Deposition of ZnO rods by electrochemically induced Hydrolysis

Journal article, 2014

Galvanostatic electrodeposition of zinc oxide on gold electrodes was studied. Depositions were made from KCl solutions using oxygen reduction for driving the pH induced precipitation. The main focus was the influence of current density on the morphology and density of the deposit. The size, shape and density of the zinc oxide layer were shown to strongly depend on the current density. With an average rod diameter of 82 nm and a rod density of 36 μm−2 optimal conditions were found at −1.41mAcm−2. The experimental results are discussed within the context of zinc oxide solubility and the near surface pH. For this purpose a simple model for surface pH is considered, based on concentration profiles of reaction products near an RDE and the speciation of zinc in aqueous solution.