Enhancing photoelectrochemical water-splitting performance of ZnO nanostructured thin films with copper doping

A promising solution to the energy issue and environmental deterioration is to use solar energy for the generation of hydrogen fuel (H2) as a clean source of energy on a large scale. The main goal of this work includes the development of ZnO-based photoelectrodes for effective photoelectrochemical (PEC) water splitting which enables the synthesis of H2 in an environmentally acceptable manner. This study focuses on the manufacture of ZnO thin films via the utilization of cost effective Successive Ionic Layer Adsorption and Reaction (SILAR) approach. Herein, pure and Cu-doped ZnO films at different doping ratios from 2 wt% to 6 wt% were effectively prepared. The examination of the produced films' morphological, structural, optical, and chemical composition characteristics was conducted using atomic force microscopy (AFM), x-ray diffraction (XRD), UV-vis spectroscopy and energy dispersive x-ray spectroscopy (EDX) technique. For each sample, the PEC behaviours for green H2 production and the measurements acquired from impedance spectroscopy were also examined. In the PEC test, a 6% Cu electrode proved to have the best PEC performance whereas it exhibited a maximum current density of around 3.6 mA cm-2 in 0.3 M Na2SO4 electrolyte compared with the other electrodes.