Electrochemical deposition of nanocrystalline zinc oxide at conductive diamond electrodes

The electrodeposition of zinc oxide thin films at diamond electrode surfaces has been investigated, using a chemical route whereby the electrochemical reduction of nitrate ion raises the local pH, causing the growth of zinc oxide onto the electrode surface. Growth parameters encompassing variation of solution concentration and temperature, along with the electrode potential, are investigated in order to establish the optimal conditions for electrodeposition. The deposits formed comprise small grain crystalline ZnO material and the deposition rate is dependent on the chemical termination and topography of the electrode surface. Deposition is found to be most rapid if the electrode is oxygen-terminated and occurs preferentially at the edges of the exposed crystal facets in the underlying diamond substrate.