Fe2O3 Photoanode Research Articles

Fe2O3 photoanodes: Photocorrosion protection by thin SnO2 and TiO2 films

The possibility of protection of Fe2O3 (hematite) against photocorrosion in aqueous electrolytes by thin layers of TiO2 and SnO2 deposited by ALD (atomic layer deposition), was investigated. Sn-doped hematite layers, as obtained in this study by aerosol pyrolysis had significant roughness and porosity. ALD is very successful in applying conformal films to such structures. The nominal coverage by ALD films was varied between 0.5 and 7.5 nm. The presence of the TiO2 and SnO2 films was evidenced by XPS. Photocurrents were strongly diminished as the capping layer thickness was increased. The Faradaic efficiency, f, of photocorrosion in acidic media (0.01 M H2SO4) was decreased from 0.026 to 0.014 and to 0.010 by capping with either a 2 nm thick overlayer of TiO2 or of SnO2, respectively. The latter had also a positive influence on the long term photocurrent stability.

Synthesis and the photoelectrochemical performance of Fe2O3 photoanode through pretreatment

The photo-electrochemical performance of hematite (α-Fe2O3) photoanode was evaluated and the preparation conditions were optimized in terms of maximizing the photoelectrochemical performances of the hematitephotoanodes. The photoelctro chemicalper for mances of hematite photoanode can be improved by the electrochemical surface pretreatment, and a possible mechanism was proposed to explain the reason for the improvement of photoelctro chemicalper for mances.

Creation of oxygen vacancies to activate Fe2O3 photoanode by simple solvothermal method for highly efficient photoelectrochemical water oxidation

Photoelectric chemical (PEC) decomposition of water is regarded as one of the most promising ways to convert solar energy into hydrogen energy, which has attracted extensive attention from researchers at home and abroad. Among the numerous photoanode materials, α-Fe2O3 is considered to be one of the most promising photocatalytic materials. However, due to the poor conductivity, short photogenerated charge life and high overpotential of water oxidation reaction, the development and application of α-Fe2O3 is seriously hindered. Recently, the introduction of oxygen vacancies is an effective method to improve the efficiency of α-Fe2O3 photoelectric conversion. In this work, oxygen vacancy was introduced in Fe2O3 photoanode by simple solvothermal method with ethylene glycol as solvent at 160 °C. The photoelectric catalytic activity of eg-Fe2O3 was significantly improved for solvothermal process. At 0.186 VSCE (1.23 VRHE), the photocurrent density of eg-Fe2O3 photoanode could reach 2.8 mA/cm2, which is 1–2 orders of magnitude higher than that of pristine Fe2O3 photoanode (0.1 mA/cm2). XPS test results show that the solvothermal process with ethylene glycol at 160 °C introduces oxygen vacancy to Fe2O3 photoanode. The tests of electrochemical impedance spectroscopy and photoelectrochemical impedance spectroscopy indicate that the introduction of the oxygen vacancy significantly improve the conductivity of the Fe2O3 photoanode and reduces the resistance of charge transmission between the electrode catalytic material and the electrolyte, which are the main reasons for the improvement of photoelectric water oxidation activity. This work provides a new method for improving the photoelectrochemical water oxidation by iron oxide photoanode.

Synergetic integration of passivation layer and oxygen vacancy on hematite nanoarrays for boosted photoelectrochemical water oxidation

To seek effective strategies that improve the photoelectrochemical water oxidation performance of hematite (α-Fe2O3) photoanodes is still challenging owning to their abundant surface states and low charge transfer efficiency. Herein, a facile impregnation method with an annealing process was developed to synthesize MoO3 modified Fe2O3 photoanodes using the MoO3 layer as an effective passivation component to decrease surface states and thus to improve the charge separation and transfer process at the electrode/electrolyte interfaces. The oxygen vacancies were subsequently introduced to steer the electrical conductivity, and further to boost the charge separation and transfer. The optimized MoO3-x/Fe2O3-x photoanode displays a photocurrent density of 2.6 mA cm–2 at 1.23 V versus the reversible hydrogen electrode under AM 1.5 G irradiation, 2.2 times that of the Fe2O3 (1.2 mA cm–2). The synergetic integration of passivation layer and oxygen vacancies on photoelectrodes heralds an efficient paradigm for solar energy conversion.

Enhancing the water splitting performance via decorating Fe2O3 nanoarrays with oxygen-vacancy-rich Ni1-xFexS electrocatalyst

In this work, oxygen-vacancy-rich Ni1-xFexS electrocatalyst modified Fe2O3 nanoarrays photoanode (denoted as Ni1-xFexS/Fe2O3) has been prepared firstly through a facile dripping solution method and a sulfurized process. As-prepared Ni1-xFexS/Fe2O3 anode shows a very high photocurrent density of ∼3.48 mA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE) and a saturated photocurrent density of 7.03 mA/cm2 at 1.57 V vs. RHE in PEC water splitting, which is 2.5 times of Fe2O3 (1.38 mA/cm2 at 1.23 V vs. RHE and 2.98 mA/cm2 at 1.57 V vs. RHE, respectively). Moreover, the photocurrent onset potential shows a distinct negative shift of about 272 mV. The Ni1-xFexS/Fe2O3 photoanode is controllable to achieve superior PEC performance because of the synergistic effects of Ni1-xFexS electrocatalyst and oxygen vacancies. Since in situ formed Ni1-xFexS electrocatalyst not only increase electrochemical active surface area of electrode, but also dramatically decrease solid and electrolyte interface resistance as well as dramatically suppresses charge carrier recombination in Fe2O3 photoanodes. In the meanwhile, introduced the oxygen vacancies in a sulfurized process of Ni1-xFexS electrocatalyst serve as active sites for sufficient chemical reaction. Hence, our work testifies oxygen-vacancy-rich Ni1-xFexS not only act as a promising OER electrocatalyst, but also offers a new strategy to prepare efficient and low-cost PEC solar energy conversion devices.

Coupling effects of indium oxide layer on hematite enabling efficient photoelectrochemical water splitting

Hematite (α-Fe2O3) based nanomaterials are considered as the most promising photoelectrodes for solar water splitting. However, some inherent shortcomings like high density of surface states is still the critically challengeable issue. This paper reports the integration of In2O3 nanolayers (NLs) on the surface of worm-like Fe2O3 films to significantly improve the photoelectrochemical (PEC) water oxidation activity. The In2O3 NLs on the modified α-Fe2O3 photoelectrodes exhibit dual positive effects on PEC performance: i) acting as the passivation material to decrease surface electron-hole recombination losses; ii) constructing heterojunctions with Fe2O3 to facilitate efficient separation of surface charges and spatial transfer with extended lifetimes. The resulting treated Fe2O3 photoanode yields a current density of 3.4 mA cm―2 at 1.23 V vs. reversible hydrogen electrode and high incident photon-to-current efficiency of 80 % at 400 nm. These results may bring inspiration to introduce multifunctional modifiers on photoelectrodes that offer practically high-performance PEC applications.

Synergetic catalytic behavior of dual metal-organic framework coated hematite photoanode for photoelectrochemical water splitting performance

The performance of oxide photoanodes constructed with hematite (Fe2O3) nanostructures is among the best for low-cost photoelectrochemical water-splitting cells. However, due to limited light absorption capacity, a high photogenerated charge carrier recombination rate, and sluggish surface oxygen evolution reaction (OER) kinetic on the surface, the photocurrent density generated by bare hematite is lower than the theoretical value. To overcome these limitations, we fabricate hematite photoanodes with a dual metal–organic framework (MIL-88B@ZIF-67) coating, which greatly enhances light harvesting efficiency and the intrinsic charge carrier transport rate. Owing to these spectacular advantages, the optimized Fe2O3/MIL-88B@ZIF-67 photoanode affords a stable photocurrent density of 2.52 mA∙cm−2 at 1.23 V vs. a reversible hydrogen electrode (RHE) under one sun irradiation. The photocurrent density is significantly higher than that achieved with a bare Fe2O3 photoanode (0.27 mA∙cm−2). Most importantly, the cathodic shift of the Fe2O3/MIL-88B@ZIF-67 photoanode (119 mV) is larger than that of pristine Fe2O3. The measured incident photon-to-electron conversion efficiency of the Fe2O3/MIL-88B@ZIF-67 photoanode reaches 30.85% at 330 nm. A photocurrent decay of only 5% over 20 h indicates that the photoanode is also extraordinarily stable. We find that it is crucial to precisely control the number of MIL-88B@ZIF-67 coating layers to reduce the charge carrier recombination rate. We expect that our approach will be effective for the design of efficient and stable photoanodes for PEC water splitting.

Hole extraction and injection pathways constructed by the in situ growth of ultra-thin Fe-doped NiOOH Co-catalysts on a fluorine-doped α-Fe2O3 photoanode

Hematite can be used as an efficient photoanode for solar water oxidation, but its oxygen evolution kinetics are quite slow. Herein, we developed an efficient hole transport photoanode via the in situ growth of ultrathin Fe-doped NiOOH on fluorine-doped hematite arrays using a natural growth strategy. The resulting FeNiOOH/F–Fe2O3 photoanode showed a high charge separation and injection efficiency. It achieved a stable photocurrent density of 2.52 mA cm−2 at 1.23 V vs. RHE, which was approximately 4.1-fold higher than that of pristine α-Fe2O3. Systematic studies revealed that the excellent photoelectrochemical activity was due to heteroatom doping and interactions between the co-catalyst (FeNiOOH) and F–Fe2O3. Fe doping primarily changed the lattice strain of the co-catalyst, while F doping decreased surface charge recombination and enhanced the intrinsic conductivity of hematite by increasing the carrier density. An ultrathin, amorphous layer of FeNiOOH further accelerated photogenerated hole extraction and the water oxidation kinetics. This work provides a method to produce new, cost-effective photoanodes for clean hydrogen production.

Cu2+ and Y3+ co-doped effect on morphology, structural, optical and photoelectrochemical properties of Fe2O3 photoanode

Cu and Y co-doped hematite (α-Fe 2 O 3 ) nanostructured photoanodes with excellent optical properties were synthesized for photoelectrochemical water splitting (PWS) applications. The effects of the dopants on the crystal structure, morphology, and optical and chemical properties of the Fe 2 O 3 photoanodes were investigated. Structural and chemical analyses confirmed the substitution of Cu and Y ions into the Fe 2 O 3 nanostructures. With an increase in the Y dopant concentration, the bandgap of the photoanodes decreased from ~1.85 to ~1.35 eV. The dopants acted as charge contributors and enhanced the electron-hole densities of the photoanodes. The co-doped Fe 2 O 3 photoanodes showed higher photocurrents and hence higher incident light absorption capacities than did the undoped and Cu-doped samples. The α-Fe 2 O 3 photoelectrode co-doped with 0.3 mol% Y and 0.1% Cu showed the highest photocurrent density of ~0.44 mA/cm 2 , which is ~41 times of that of the undoped Fe 2 O 3 (0.01 mA/cm 2 ) photoanode and ~ 7 times of that of the 0.1 mol% Cu-doped α-Fe 2 O 3 photoanode. Furthermore, the Cu-doped photoanode showed a very low photocurrent density of 0.06 mA/cm 2 , which is only ~6 times of that of the undoped α-Fe 2 O 3 photoanode. The high photocurrents of the co-doped photoanodes can be attributed to their high electron donor densities and low electron-hole recombination rates. • Cu 2+ and Y 3+ co-doped Fe 2 O 3 nanostructures prepared by simple hydrothermal method • Dopant effect on morphology has been studied • The charge carrier generation and kinetics of the photoanodes were investigated • Optimized photoanode shows the maximum photocurrent density of ~0.45 mAcm −2

Unraveling the role of Ti3C2 MXene underlayer for enhanced photoelectrochemical water oxidation of hematite photoanodes

Hematite is regarded as a promising photoanode for photoelectrochemical (PEC) water splitting. However, the charge recombination occurred at the interface of FTO/hematite strictly limits the PEC performance of hematite. Herein, we reported a Ti3C2 MXene underlayer modified hematite (Ti–Fe2O3) photoanode via a simple drop-casting followed by hydrothermal and annealing processes. Owing to the bifunctional role of Ti3C2 MXene underlayer in improving the interfacial properties of FTO/hematite and providing Ti source for the construction of Fe2TiO5/Fe2O3 heterostructure in hematite nanostructure, the bulk and interfacial charge transfer dynamics of hematite are significantly enhanced, and consequently enhancing the PEC performance. Compared with the pristine hematite, the as-prepared Ti–Fe2O3 photoanode shows an increased photocurrent density from 0.80 mA/cm2 to 1.30 mA/cm2 at 1.23 V vs. RHE. Moreover, a further promoted PEC performance including a dramatically increased photocurrent density of 2.49 mA/cm2 at 1.23 V vs. RHE and an obviously lowered onset potential is achieved for the Ti–Fe2O3 sample after the subsequent surface F-treatment and the loading of FeNiOOH cocatalyst. Such results suggest that the introduction of Ti3C2 MXene underlayer is a facile but effective approach to improve the PEC water splitting activity of hematite.

Enhanced Photoelectrochemical Water Splitting at Hematite Photoanodes by Effect of a NiFe-Oxide co-Catalyst

Tandem photoelectrochemical cells (PECs), made up of a solid electrolyte membrane between two low-cost photoelectrodes, were investigated to produce “green” hydrogen by exploiting renewable solar energy. The assembly of the PEC consisted of an anionic solid polymer electrolyte membrane (gas separator) clamped between an n-type Fe2O3 photoanode and a p-type CuO photocathode. The semiconductors were deposited on fluorine-doped tin oxide (FTO) transparent substrates and the cell was investigated with the hematite surface directly exposed to a solar simulator. Ionomer dispersions obtained from the dissolution of commercial polymers in the appropriate solvents were employed as an ionic interface with the photoelectrodes. Thus, the overall photoelectrochemical water splitting occurred in two membrane-separated compartments, i.e., the oxygen evolution reaction (OER) at the anode and the hydrogen evolution reaction (HER) at the cathode. A cost-effective NiFeOx co-catalyst was deposited on the hematite photoanode surface and investigated as a surface catalytic enhancer in order to improve the OER kinetics, this reaction being the rate-determining step of the entire process. The co-catalyst was compared with other well-known OER electrocatalysts such as La0.6Sr0.4Fe0.8CoO3 (LSFCO) perovskite and IrRuOx. The Ni-Fe oxide was the most promising co-catalyst for the oxygen evolution in the anionic environment in terms of an enhanced PEC photocurrent and efficiency. The materials were physico-chemically characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM).

Functional principle of the synergistic effect of co-loaded Co-Pi and FeOOH on Fe2O3 photoanodes for photoelectrochemical water oxidation

The establishment of multi-component catalytic systems on Fe2O3 photoanodes presents considerable potential for significantly enhancing the performance of photoelectrochemical water splitting systems. In this study, we hydrothermally synthesized a Fe2O3 photoanode. In addition, d-FeOOH synthesized via dip-coating and hydrothermally prepared h-FeOOH were used as cocatalysts and their synergistic combinations with cobalt phosphate (Co-Pi) were investigated. The synergy between h-FeOOH and Co-Pi was remarkable, whereas that between d-FeOOH and Co-Pi was negligible. For example, the onset potentials of the Co-Pi/h-FeOOH and Co-Pi/d-FeOOH dual catalysts, were cathodically shifted by 270 and 170 mV, respectively. Moreover, the photocurrent density of the Co-Pi/h-FeOOH/Fe2O3 anode was significantly higher than that of the Co-Pi/d-FeOOH/Fe2O3 one. The synergistic effect of Co-Pi and h-FeOOH could be attributed to the significantly inhibited recombination of surface charges owing to the formation of a p-n junction between β-FeOOH and Fe2O3 and the large contact area between the granular h-FeOOH and Co-Pi. However, the thin amorphous FeOOH layer of the Co-Pi/d-FeOOH/Fe2O3 anode acted as a hole-transfer medium, and weakly promoted the kinetics of the charge transfer process.

Effect of the applied potential condition on the photocatalytic properties of Fe2O3|WO3 heterojunction films

Semiconductors heterojunction and potential application have been investigated as strategy to improve the catalytic processes performance. In this study, we investigated the photocurrent response of photoanodes composed of two different heterojunctions, i.e., Fe2O3|WO3 and WO3|Fe2O3, which were prepared directly on transparent and conductive glass substrate (fluorine-doped tin oxide or FTO-glass) by combining hydrothermal and drop-casting methods. From photoelectrochemical studies, the conduction band edge’s positions for each semiconductor were determined using the Butler–Gartner model. The heterojunction films were utilized as photoanode in photodegradation of Rhodamine B (RhB) dye in aqueous solution. Under polychromatic irradiation, superior performance was registered for FTO|WO3|Fe2O3 photoanode, reaching a RhB dye photodegradation around of 32% in 3 h. Moreover, we performed structural analyses, optical characterizations, and morphological property investigations using XRD, UV−Vis, and SEM techniques, respectively. Moreover, from the electrochemical studies, the superior photodegradation performance and photocurrent density for photoanode were registered for FTO|WO3|Fe2O3 film.

Enhanced PEC performance of hematite photoanode coupled with bimetallic oxyhydroxide NiFeOOH through a simple electroless method

The oxygen evolution reaction (OER) is an important bottleneck in the development of economical photoelectrodes. Herein, we firstly prepared bimetallic oxyhydroxide NiFeOOH layer on Fe2O3 photoanode through a simple electroless ligand-regulated oxidation method in order to build highly-matched semiconductor/cocatalyst interface. Benefited from the accelerated OER kinetics and low overpotential of bimetallic oxyhydroxide NiFeOOH, the resultant Fe2O3/NiFeOOH core-shell with strongly-bound heterojunction interface possesses better visible light absorption, enhanced photocurrent density (1.83 mA/cm2 at 1.23 VRHE) and good stability than bare Fe2O3 and semi-FeOOH or NiOOH decorated Fe2O3 photoanodes. We believe this work provides a new pathway for designing high-quality contact interface of various photoelectrode/catalyst.

Modulating Charge Separation Efficiency of Water Oxidation Photoanodes with Polyelectrolyte‐Assembled Interfacial Dipole Layers

AbstractThe charge separation efficiency of water oxidation photoanodes is modulated by depositing polyelectrolyte multilayers on their surface using layer‐by‐layer (LbL) assembly. The deposition of the polyelectrolyte multilayers of cationic poly(diallyldimethylammonium chloride) and anionic poly(styrene sulfonate) induces the formation of interfacial dipole layers on the surface of Fe2O3 and TiO2 photoanodes. The charge separation efficiency is modulated by tuning their magnitude and direction, which in turn can be achieved by controlling the number of bilayers and type of terminal polyelectrolytes, respectively. Specifically, the multilayers terminated with anionic poly(styrene sulfonate) exhibit a higher charge separation efficiency than those with cationic counterparts. Furthermore, the deposition of water oxidation molecular catalysts on top of interfacial dipole layers enables more efficient photoelectrochemical water oxidation. The approach exploiting the polyelectrolyte multilayers for improving the charge separation efficiency is effective regardless of pH and types of photoelectrodes. Considering the versatility of the LbL assembly, it is anticipated that this study will provide insights for the design and fabrication of efficient photoelectrodes.

Why Silicon Doping Accelerates Electron Polaron Diffusion in Hematite.

It is common that dopants enhance the conductivity of hematite Fe2O3, a popular photoanode, but the origin of the enhancement remains unclear. We establish the detailed mechanism by performing ab initio molecular dynamics simulations on electron polarons (EPs) in Fe2O3, obtained by an excess electron (e@EP) and a substitutional Si doping (Si@EP). For the first time, we observe EP hopping in both pristine and doped Fe2O3. We find that the neighboring Fe-Fe distance is the main driving force for the EP hopping, which occurs by the adiabatic charge transfer mechanism. The EP transport is determined by interplay of probabilities to reach a favorable configuration and to hop in that configuration. The hopping barrier decreases as the Fe-Fe distance decreases; however, hops can take place at larger Fe-Fe distances, because such configurations are easier to achieve. Importantly, we demonstrate that the Si dopant speeds up the EP transfer process by increasing the EP mobility. The origin can be ascribed to the following three factors: longer Fe-O bonds, smaller activation energies, and creation of low energy metastable EP states, in Si@EP Fe2O3 compared to e@EP Fe2O3. Interestingly, the EP hopping is random in e@EP Fe2O3, but quasi-random in Si@EP Fe2O3 with specific pathways promoting efficient EP transfer. These new findings greatly enrich the understanding of charge transport in Fe2O3 photoanodes.

Gradient Ti-doping in hematite photoanodes for enhanced photoelectrochemical performance

Hematite based photoanode is promising for solar water splitting while suffers from poor charge transport and separation efficiency that limit its practical application. Herein, we demonstrate two types gradient Ti-doped Fe2O3 photoanodes (Fe2O3–Ti (TiO2 deposited on the top of Fe2O3) and Ti–Fe2O3 (Fe2O3 on the top of TiO2)) to enhance charge transport and separation efficiency. Interestingly, Fe2O3–Ti and Ti–Fe2O3 photoanodes exhibit almost identical PEC performance with photocurrent of 1.50 mA cm−2 at 1.23 V vs. the reversible hydrogen electrode (RHE). However, the onset potential of Ti–Fe2O3 photoanode displays a cathodic shift of 80 mV comparing with that of Fe2O3–Ti photoanode. Moreover, the charge separation efficiencies on the surface (ηsurface) for Fe2O3–Ti and Ti–Fe2O3 can reach up to 96% at the higher potential range from 1.30 to 1.50 V vs. RHE, which are among the top values in the record of hematite-based photoanodes without co-cocatalyst. Further investigation demonstrates the forming of gradient Ti doping is not dependent on the location of the TiO2 layer, but mainly affected by the high annealing temperature. The enlarged contact area between hematite photoanode and the electrolyte, the improved charge separation efficiency, and increased charge carrier density are responsible for the enhanced PEC water splitting.

Photoelectrochemical water oxidation in α-Fe2O3 thin films enhanced by a controllable wet-chemical Ti-doping strategy and Co–Pi co-catalyst modification

The poor electrical conductivity, short hole diffusion length, and slow water oxidation reaction kinetics have severely limited the photoelectrochemical performance of the hematite (α-Fe2O3) photoanodes. In this paper, we report a facile wet-chemical approach to prepare the Ti-doping controllable hematite photoanode with subsequent Co–Pi electrocatalysts modification for solar water splitting. By optimizing the Ti-doping in Fe2O3, the Ti–Fe2O3 photoanodes can retain the primary morphology with the pristine Fe2O3 nanostructures, while simultaneously reducing the photogenerated charge carrier recombination rate in the films. Besides, by further decorating with Co–Pi co-catalysts on Ti–Fe2O3 surface, the formed Ti–Fe2O3/Co–Pi photoanode demonstrated an accelerated electrode/electrolyte kinetics during photoelectrochemical water oxidation reaction. As expected, the Ti–Fe2O3/Co–Pi photoanode produced an improved photocurrent density of 0.76 mA/cm2 at 1.23 V vs RHE, which is much higher than the photocurrent density of individual Fe2O3 (0.25 mA/cm2) and Ti–Fe2O3 photoanode (0.51 mA/cm2). This work provides a good insight for designing the composite photoanode to simultaneously enhance the charge transport and surface water oxidation kinetics for efficient solar fuel production.

Kinetic analysis of the synergistic effect of NaBH4 treatment and Co-Pi coating on Fe2O3 photoanodes for photoelectrochemical water oxidation

It is always a challenge to accelerate the surface reaction kinetics of α-Fe2O3 photoanode for photoelectrochemical (PEC) water splitting. Although the NaBH4 treatment and Co-Pi coating have exhibited a synergetic effect on reducing the onset potential and enhancing the photocurrent density of the Fe2O3 photoanode, their intrinsic interaction is still poorly understood. In this work, the synergetic effect has been well-explained by photoelectrochemical tests and the impedance spectroscopy. It is discovered that the surface states locating at the surface of Fe2O3 were mostly passivated by Co-Pi. However, excess surface states formed on the NaBH4 treated Fe2O3 photoanode at a relatively negative potential, which could not be passivated by Co-Pi. Those surface states acted as dual roles, that is, the hole transfer media between Co-Pi and the valence band of Fe2O3 as well as the block layer to prevent the recombination of the photogenerated electrons with Co-Pi. The intuitive result was that surface charge transfer speeded up and the charge recombination slowed down concurrently, which led to a reduced onset potential by 210 mV and an increased photocurrent in the PEC water splitting.

Magnetic field improved photoelectrochemical synthesis of 5,5′-azotetrazolate energetic salts and hydrogen in a hematite photoanode-based cell

The oxidative-coupling of 5-amino-1H-tetrazole (5AT) into 5,5′-azotetrazolate is the initial and critical step for the synthesis of 5,5′-azotetrazolate energetic salts. Unfortunately, there are several disadvantages of insufficient security and inconvenient purification in the conventional chemical-oxidation method of 5AT-coupling. Here, we report the solar simultaneous initiation of 5AT oxidative-coupling and hydrogen evolution in a photoelectrochemical (PEC) cell that consisted of a Ti doped Fe2O3 film (Ti–Fe2O3) photoanode and a Pt wire cathode. A stable Faradaic efficiency of 65% for the 5AT oxidative-coupling into 5,5′-azotetrazolate was achieved on the Ti–Fe2O3 film photoanode at room temperature. Simultaneously, hydrogen evolution was initiated on the Pt wire cathode by the photogenerated electrons of Ti–Fe2O3 film photoanode with about 99% Faradaic efficiency. Our investigations indictaed that the 5AT oxidative-coupling on the Ti–Fe2O3 photoanode is a holes-driven reaction which is kinetically favorable relative to water oxidation. Since the non-radiative recombination of electrons and holes on the Ti–Fe2O3 film photoanode could be reduced in the presence of a magnetic field, a higher synthesis efficiency of sodium 5,5′-azotetrazolate and hydrogen was achieved in the PEC cell under a magnetic field of 0.5 T. The present work provides a green approach to produce 5,5′-azotetrazolate salts and H2 simultaneously using solar energy with high efficiency.