Optical,structural and phase transition properties of Cu2O,CuO and Cu2O/CuO: Their photoelectrochemical sensor applications

Cu₂O and CuO provide a unique possibility to tune the band gap into the middle of the efficiency maximum for photoelectrochemical (PEC) and solar cell applications. Photoactive materials containing Cu₂O, CuO and Cu₂O/CuO have been prepared with high quality and stability in various compositions by an economic, simple and reliable electrodeposition (ED) method. These materials based on copper oxide have been characterized and compared using XRD, SEM, EDX, UV–Vis, PL, FTIR, Raman spectroscopy and electrochemical techniques. Based on the electrochemical production conditions; phase changes of photoactive materials and, at which conditions which phase or phases are present, were evaluated in detail. It was carried out that a full phase change from single-phase Cu₂O to single-phase CuO. The crystal dimensions expand as the cube-shaped Cu₂O transforms into CuO, crystal surface areas increase, crystal shapes change and turn gradually into flower-shaped crystals. Here, the band gap of copper oxide material can be altered within a broad scale by adjusting the element ratios. The semiconductors have been found to have direct band gap that is more preferred for solar energy applications. PEC performances of the copper oxide electrodes containing a different phase structure were determined, and the changes of PEC activities were examined comparatively. Copper oxide semiconductors have p-type conductivity and they act as photocathodes.     

Enhanced solar-driven water splitting of 1D core-shell Si/TiO2/ZnO nanopillars

In this work, 1D core-shell Si/metal oxide nanopillar (NP) photoanodes were synthesized for enhanced solar-driven water splitting processes. The core-shell structures were fabricated by atomic layer deposition of different metal oxides (TiO₂ and ZnO) onto Si NP, which were synthesized by metal-assisted chemical etching and nanosphere lithography. In order to characterize produced photoanodes various experimental techniques (SEM/TEM, XRD, Transmittance, Reflectance, Raman spectroscopy) were applied. Photoelectrochemical (PEC) water oxidation of produced photoanodes was studied. It was shown that composition of n-Si/TiO₂/ZnO NP exhibited enhanced photocurrents due to barrier effects. The enhanced PEC properties of core-shell Si/TiO₂/ZnO NP are caused by efficient charge separation of photogenerated electron-hole pairs in the TiO₂/ZnO shell and effective holes transfer to the shell-electrolyte interface. The superior photoelectrochemical performance of a photoanode based on core-shell Si/TiO₂/ZnO NP has been confirmed through electrochemical impedance spectroscopy and voltamperometric measurements under electrode irradiation. 1D core-shell Si/TiO₂/ZnO NP offer a new approach for preparing stable and highly efficient photoanodes for PEC water-splitting process.     

ZnO/Cu2O-decorated rGO: Heterojunction photoelectrode with improved solar water splitting performance

In present work, we report a facile fabrication process to improve the photoelectrochemical (PEC) performance of ZnO-based photoelectrodes. In order to achieve that, the Cu₂O nanocubes are cathodic-deposited on the as-prepared ZnO nanorods. Then rGO nanosheets are electrodeposited on the ZnO/Cu₂O heterostructures. The fabricated photoelectrodes are systematically studied in detail by different characterization techniques such as powder X-ray diffraction, micro-Raman, X-ray photoelectron spectroscopy, ultraviolet diffused reflectance spectroscopy and photoluminescence spectroscopy analysis. Morphologies of the fabricated photoelectrodes are investigated through electron microscopy in scanning and transmission mode. To evaluate the PEC performance of the fabricated photoelectrodes, the line scan voltammetry (LSV) measurement is performed using a three-electrode system in 0.5-M Na₂SO₄ electrolyte solution under stimulated light illumination at 100 mW/cm² from a 300-W Xenon Arc lamp coupled with an AM 1.5G filter using a three-electrode system. The photocurrent measurement demonstrates that the photoelectrodes based on ZnO/Cu₂O/rGO possess enhanced PEC performance compared to the pristine ZnO and ZnO/Cu₂O photoelectrodes. The photocurrent density of ZnO/Cu₂O/rGO-15 photoelectrode (10.11 mA/cm²) is ∼9 and ∼3 times higher than the photoelectrodes based on pristine ZnO (1.06 mA/cm²) and ZnO/Cu₂O (3.22 mA/cm²). The enhanced PEC performance of ZnO/Cu₂O/rGO photoelectrode is attributed to the excellent light absorption properties of Cu₂O and excellent catalytic and charge transport properties of rGO. Experimental results reveal that the proposed functional nanomaterials have a great potential in water splitting applications.     

Morphology selective electrodeposition of Cu2O microcrystals on ZnO nanotube arrays as efficient visible-light-driven photo-electrode

ZnO nanotube arrays were synthesized by the electrodeposition method and Cu₂O microcrystals with two kinds of morphologies were deposited on ZnO nanotube arrays successfully. At the deposition potential of −0.5 or −0.7 V, the cubic or spherical Cu₂O microcrystals were selectively deposited on ZnO nanotube arrays. By adjusting the deposition time, Cu₂O microcrystals with different sizes were obtained. The optical properties and photo-electrochemical performance of ZnO/Cu₂O were measured. The results showed that the as-prepared ZnO/Cu₂O heterojunction exhibited improved visible light absorption and enhanced photocurrent due to the excellent ability of Cu₂O microcrystals for harvesting visible light, and the effective separation and transfer of photo-generated electrons and holes owing to p-n junction between ZnO and Cu₂O. The experimental results demonstrate that the photo-electrochemical performance of ZnO/Cu₂O heterojunction nanotube arrays can be manipulated by controlling the morphology and the size of Cu₂O microcrystals.     

Preparation and characterization of copper oxide particles/polypyrrole (Cu2O/PPy) via electrochemical method: Application in direct ethanol fuel cell

The electrocatalytic performance of Polypyrrole-Copper oxide particles modified carbon paste electrode (Cu₂O/PPy/CPE) for electrocatalytic oxidation of ethanol was reported for the first time in alkaline media. The composite Cu₂O/PPy was prepared using a facile approach consisting on the deposition of Polypyrrole film on CPE using galvanostatic mode then followed by the deposition of Copper particles at a constant potential. Scanning electron spectroscopy (SEM), infrared spectroscopy (FTIR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were employed to characterize the structural and electrochemical properties of the Cu₂O/PPy/CPE and to explain the mechanism of electrooxidation of ethanol. The experimental parameters that influence the electrooxidation of ethanol were investigated and optimized. Our findings suggest that the electrodeposition of Copper particles on Polypyrrole film enhanced the catalytic activity towards the ethanol oxidation with a peak current density of 2.25 mA cm⁻² at 0.8 V vs Ag/AgCl, which is 2.6 times higher than the peak current density obtained by PPy/CPE electrode. It important to note that the saturation limit reaches a value of 5 M. To summarize, the good catalytic activity, stability and easy preparation make the Cu₂O/PPy composite as an excellent electrocatalyst for ethanol oxidation.     

Cu2O as an emerging photocathode for solar water splitting - A status review

Recently, cuprous oxide (Cu₂O) based photocathodes have gained research attention for hydrogen (H₂) production through photoelectrochemical (PEC) water splitting reactions due to marginally lower synthesis cost and low energy intensity fabrication processes. Unique properties of Cu₂O, such as tunable bandgap, appropriate band edge potentials with water redox levels and non-toxic nature makes it beneficial for PEC applications. Cuprite is mainly studied under visible light to facilitate enhanced H₂ gas production upon illumination. However, notoriously photocorrosion degrades the PEC performance and restricts the photoactivity of Cu₂O. Moreover, because of the redox potentials lies within the band gap of Cu₂O; self-photocorrosion or self-oxidation upon illumination is unavoidable. Improvement in the Cu₂O photocathodes was achieved by finding elegant solutions such as forming thin heterojunction layers by atomic layer deposition (ALD) as well other methods, co-catalyst deposition, tuning crystal facets and surface modifications with different synthetic methods. In this review, we discuss the improvements in Cu₂O photocathodes achieved over the years for enhanced H₂ production with recently studied photocathodes.     

Structural and hydrogenation studies of ZnO and Mg doped ZnO nanowires

In this work, Mg doped zinc oxide (Mg_xZn_1−xO, x = 5, 10 and 20 at. %) nanowires were successfully prepared by two step process. Initially, ZnO nanowires were grown by thermal evaporation of Zn powder under oxygen atmosphere. Mg powder was doped in as grown ZnO through solid state diffusion at low temperature. Energy dispersive x-ray spectroscopy (EDAX), transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV–Visible absorption spectra analysis reveals that the Mg doping on ZnO nanowires induces lattice strain in ZnO. Rietveld analysis of XRD data confirms the wurtzite structure and a continuous compaction of the lattice (in particular, the c-axis parameter) as x increases. The hydrogenation properties of ZnO nanowires and Mg doped ZnO (Mg_xZn_1−xO, x = 0, 5, 10 and 20 at. %) nanowires were studied. The hydrogenated samples were further investigated through XRD and Fourier transform infrared spectroscopy (FTIR). The hydrogen storage capacity of as grown ZnO nanowires has been estimated to be 0.57 wt. % H₂ at room temperature. However, the hydrogen storage capacity gets increased to ∼1 wt. % upon doping ZnO with 10 at. % Mg. Further increase in Mg concentration decreases the hydrogen storage capacity of ZnO nanowires. Thus for 20 at. % Mg doped ZnO; the hydrogen absorption capacity gets decreased from ∼1 wt. % to 0.74 wt. %. The mechanism of hydrogen storage in ZnO nanowires and Mg doped samples of ZnO has been discussed.     

Effect of alkaline-doping on photoelectrochemical activity of electrodeposited cuprous oxide films

P-type Cu₂O films with alkaline ions (Li⁺, Na⁺ and K⁺) of unintentional dopants on indium tin oxide coated glass substrate are successfully fabricated via a simple electrodeposition method for photoelectrochemical (PEC) hydrogen generation. The SEM and XRD analysis show the as-grown films with the pyramid-like morphology and cubic structure, and the composition of alkaline-doped Cu₂O films are examined using XPS spectroscopy to demonstrate the substitution of alkaline ions in the Cu₂O lattice. The optical analyses, including the absorbance and low-temperature photoluminescence spectra, confirm a bandgap of 2.3 eV and the presence of structural defects in alkaline-doped Cu₂O films. The Mott-Schottky plot shows the flat band potentials of the alkaline-doped Cu₂O films to be approximately ?0.1 V and the hole concentrations in the order of 10¹⁷ cm^?3. Significantly, the Cu₂O:Li film photocathode exhibits a higher photocurrent of ?2.2 mA cm^?2 at a potential of ?0.6 V vs Ag/AgCl which are greater than those of Cu₂O:K and Cu₂O:Na films due to greater preferred orientation degrees along (111) and less structural defects, because the ionic radii of Cu and Li is similar. These results demonstrate the great potential of alkaline doped Cu₂O films in solar-related applications.     

Directed electrochemical synthesis of ZnO/PDMcT core/shell nanorod arrays with enhanced photoelectrochemical properties

In this paper, we demonstrate a simple two-step electrochemical deposition strategy for synthesizing ZnO/Poly(2,5-dimercapto-1,3,4-thiadiazole) (PDMcT) core/shell nanorod arrays. The as-synthesized ZnO/PDMcT samples are characterized by Fourier-transform infrared (FTIR), Raman spectroscopy, power X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The ZnO/PDMcT nanorod arrays are found to exhibit significantly enhanced photocurrent density in photoelectrochemical cell applications as compared to the prinstine ZnO nanorod arrays.     

Thin film deposition of Cu2O and application for solar cells

Deposition conditions of cuprous oxide (Cu₂O) thin films on glass substrates and nitrogen doping into Cu₂O were studied by using reactive radio-frequency magnetron sputtering method. The effects of defect passivation by crown-ether cyanide treatment, which simply involves immersion in KCN solutions containing 18-crown-6 followed by rinse, were also studied. By the crown-ether cyanide treatment, the luminescence intensity due to the near-band-edge emission of Cu₂O at around 680 nm was enhanced, and the hole density was increased from 10¹⁶ to 10¹⁷ cm⁻³. Finally, polycrystalline p-Cu₂O/n-ZnO heterojunctions were grown for use in solar cells. Two deposition sequences were studied, ZnO deposited on Cu₂O and Cu₂O deposited on ZnO. It was found that the crystallographic orientation and current–voltage characteristics of the heterojunction were significantly influenced by the deposition sequence, both being far superior for the heterojunction with structure Cu₂O on ZnO than for the inverse structure. We successfully obtained a photoresponse for the first time in the deposited thin film of Cu₂O/ZnO.     

A suitable deposition method of CdS for high performance CdS-sensitized ZnO electrodes: Sequential chemical bath deposition

A suitable deposition method of CdS is necessary for the high performance CdS-sensitized ZnO electrodes. In this paper, chemical bath deposition (CBD) and sequential chemical bath deposition (S-CBD) methods were used to deposit CdS on ZnO mesoporous films for ZnO/CdS electrodes. The analysis results of XRD patterns and UV-vis spectroscopy indicated that CBD deposition method leaded to the dissolving of ZnO mesoporous films in deposition solution and thickness reduction of ZnO/CdS electrodes. Absorption in visible region by the ZnO/CdS electrodes with CdS deposition by S-CBD was enhanced as deposition cycles increased due to the stability of ZnO mesoporous films in the S-CBD deposition solutions. The results of photocurrent-voltage (I-V) measurement showed that the performance of ZnO/CdS electrodes with CdS deposition by CBD first increased and then decreased as deposition time increased, and the greatest short-circuit current (J_sc) was obtained at the deposition time of 4 min. The performance of ZnO/CdS electrodes with CdS deposition by S-CBD increased as deposition cycles increased, and both open-circuit voltage (V_oc) and J_sc were greater than those electrodes with CdS deposition by CBD when the deposition cycles of S-CBD were 10 or greater. These results indicated that S-CBD is a more suitable method for high performance ZnO/CdS electrodes.     

Self-standing Co decorated Cu2O/CuS-based porous electrocatalyst for effective hydrogen evolution reaction in basic media

The self-standing Co decorated Cu₂O/CuS-based porous electrocatalyst was prepared with the help of simple electrodeposition and hydrothermal method. The structural characterizations of fabricated samples were performed with X-Ray diffraction spectroscopy and X-Ray photoelectron spectroscopy, while the morphology of catalysts was studied with the help of Field-Emission Spectroscopy and Transmission Electron Spectroscopy. The electrochemical performance of the hydrogen evolution reaction was checked in a basic electrolyte. The gradual increment in the electrochemical performance of Cu₂O was observed when it underwent sulfurization without and with Co precursor respectively. The best electrochemical performance for hydrogen evolution reaction with an overpotential of 150.29 mV to achieve a geometric current density of 10 mA/cm² was observed for the Cu₂O sample sulfurized with Co precursor. The results of different characterizations suggested that the improved electrochemical performance could be attributed to the increased intrinsic activity and surface porosity of the electrocatalyst after sulfurization.     

Fabrication of cost-effective non-noble metal supported on conducting polymer composite such as copper/polypyrrole graphene oxide (Cu2O/PPy–GO) as an anode catalyst for methanol oxidation in DMFC

Cost-effective non-noble metal catalysts are of key significance to the successful use of direct methanol fuel cells (DMFCs) for electricity generation. Herein, cuprous oxide nanoparticles (Cu₂O NPs) supported graphene oxide (GO), polypyrrole (PPy) and polypyrrole–graphene oxide (PPy–GO) matrices were prepared using borohydride reduction method. The prepared catalysts were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Vis spectra, Zeta potential and transmission electron microscopy (TEM). The elemental analysis of the composites was done by energy dispersive X-ray spectroscopy (EDX). Cu₂O NPs were homogeneously dispersed and strongly anchored on the PPy grafted GO matrix and this was examined through morphological analysis. The Cu₂O/PPy–GO (80:10:10) NPs exhibited noticeable improvement in electrochemical performance in comparison to pure graphene oxide (GO) and pure PPy supported Cu₂O NPs catalyst and revealed the peak current density of 300 μA cm^?2 at +0.68 V. The Cu₂O/PPy–GO system demonstrated higher current density and also exhibited greater stability in comparison to the commercial Pt–Ru/C catalyst as characterized by chronoamperometry (CA) analysis. This prospective nano-catalyst showed higher I_F/I_B ratio (26%, 8.6% and 19%) compared to the corresponding catalyst systems of Cu₂O/GO, Cu₂O/PPy and Pt–Ru/C. In direct methanol fuel cell (DMFC), the efficiency of Cu₂O/PPy–GO nano-catalyst system as an anode catalyst for methanol oxidation reaction (MOR) was investigated and the result revealed a maximum current density of 155 mA cm^?2 at +0.2 V and power density of 31 mW cm^?2. Hence, Cu₂O/PPy–GO NPs are a cost-effective alternative for Pt–Ru/C system to execute practical application in DMFC.     

Preparations of different ZnO nanostructures on TiO2 nanotube via electrochemical method and its application in hydrogen production

In the present study, zinc oxide doped titanium dioxide nanotubes (ZnO/TiO₂-NTs) were designed by using electrochemical deposition method. Titanium dioxide nanotubes (TiO₂-NTs) were fabricated by anodization method. Nanostructured ZnO was deposited with various deposition times on TiO₂-NTs. The morphological, structural, optoelectronic properties of ZnO/TiO₂-NTs were examined in detail. The morphological and structural characterization of obtained electrodes was investigated with help of field emission scanning electron microscopy and X-ray diffraction. ZnO nanostructures with three different morphologies were obtained from nanotowers to nanoleafs. XRD results depicted that ZnO nanostructures have the high crystallinity with hexagonal wurtzite structure. The measurements of the contact angle were utilized to determine the wetting behavior of the obtained surface of materials. Electrochemical impedance spectroscopy measurement was used in 1 M KOH to investigate electrocatalytic behavior of the obtained materials towards hydrogen evolution reaction. Flat band potentials, as well as charge carrier densities, were determined by using Mott-Schottky analysis. The charge carrier densities were calculated as 1.06 × 10¹⁹ and 1.66 × 10²⁰ cm⁻³ for TiO₂-NTs and 30-ZnO/TiO₂-NTs, respectively. The energy consumption and energy efficiency were determined for hydrogen evolution on ZnO/TiO₂-NTs electrodes.     

Sulfonated polyether ether ketone and hydrated tin oxide proton conducting composites for direct methanol fuel cell applications

Composite membranes based on sulfonated polyether ether ketone (SPEEK) and hydrated tin oxide (SnO₂·nH₂O) were prepared and characterized. The formation of the composite substantially modified the properties of SPEEK in terms of durability and electrochemical performance. The structural and electrochemical performance of the samples were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, electrochemical impedance spectroscopy (EIS), water and methanol uptake (WU, MU), and direct methanol fuel cell (DMFC) tests. The polymer electrolyte membrane doped with 50 wt% SnO₂·n(H₂O) possess good proton transport characteristics, reduced methanol uptake and improved stability with respect to a reference unfilled membrane and it is then suitable for application as electrolyte in DMFCs.     

Decorating Cu2O with Ni-doped metal organic frameworks as efficient photocathodes for solar water splitting

Severe photocorrosion and fast photoexcited charges recombination hinder the application of Cu₂O in photoelectrochemical (PEC) water splitting. In this work, Ni-doped metal-organic frameworks is firstly applied to improve the performance of electrodeposited Cu₂O. A decorative layer of Ni-doped Cu₃(BTC)₂ (Ni-CuBTC) was in-suit constructed on Cu₂O through solvothermal followed by ion-exchange. Cu₂O/Ni-CuBTC photocathodes increase absorption edge to ∼800 nm, positive shift flat band position to 0.4 V, and decrease Tafel value to 74 mV/dec. These results confirm the decorative layer can extend light absorption, facilitate photoexcited charge separation and transfer, and enhance HER activity. A photocurrent density of −1.51 mA/cm² at 0 V_RHE is obtained with the decoration of Ni-CuBTC, which is 3.4 times of pristine Cu₂O photocathode. Here, the PEC water splitting performance of electrodeposited Cu₂O has been significantly improved with noble-metal-free decorations, which provides a new idea for solving the defects of Cu₂O based photocathode.     

Two dimensional Cu based nanocomposite materials for direct urea fuel cell

In this work, Cu₂O nanoparticles were successfully prepared onto the surface of two-dimensional graphitic carbon nitride (g-C₃N₄) by using a simple solution chemistry approach. An environment-friendly reducing agent, glucose, was used for the synthesis of Cu₂O NPs onto the surface of g-C₃N₄ without using any surfactant or additives. The surface composition, crystalline structure, morphology, as well as other properties have been investigated using XPS, XRD, SEM, FTIR, FESEM, EDS, etc. The electrochemical measurements of the prepared materials demonstrated that Cu₂O exhibited a weak oxidation activity towards urea, while g-C₃N₄ has no activity towards urea oxidation. The Cu₂O supported on the surface of g-C₃N₄ (Cu₂O-g-C₃N₄) demonstrated a significant activity towards urea oxidation that reached two times that of the unsupported one. The significant increase in the performance was related to the synergetic effect between the Cu₂O and g-C₃N₄ support. The prepared composite materials demonstrated high stability towards urea oxidation as confirmed from the stable current discharge for around 3 h without any noticeable degradation performance.     

Nanostructured SrTiO3 thin films sensitized by Cu2O for photoelectrochemical hydrogen generation

We prepared nanostructured thin films of pristine SrTiO₃, Cu₂O and SrTiO₃/Cu₂O heterojunction with varying the thickness of Cu₂O. SrTiO₃ and Cu₂O thin films were deposited on ITO (Sn:In₂O₃) glass substrate using sol–gel spin-coating technique and spray pyrolysis method respectively. Samples were characterized using XRD (X-ray diffractometry), SEM (Scanning electron microscopy), and UV–Visible absorption spectroscopy. Nanostructured thin films of pristine SrTiO₃, Cu₂O and SrTiO₃/Cu₂O heterojunction systems were used as photoelectrode in the Photoelectrochemical (PEC) cell for water splitting reaction. Maximum photocurrent density value of 2.44 mA cm⁻² at 0.95 V/SCE were observed for SrTiO₃/Cu₂O heterojunction photoelectrode with 454 nm thickness, which was approximately 34 times higher than pristine SrTiO₃ thin film. Increased photocurrent density observed for the heterojunction can be attributed to the improved conductivity and better separation of the photogenerated charge carriers at the SrTiO₃/Cu₂O interface.     

Highly efficient sputtered Ni-doped Cu2O photoelectrodes for solar hydrogen generation from water-splitting

Hydrogen gas can be converted to electricity through fuel cells and is considered as a friendly energy source. Herein, pure Cu₂O and Ni-doped Cu₂O thin films were deposited on glass substrates using the RF/DC-sputtering technique for hydrogen production via the photoelectrochemical (PEC) water-splitting process. The preferred orientation for pure and Ni-doped Cu₂O films was (111) crystallographic plane. The average nanograins size was decreased from 32.17 nm for pure to 10.40 nm through the doping process with Ni content. Field-emission scanning electron microscopy (FE-SEM) and ImageJ analysis showed that the pure Cu₂O and Ni-doped Cu₂O were composed of normal distribution of nanograins in a regular form. The optical bandgap of the Cu₂O film was decreased from 2.35 eV to 1.9 eV after doping with 2.6 wt% of Ni-dopants. The photoluminescence (PL) spectra for all the sputtered films were recorded at room temperature to examine the effect of Ni-dopants in the Cu₂O lattice. Pure and Ni-doped Cu₂O films were applied for PEC water splitting for hydrogen (H₂) production under white light and monochromatic illumination. The PEC studies displayed that increasing the Ni content up to 2.6 wt% in the pure Cu₂O films led to an increase in the photocurrent density to reach ?5.72 mA/cm². The optimum photoelectrode was studied for reproducibility, stability, and electrochemical impedance. The incident photon to current conversion efficiency (IPCE%) was 16.35% at 490 nm, and the applied bias photon to current conversion efficiency (ABPE%) was 0.90% at 0.65 V. Consequently, Ni-doped Cu₂O photoelectrodes are efficient and low-cost for practical and industrial solar H₂ production.     

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.