Zn-doped hematite modified by graphene-like WS2: A p-type semiconductor hybrid photocathode for water splitting to produce hydrogen

A p-type Zn-doped hematite (α-Fe₂O₃(Zn)) in spindle-shape with an acceptor density of ca. 4.21 × 10¹⁸ cm^?3 were synthesized by a facile hydrothermal method. After α-Fe₂O₃(Zn) was modified with graphene-like WS₂ (α-Fe₂O₃(Zn)/WS₂), the photoelectrochemical performances of the composite can be further enhanced. A photocell composed of the p-type α-Fe₂O₃(Zn)/WS₂ nanocomposite as photocathode and n-type α-Fe₂O₃ as photoanode was assembled to estimate the photocatalytic activity of α-Fe₂O₃(Zn)/WS₂. The amount of the hydrogen and oxygen produced from this tandem cell with the optimal electrodes under 2 h simulated solar light irradiation is 12.5 μmol and 4.3 μmol, respectively.     

Convex-nanorods of α-Fe2O3/CQDs heterojunction photoanode synthesized by a facile hydrothermal method for highly efficient water oxidation

Morphology controlling and surface modification of semiconductors is the key for efficient photoelectrochemical (PEC) water splitting systems. This work provides a new strategy for achieving morphology control and heterojunction construction simultaneously by one-step hydrothermal method. The α-Fe₂O₃/CQDs heterojunction photoanode with convex-nanorods morphology is successfully prepared by hydrothermal method in CQDs (Carbon Quantum Dots) aqueous contained iron precursor followed by low temperature annealing treatment. Compared with bare hematite photoanode, the α-Fe₂O₃/CQDs photoanode has 8.5 time higher photocurrent density (at 1.23 V vs. RHE) of 0.35 mA cm^?2 and a negative shift of onset potential about 300 mV. The enhanced photoelectrochemical response is attributed to the convex-nanorods which benefit higher absorbance of light and the formed α-Fe₂O₃/CQDs heterojunction, which can efficiently enhance the electron-hole separation and reduce the surface charge recombination. The morphology and properties of the sample were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fouriertrans form infrared spectroscopy (FTIR), UV–vis spectra, X-ray diffractometry (XRD), X-ray photoelectron spectra (XPS), and photoelectrical measurements.     

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 V_SCE (1.23 V_RHE), 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.     

Preparation and photocatalytic H2-production on α-Fe2O3 prepared by sol-gel

In this work, the hematite α-Fe₂O₃ was synthesized by sol-gel method and characterized by X-ray diffraction and optical properties. The XRD patterns realized at different temperatures, show that pure hematite is obtained above 500 °C. The diffuse reflectance gives respectively direct and indirect optical transitions at 2.17 and 2.04 eV, in agreement with the red color. The capacitance measurement of α-Fe₂O₃ indicates p type behavior with a conduction band (?1.14 V vs. SCE), more cathodic than the H₂ evolution (～?0.8 V vs. SCE). The oxide was successfully tested for the hydrogen production under visible irradiation (29 mW cm^?2). α-Fe₂O₃ is photo-electrochemically stable in alkaline medium by hole consumption reactions involving X^2? (= SO₃^2? and S₂O₃^2?) as hole scavengers. The best photocatalytic activity for H₂ production was obtained on α-Fe₂O₃, calcined at 500 °C, in (Na₂S₂O₃ 0.025 M, pH ～ 13), with an average evolution rate of 0.015 cm³ h^?1 (mg catalyst)^?1 and a quantum efficiency of 0.26%. The system shows a tendency toward saturation, due to the competitive reduction of end products with the water reduction and the cathodic shift of the H₂ potential.     

Comparison of hydrogen absorption in metallic and semiconductor single-walled Ge- and GeO2-doped carbon nanotubes

First-principles calculations were carried out to compare hydrogen absorption in pristine metallic and semiconductor carbon nanotubes (CNTs) with the situation in their Ge- and GeO₂-doped counterparts. We found out that the pristine carbon nanotubes have low absorption efficiency (?1.53 eV in the metallic, and ?2.06 eV in the semiconductor carbon nanotube). When Ge was doped into both carbon nanotubes, the hydrogen absorption was enhanced to ?5.29 eV in the metallic and ?3.99 eV in the semiconductor carbon nanotubes. Investigating the Partial density of states proved that there was considerable overlap between Ge 4p and hydrogen 1s orbitals in both CNTs. When CNTs were doped with GeO₂, hydrogen atoms were bound to oxygen atoms, due to high electronegativity of oxygen atom. The hydrogen absorption was found to be increased remarkably in the metallic carbon nanotube (?6.59 eV). In order to compare the binding energy of Ge and GeO₂ doped metallic and semiconductor carbon nanotubes, the partial density of states and the magnetization of the samples were studied.     

Photoelectrochemical water oxidation performance promoted by a cupric oxide-hematite heterojunction photoanode

Hematite is a promising material for photoelectrochemical (PEC) water oxidation due to its narrow bandgap and chemical stability in alkaline electrolytes. However, the PEC performance of hematite is known to be inhibited by a short carrier diffusion length and slow kinetics for the oxygen evolution process. The rational control of morphology, crystallinity, and interfacial charge transfer plays an important role in tuning the PEC performance of α-Fe₂O₃ photoelectrodes. In this study, different iron oxide nano/microstructures are synthesized by the sintering of iron sheets in air at different temperatures. The synergetic effect of the surface morphology and crystallinity on the photocurrent and onset potential of the photoanode is investigated. The coral-like structure with high index (104) facets prepared at a high temperature shows a decreased onset potential, suggesting a strong correlation between the onset potential and crystalline orientation. To further improve the photocurrent density of this hematite photoanode, cupric oxide-hematite heterostructures are explored. An obvious improvement in the photocurrent density is observed from 1.1 to 1.6 V. The resulting α-Fe₂O₃/CuO photoanode exhibits a photocurrent density of 1.5 mA cm⁻² at 1.6 V, 25% higher than that of the pristine hematite. The Mott-Schottky plot and EIS measurement indicate that the α-Fe₂O₃/CuO heterojunction facilitates the extraction of the accumulated holes in the hematite through a type-II band alignment and the CuO can serve as a catalyst for promoting the oxygen evolution reaction.     

Enhanced photocurrent by MOFs layer on Ti-doped α-Fe2O3 for PEC water oxidation

Low photocurrent density of hematite (α-Fe₂O₃) originating from the inherent defects usually hinders its application in photoelectrochemical (PEC) water oxidation. In this paper, the synergetic effect of increase of oxygen vacancies and in-situ constructing heterojunction by coating MOFs on the α-Fe₂O₃ nanoarrays gives rise to the boosted photocurrent of α-Fe₂O₃ from 0.25 mA/cm² to 2.1 mA/cm² at 1.23 V (vs. RHE). The results showed that the appropriate energy band structure engineered by the presence of MOFs layer not only facilitated the PEC water oxidation, but also enhanced the light absorption performance. With inducing oxygen vacancies in further, the intrinsic conductivity of photoanode can be well ameliorated. The value of carrier density is improved one order higher to promote charge transfer between the interfaces and raise the carrier separation efficiency as a result.     

Enhanced photoelectrochemical performance of an α-Fe2O3 nanorods photoanode with embedded nanocavities formed by helium ions implantation

Hematite is a prospective semiconductor in photoelectrochemical (PEC) water oxidation field due to its suitable bandgap for the solar spectrum absorption. Nevertheless, the low transfer and separation efficiency of the charge carriers are restricted by its diffusion length of hole which is 2–4 nm and further reduce the PEC performance. Here, we report an innovative method, by introducing nanocavities into the α-Fe₂O₃ nanorod arrays photoanodes through helium ions implantation, to improve the charge carriers' transfer and separation efficiency and further to enhance water oxidation performance. The result indicates that, the photocurrent density of nanocavities embedded α-Fe₂O₃ photoanode (S2-A sample) reaches 1.270 mA/cm² at 1.6 V vs. RHE which is 1-fold higher than that of the pristine α-Fe₂O₃ (0.688 mA/cm²) and the photocurrent density of S2-A sample reaches 0.652 mA/cm² at 1.23 V vs. RHE. In this work, the ion implantation combined with post annealing method is found to be a valid method to improve the photoelectrochemical performance, and it also can be further used to modify the other semiconductor photoelectrodes materials.     

Design of efficient Mn-doped α-Fe2O3/Ti-doped α-Fe2O3 homojunction for catalyzing photoelectrochemical water splitting

To produce clean chemical fuel of hydrogen efficiently, applying photocatalysts for conducting photoelectrochemical water splitting is indispensable. Hematite (α-Fe₂O₃) has been considered as one of the most effective photocatalysts for water oxidation due to excellent visible-light responses, high stability and source abundance properties, but low electrical conductivity and slow oxidation evolution kinetics limit its application. In this study, a novel α-Fe₂O₃ homojunction is constructed via doping Ti and Mn in two layers using two-step hydrothermal synthesis followed by one-step annealing process. Co-doping effect of Ti and Mn in α-Fe₂O₃ and growing sequence of Mn doped α-Fe₂O₃ (Mn:Fe₂O₃) and Ti doped α-Fe₂O₃ (Ti:Fe₂O₃) are also investigated to illustrate the efficient design of Mn:Fe₂O₃/Ti:Fe₂O₃ homojunction. The optimized Mn:Fe₂O₃/Ti:Fe₂O₃ electrode shows the highest photocurrent density of 2.10 mA/cm² at 1.60 V_RHE respectively comparing to those of 0.10, 1.20 and 0.22 mA/cm² for Ti:FeOOH, Ti:Fe₂O₃ and α-Fe₂O₃ electrodes. The outstanding performance of Mn:Fe₂O₃/Ti:Fe₂O₃ homojunction is attributed to the smaller charge-transfer resistance, higher carrier density, and less charge recombination. This work gives a rational design for hematite-based photocatalysts and successfully attains greatly improved photocatalytic ability for water oxidation. Development of homojunction using heteroatom doping in thus verified to be highly applicable on synthesizing promising photocatalysts.     

Electrodeposited zirconium-doped α-Fe2O3 thin film for photoelectrochemical water splitting

Nanostructured hematite thin films were doped with zirconium successfully using electrodeposition method for their implementation as photoanode in photoelectrochemical (PEC) cell for hydrogen generation. XRD, Raman, XPS, SEM and UV-visible spectroscopy techniques were used to characterize the thin films. Highest photocurrent density of 2.1 mA/cm² at 0.6 V/SCE was observed for 2.0 at.% Zr⁴⁺ doped α-Fe₂O₃ sample with solar to hydrogen conversion efficiency of 1.43%. Flatband potential (−0.74 V/SCE) and donor density (2.6 × 10²¹ cm⁻³) were found to be maximum for the same sample. These results suggest substantial potential of hematite thin films with controlled doping of zirconium in PEC water splitting applications.     

Band gap engineering of Gd and Co doped BiFeO3 and their application in hydrogen production through photoelectrochemical route

The present report deals with the synthesis of Gd and Co doped BiFeO₃ (BFO) i.e. Bi_1-xGd_xFe_1-yCo_yO₃ (BGFCO, x = 0.0, 0.1; y = 0, 0.05, 0.10, 0.20, 0.25) nanoparticles by sol–gel method. The co-doping leads to band gap engineering of BiFeO₃ with the band gap varying from 2.23 eV to 1.77 eV. The band gap engineering coupled with UV–Vis spectroscopy has been used to find the optimum material. The significant lowering in the band gap of the doped BFO is attributed to the deformation produced in Fe–O octahedron geometry as well as rearrangement in its molecular orbitals. The band gap engineering leads to materials with improved solar spectral response which in turn results in better harvesting of solar energy. X-ray diffraction (XRD) patterns indicate the formation of pure phase of BiFeO₃ and its doped variants. The surface morphologies and particle sizes of different compositions have been investigated through scanning electron microscope (SEM). The as synthesized BFO as well as its doped variants have been used as photoanodes for hydrogen production through photoelectrochemical (PEC) splitting of water. The optimum material Bi_0.9Gd_0.1Fe_0.75Co_0.25O₃ (BGFCO-25) with band gap of 1.77 eV has been used as photoanode having PEC configuration of 1 mol/L NaOH as the electrolyte solution and the Pt as cathode using 1.5 AM UV–Vis illumination. This has produced the photocurrent density of 2.03 mA/cm² and hydrogen production rate of 74.57 μmol cm^?2 h^?1. The maximum photo-conversion efficiency has been found to be 2.29% for BGFCO-25 which is higher than that of BFO in which it is 0.76%. This noteworthy enhancement in the photoelectrochemical properties is ascribed to narrowing of the band gap which improves the solar spectral response and allows the absorption of higher density of photons. The stability test of the photoanode has been done through chronoamperometry technique.     

Thermally oxidized iron oxide nanoarchitectures for hydrogen production by solar-induced water splitting

Thermally oxidized iron oxide (α-Fe₂O₃, Hematite) nanostructures are investigated as photoanodes that convert solar energy into hydrogen by splitting water. α-Fe₂O₃ is stable for water photo-oxidation, it has a favorable band gap energy and is a non-toxic common material. However, α-Fe₂O₃ photoanodes suffer from high loss due to electron-hole recombination; therefore nanoarchitectures with high aspect ratio that allows photons to be absorbed close to the photoanode/electrolyte interface are preferred. The thermal oxidation of iron is a simple way to produce nanostructured iron oxide electrodes. Different morphologies, aspect ratios, and oxide thicknesses result depending on the process parameters. Nanorod structures were obtained by annealing iron foils in oxygen rich atmosphere, whereas annealing in oxygen lean atmosphere resulted in nanocoral-like morphology. The nanorod-structured photoanodes achieved moderate photocurrent density of 0.9 mA/cm² while the nanocoral morphology achieved 2.6 mA/cm² (both at 1.8 V vs. the reversible hydrogen electrode). The effect of the oxidation process and oxide layer on performance is discussed.     

Electrodeposited Cr-Doped α-Fe2O3 thin films active for photoelectrochemical water splitting

Polycrystalline hematite (α-Fe₂O₃) Chromium (Cr)-doped thin films were electrodeposited on fluorine-doped tin oxide-coated glass substrates. The electrodeposition bath comprised an aqueous solution containing FeCl₃·6H₂O, NaCl, and H₂O₂.Chromium was added to the electrolyte at such a proportion that the Cr/(Cr + Fe) ratio remained within the 2–8 at. % range. The as-deposited films were subsequently annealed in air at 650 °C for 2 h. The structure and morphological characteristics of the undoped and Cr-doped α-Fe₂O₃ thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV–Vis spectroscopy. Cr doping led the main XRD lines to shift to lower angles, which mostly resulted from substituting Fe³⁺ for Cr⁴⁺ ions that leads to α-Fe₂O₃ lattice contraction. The SEM observations showed that the roughness and aspect of surfaces changed with the Cr doping level. The photoelectrochemical (PEC) performance of the α-Fe₂O₃ films was examined by chronoamperometry and linear sweep voltammetry techniques. The Cr-doped films exhibited greater photoelectrochemical activity than the undoped α-Fe₂O₃ thin films. The highest photocurrent density was obtained for the 8% Cr-doped α-Fe₂O₃ films in 1 M NaOH electrolyte. All the samples achieved their best IPCE at 400 nm. The IPCE values for the 8 at.% Cr-doped hematite films were 20-fold higher than that of the undoped sample.This Cr-doped hematite films ‘excellent photoelectrochemical performance was mainly attributed to improved charge carrier properties. Such high photoactivity was attributed to the large active surface area and increased donor density caused by increasing the Cr doping in the α-Fe₂O₃ films.     

Spray pyrolytically deposited nanoporous Ti doped hematite thin films for efficient photoelectrochemical splitting of water

Nanoporous hematite (α-Fe₂O₃) thin films doped with Ti⁴⁺ deposited by spray-pyrolysis were successfully used in photoelectrochemical splitting of water for solar hydrogen production. X-ray diffraction, field emission scanning electron microscopy, UV–visible absorption and photoelectrochemical studies have been performed on the undoped and Ti⁴⁺ doped hematite thin films. Morphology of α-Fe₂O₃ thin films was observed to be nanoporous, with increased porosity (pore size ∼12 to 20 nm) on increasing doping concentration. A significant decrease in the bandgap energy from 1.95 to 1.27 eV was found due to doping. α-Fe₂O₃ film doped with 0.02 M Ti⁴⁺ ions exhibited best solar to hydrogen conversion efficiency (photoconversion efficiency) of 1.38% at 0.5 V/SCE. Highest photocurrent densities of 0.34 mA/cm² at zero bias and 1.98 mA/cm² at 0.5 V/SCE were obtained by incorporating 0.02 M Ti⁴⁺ in α-Fe₂O₃, which are significantly larger than earlier reported values. Donor density (30.8 × 10²⁰ cm⁻³) and flatband potential (−1.01 V/SCE) obtained were also maximum for this sample. Hydrogen collected in 1 hr at Pt electrode with the best photoelectrode was 2.44 mL with 150 mW/cm² visible light source.     

Deep surface reconstruction of Co-based cocatalyst on Ti-doped α-Fe2O3 photoanode for highly efficient water oxidation

Transition metal-based cocatalysts play important roles in promoting the surface kinetics of hematite (α-Fe₂O₃) photoanode. However, their performances are restricted by the shallow reconstruction process for generating highly efficient metal oxyhydroxides, where the oxygen evolution reaction (OER) occurs. Therefore, a Brnsted base-regulated strategy is developed to promote the in situ surface reconstruction of cocatalysts on Ti-doped α-Fe₂O₃ (Ti–Fe₂O₃) under photoelectrochemical conditions. After deep surface reconstruction by electrochemical activation, the CoWO₄ cocatalyst decorated Ti–Fe₂O₃ photoanode (a-CoWO₄/Ti–Fe₂O₃) delivers a photocurrent density of 0.88 mA cm^?2 at 1.23 V_RHE, which is about 3.0 times of activated Ti–Fe₂O₃ (a-Ti-Fe₂O₃) and 1.5 times of activated CoO_x/Ti–Fe₂O₃. Tungstate promotes the surface reconstruction of cobalt-based cocatalyst, resulting in a significant increase in bulk charge separation efficiency (η_sep) and surface charge injection efficiency (η_inj). Moreover, the type-II heterojunction between CoWO₄-derived CoOOH and a-Ti-Fe₂O₃ drives the rapid separation and transfer of photogenerated electron-hole pairs, and enhances the performance of Ti–Fe₂O₃ photoanode.     

Effect of ferroelectric poling on the photoelectrochemical activity of hematite-BaTiO3 nanowire arrays

Ferroelectric α-Fe₂O₃/BaTiO₃ photoanodes (hematite/BT) were fabricated on FTO and FTO/TiO₂ substrates using a hydrothermal process and spin coating along with thermal treatments. The prepared hematite nanowires had length under 1 μm and the BT film was about 18 nm thick. SEM, TEM and XPS investigations prove the formation of α-Fe₂O₃/BaTiO₃ heterojunction structure. The ferroelectric poling of hematite/BT heterojunction was conducted both in propylene carbonate and in air. The photoelectrochemical performance of hematite/BT photoanodes is strongly influenced by the direction of ferroelectric polarization. The positive poling of the hematite/BT prepared on FTO/TiO₂ substrate produces a 40.4% photocurrent density enhancement, in comparison with not poled version of the sample. Electrochemical impedance spectroscopy measurements provided usefull information regarding the effect of ferroelectric polarization on the charge transfer kinetics at the photoanode/electrolyte interface.     

Hydrogen release from sodium borohydride by Fe2O3@nitrogen-doped carbon core-shell nanosheets as reasonable heterogeneous catalyst

Due to the high volumetric density and environmentally friendly hydrolysis products, sodium borohydride as a promising candidate for chemical hydrogen storage has been intensively employed, but it needed expensive noble metals or complicated materials or processes. In this work, a new type of catalyst with very simple synthetic route form available and low-cost precursors has been introduced for hydrolysis of sodium borohydride with high efficiency. Fe₂O₃ nanosheets were synthesized with a straightforward route using glucose, urea and ferric nitrate and then the core sheets were coated by nitrogen doped carbon material using citric acid and urea as carbon and nitrogen sources. The core-shell nanosheets have been well confirmed by TEM images. Moreover, the elemental compositions were fully addressed by XPS analysis. Because of the acidic and basic groups on the presented material, the catalyst showed excellent catalytic activity with hydrogen production rate of 637 mL (H₂) min⁻¹·g_cat ⁻¹. It is notable that the rate was calculated based on the whole amount of the catalyst, while in other reports the metal active sites have been employed for calculations. To find the most promising nanostructure of α-Fe₂O_3, influence of Fe₂O₃ morphology on the catalytic activity was also investigated.     

Photoactivity of MWCNTs modified α-Fe2O3 photoelectrode towards efficient solar water splitting

MWCNTs (Multiwalled Carbon Nanotubes) modified α-Fe₂O₃ (hematite) photoelectrodes have been investigated for their possible application in hydrogen generation via photoelectrochemical (PEC) splitting of water. Enhanced photoresponse seen in comparison to the pristine α-Fe₂O₃ films is credited to the effective charge facilitation and charge separation provided by MWCNT conducting support. 0.2 wt% MWCNTs modified α-Fe₂O₃ thin film exhibited the maximum photocurrent density of 2.8 mA/cm² at 0.75 V/SCE. Measured values of flat band potential, donor density, resistance, Applied bias photon-to-current efficiency (ABPE) and Incident-photon-to current-conversion efficiency (IPCE) support the observed enhancement in photocurrent.     

Understanding the positive effects of (Co–Pi) co-catalyst modification in inverse-opal structured α-Fe2O3-based photoelectrochemical cells

Recent studies found that Co–Pi as a co-catalyst is of great significance for water oxidation in photoelectrochemical (PEC) cell because it efficiently suppresses surface electron/hole recombination. Besides, it leads to a cathodic shift for the onset potential obviously. In this study, the synergic effect between inverse-opal structured α-Fe₂O₃ and cobalt–phosphate (Co–Pi) component is investigated. As expected, the photocurrent density of the novel Co–Pi/α-Fe₂O₃ photoanode shows a significant enhancement compared to that of bare inverse-opal structured α-Fe₂O₃ especially at low potential, which can be ascribed to the efficient charge separation by the introduction of Co–Pi and 3D nanostructure. Not only that, a dramatic decrease in dark current is also noticed after being Co–Pi modification. To explain this phenomenon, a mechanism study has been carried out by using a series of joint characterizations, including I/V curve feature, Mott–Schottky plot and impedance analysis. The results reveal that the Co–Pi modification in 3D α-Fe₂O₃ structure can also facilitate electron transport in skeleton structure. These findings make 3D nanostructure-based PEC with Co–Pi co-catalyst modification a more promising approach to generate hydrogen/oxygen from water splitting.     

Photo-electrocatalytic water oxidation based on an earth-abundant metallic semiconductor-molecule hybrid photoanode

A molecular catalyst containing earth-abundant, low-cost cobalt was integrated with α-Fe₂O₃ film electrode for photoelectrochemical water oxidation. Under illumination of LED (λ = 420 nm), the hybrid photoanode exhibits a 7-fold enhancement in photocurrent density relative to bare α-Fe₂O₃ in 0.1 M Na₂SO₄ at pH 7. Accompanied by the highly stable photocurrent, stoichiometric oxygen and hydrogen are generated with a faraday efficiency over 85% respectively for 4 h photolysis. With hydrogen peroxide (H₂O₂) serving as the hole scavenger, it demonstrated that integration with molecular catalyst can greatly prompt hole diffusion length of α-Fe₂O₃ and improve its charge transfer properties. Mechanistic study and stability test supports that highly efficient and stable molecular catalyst plays the crucial role in charge separation, which successfully inhibits electron-hole recombination, achieving great enhancement in photocurrent. Therefore, to assemble into a highly active semiconductor-molecule heterojunction for solar fuel generation, the core relies on an available strategy to design the robust, stable and practical catalytic center.