Rational approach for expanding functionality of wurtzite rectangle nano-sheets based photoanode for improved photoelectrochemical water-splitting performance

Photoanodes possessing multifunctionality for efficient clean fuel generation have garnered significant attention. In this study, we present successful fabrication of tungsten-doped ZnO photoelectrodes, resulting in enhanced photoelectrochemical water-splitting performance. A single-step deposition process was employed to achieve thin films with excellent adhesion on FTO substrates, eliminating the need for post-annealing treatments. The addition of tungsten into the ZnO matrix extended the optical absorbance range of the thin films to the visible spectrum, leading to improved photoelectrochemical performance under visible light irradiation. At an applied potential of 0.85 V vs. RHE, the as-fabricated tungsten-doped ZnO thin films exhibited a remarkable photocurrent density of 5218 μA/cm², which was eight times higher than that of the undoped ZnO electrode. The incorporation of tungsten in the ZnO photoanode resulted in increased charge carrier density and enhanced visible light absorption, consequently elevating the photocurrent density.