Electrochemical preparation of p-type cupric and cuprous oxides on platinum and gold substrates from copper(II) solutions with various amino acids

p-Type cupric oxide has been deposited electrochemically on platinum and gold electrodes from Cu(II) solutions containing various amino acids, which is very attractive because the procedure is simple and the preparation of large-area film is possible. This indicates that the anodic deposition of CuO takes place simultaneously with the oxygen evolution and the extent of participation of each reaction depends on the stability and structure of Cu(II)- amino acid complex, pH, electrode potential, etc. The grain size of CuO obtained in the presence of glycine, which was estimated from the diffraction peak of (110), was found to be smallest (12 nm) among those acquired with various amino acids, suggesting that the electrodeposition of CuO from Cu(II)-Gly solution leads to the formation of a denser film. Furthermore, it was revealed that the CuO prepared here possesses a property like a p-type semiconductor. The photoelectrochemical reduction of CuO to Cu2O was confirmed by analysis with X-ray diffraction. (C) 2002 The Electrochemical Society.