Nanostructured ZnO films in forms of rod, plate and flower: Electrodeposition mechanisms and characterization

[Display omitted] •Electrosynthesis of ZnO nanostructures in the form of plate, rod and flower.•The role of type and concentration of supporting electrolytes on growth mechanism.•Detailed analysis of morphologies, in comparison with the Literature.•Nanoplate form of ZnO exhibits higher Fermi level and lower band gap. Uniformity and reproducibility of well-defined ZnO nanostructures are particularly important issues for fabrication and applications of these nanomaterials. In present study, we report selective morphology control during electrodeposition, by adjusting the hydroxyl generation rate and Zn(OH)2 deposition. In presence of remarkably high chloride concentration (0.3M) and −1.0V deposition potential, slow precipitation conditions were provided in 5mM Zn(NO3)2 solution. By doing so, we have obtained highly ordered, vertically aligned and uniformly spaced hexagon shaped nanoplates, on ITO surface. We have also investigated the mechanism for shifting the morphology from rod/plate to flower like structure of ZnO, for better understanding the reproducibility. For this reason, the influence of various supporting electrolytes (sodium/ammonium salts of acetate) has been investigated for interpretation of the influence of OH− concentration nearby the surface. From rod to plate and flower nanostructures, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis were realized for characterization, also the optical properties were studied.