Comparative study of metal (Fe, Cu and Cr) doped ZnO nanostructure: Self-templated synthesis and application for photoelectrochemical water splitting

A thorough examination was undertaken to evaluate ZnO nanostructured films doped with transition metals (M = Fe, Cu, and Cr) and their respective functional attributes, emphasizing their potential applications in optical technology and electronic components. Both pure and M-doped ZnO nanostructured films were synthesized through a co-precipitation and spin coating procedure. Structural investigations revealed that all films exhibited hexagonal wurtzite formation. XRD findings highlighted evident evolution in the lattice parameters of prepared doped samples in comparison to the pure ones. The introduction of M doping led to modifications in various crystalline parameters of the host ZnO layers. Photocurrent density measurements illustrated a range from 2.5 µA/cm² for pristine ZnO to 25, 8 and 19 µA/cm² for Fe, Cu, and Cr-doped samples, respectively, showcasing distinct variations in performance. Notably, this study represents the first reported comparative analysis of the functional properties of three dopants spin coated in ZnO films. These distinctive results position the coated layers as promising candidates for novel optoelectronic applications.