X-ray Photoelectron Spectroscopic Investigation of Dithizone Anion Adsorption at Silver and Copper Electrodes

X-ray photoelectron spectroscopy (XPS) has been used to Investigate the adsorption of dithizone anion (HDz-) on silver and copper electrode surfaces from pH 12 aqueous alkaline buffer solutions. The XPS data of adsorbed dithizone forms were acquired on electrodes whose potentials had been set at a range of potentials from -1.2 to +0.6 V (vs. Ag/AgCI) In solutions of HDz-. These spectra are presented along with those obtained from authentic samples of neutral dithizone, bls(1,5-diphenylformazan-3-yl) disulfide, 2,3-diphenyl-2,3-dihydrotetrazolium- 5-thlolate, silver(I) dithlzonate, and coppert 11) dlthizonate. The XPS data are Interpreted with respect to the nature of the surface species found at the electrode surfaces at different potentials, and the XPS data are correlated with the surface Raman behavior described previously.