Physical vapour deposition fabrication of MoO₃-based photoanode for water splitting to generate hydrogen

MoO₃ thin film was fabricated on an indium tin oxide substrate using the physical vapor deposition technique. X-ray diffraction and scanning electron microscopy study to investigate surface morphology, grain size, and surface structure, which are critical for absorbing solar spectra in water splitting for hydrogen energy generation. Ultraviolet-visible spectroscopy was used to confirm the absorption of solar spectra and the percentage of transmittance. Fourier-transform infrared analysis provided the functional groups present in the deposited thin film. The Tauc plot was used to determine the thin-film band gap, which allowed for the analysis of charge carrier transitions from the conduction band to the valence band. Electrochemical impedance spectroscopy investigations confirmed the charge transfer processes to the counter electrode and electrolyte interfaces. The observed low curve for MoO₃ indicated low resistance and allowed efficient charge transfer. Linear sweep voltammetry analysis was used to measure photocurrent and solar light to hydrogen emission when the thin film was exposed to solar spectra. The thin film's observed hydrogen emission rate was 3731.74 mol g^-1 h^-1, and the STH% of MoO₃ was found to be 0.345% at 0.8 V. These findings highlight the promising potential of MoO₃ as a material for hydrogen energy generation using solar light.