting oxide current collector and the hematite photoelectrode causes considerable water oxidation enhancement of that electrode. The water ox...

Fluorine-surface-modified tin-doped hematite nanorod array photoelectrodes with enhanced water oxidation activity

Severe charge recombination and sluggish water oxidation reaction (OER) kinetics significantly limit the practical application of hematite in photoelectrochemical (PEC) water-splitting devices. In this study, fluorine-surface-modified tin-doped hematite (F/Sn:Fe2O3) photoelectrodes have been fabricated by a hydrothermal method incorporated impregnation annealing process. The grown FeOOH nanorods coated with NH4F solution are annealed first at 550 °C in the vacuum to modify the hematite surface and then at 750 °C in argon to promote the diffusion of tin atoms from the fluorine-doped tin oxide (FTO) glass substrate to the hematite structure. The synergistic effect of F-modification and Sn-doping on Fe2O3 electrode considerably enhances its PEC water oxidation performance, resulting in the highest photocurrent density of 3.64 mA cm−2 at 1.23 V vs. reversible hydrogen electrode (RHE) under AM 1.5 G illumination. Both effects increase the carrier concentration in the photoelectrode, which improves its transport efficiency. Moreover, the surface-localized F species promote the OER process on the electrode surface and improve the charge separation at the electrode/electrolyte interface by increasing its hole supply rate under the increased electric field. This work may open a new avenue for fabricating novel photoelectrodes with high PEC water splitting efficiency.

Grey hematite photoanodes decrease the onset potential in photoelectrochemical water oxidation

Photoelectrochemical (PEC) water splitting for solar energy conversion into chemical fuels has attracted intense research attention. The semiconductor hematite (α-Fe2O3), with its earth abundance, chemical stability, and efficient light harvesting, stands out as a promising photoanode material. Unfortunately, its electron affinity is too deep for overall water splitting, requiring additional bias. Interface engineering has been used to reduce the onset potential of hematite photoelectrode. Here we focus instead on energy band engineering hematite by shrinking the crystal lattice, and the water-splitting onset potential can be decreased from 1.14 to 0.61 V vs. the reversible hydrogen electrode. It is the lowest record reported for a pristine hematite photoanode without surface modification. X-ray absorption spectroscopy and magnetic properties suggest the redistribution of 3d electrons in the as-synthesized grey hematite electrode. Density function theory studies herein show that the smaller-lattice-constant hematite benefits from raised energy bands, which accounts for the reduced onset potential.

Selective converting surface states of hematite photoelectrodes to catalytic active sites

AbstractPhotoelectrochemical (PEC) water splitting is capable of converting solar energy to hydrogen and recombination loss at surface states inevitably compromises its efficiency. Selective conversion surface states to catalytic active sites would, therefore, have positive effect on photocurrent enhancement. We first adopted Zn(II) and Cr(III) to in situ passivate surface state of hydrothermally grown hematite electrodes. By plotting the photocurrent onset potential against the fraction of occupied adsorption site by Zn(II) and Cr(III), we found that surface state accounted for 0.1% of active sites of hematite electrodes. The fully passivated hematite possessed a reduced photocurrent onset potential by 0.12 V in comparison with that of raw hematite. Importantly, additional heat treatment of fully passivated hematite provided a great opportunity to selectively convert surface states to catalytic sites. For example, low temperature (120°C) treatment of Zn(II) passivated hematite was noted to exhibit almost doubled photocurrent at 1.1 VRHE in comparison with that of raw hematite. Our experimental results would be valuable for the insights into the electrode/electrolyte interface phenomenon and the strategies for PEC efficiency enhancement.

Enhanced photoelectrochemical water splitting efficiency of hematite (α-Fe2O3)-Based photoelectrode by the introduction of maghemite (γ-Fe2O3) nanoparticles

To enhance the photo-electrochemical performance of hematite photo-electrode, we designed a phase-junction configuration of α and γ-Fe2O3. By inserting maghemite (γ-Fe2O3) particles synthesized by reverse micelle deposition, which is for suppressing the phase transition from γ-Fe2O3 to α-Fe2O3, in between a hematite (α-Fe2O3) layer and fluorine-doped tin oxide (FTO) substrate, we could achieve a drastic improvement of the current density. We successfully confirmed using Raman spectroscopy that γ-Fe2O3 still remained after the annealing process performed at high temperature and the phase-junction configuration of α/γ-Fe2O3 was constructed. In addition, we could demonstrate using a time-resolved spectroscopic method and an electro-impedance spectroscopy measurement that the enhancement of the performance originated from the retardation of the recombination, resulting from the improvement of the charge separation efficiency.

Protection of hematite photoelectrodes by ALD-TiO2 capping

Iron (III) oxide, in the form of hematite (α-Fe2O3), is a n-type semiconductor which is photoactive in the visible spectral region. Therefore, use in photoelectrocatalysis and photoassisted water electrolysis may be suggested. For such implementations, stability of contacts with liquid phases is mandatory. Hematite is stable in alkaline media but less stable in acidic media. For the first time the coverage of porous photoactive Sn doped hematite by thin capping layers of TiO2, deposited by Atomic Layer Deposition (ALD) and its impact on photocurrent and chemical stability of hematite is shown. The nominal thicknesses of the TiO2 ALD coatings were 0.5, 2 and 7.5 nm. The presence of the TiO2 coatings was evidenced by X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy (HR-TEM) and scanning TEM coupled with energy dispersive X-ray (EDX) spectroscopy. HR-TEM analyses revealed that the TiO2 capping layers were amorphous and conformal. Exposure of uncovered hematite layers to 1 M sulfuric acid led to a nominal dissolution rate of 0.23 nm/h which was halved when a TiO2 ALD coating (7.5 nm thin) was applied. Due to mismatch of the valence band positions of the two semiconductors, photocurrents were strongly diminished as the capping layer thickness was increased. Post-calcination of as deposited ALD films on hematite resulted in an increase of photocurrent, which only exceeded photocurrents of pristine hematite when the ALD thickness was not more than 0.5 nm.

Photo-assisted electrodeposition of NiMoZn on hematite nanostructures and their photoelectrochemical application as photoanode for corrosion protection of stainless steel

In this study, hematite nanostructures (HN) were prepared on iron plates through anodization method, followed by the deposition of NiMoZn on the nanostructures by photo assisted electrodeposition method to produce NiMoZn/HN electrodes. The deposition time greatly effects on the photoeletrochemical performance of prepared photoelectrodes. In comparison with the bare hematite, the photocurrent density of NiMoZn/HN electrode was enhanced up to 5 times. In addition, the photocathodic protection characteristics of the NiMoZn/HN were evaluated by measuring the photo induced open circuit potential (OCP) and Tafel curves under light. The results showed that the photocurrent density of NiMoZn/HN samples increased from 0.11 to 0.51 mA cm−2 compared with the bare hematite sample. In addition, the photo induced OCP of the best NiMoZn/HN photoanode was decreased by about − 620 mV vs. Ag/AgCl with regards to photocathodic protection application. The results indicate that the NiMoZn photo-electrodeposition on the hematite photoelectrodes is a facile and efficient method for the protection of stainless steel from corrosion.