In Situ Raman Spectroscopy of Anodic Films Formed on Copper and Silver in Sodium Hydroxide Solution

In situ Raman spectroscopy and cyclic voltammetry have been used simultaneously to study anodic film growth and dissolution on Cu and Ag in strongly alkaline solution. On copper, Cu/sub 2/O and another species, believed to be a hydroxide, were detected spectroscopically during anodic film formation. Raman spectra of electrochemically formed hydroxides on copper have not previously been reported. On silver, AgO was detected. Neither CuO nor Ag/sub 2/O was observed by Raman spectroscopy, although for certain potentials. AgO was apparently produced by photochemical conversion of Ag/sub 2/O. Experiments were performed using both the 488 nm line from an argon laser and the 647.1 nm line from a krypton laser. It was concluded that the detection of these thin film oxides was by spontaneous or resonant Raman scattering and did not involve surface enhanced Raman scattering (SERS).