Deposition and stability of metal ions on oxidized silicon surfaces: electrochemical correlation

Abstract

XPS is used to determine the chemical state of Au, Hg, Tl, Pb and Bi deposited from their corresponding aqueous solutions on oxidized silicon or gold surfaces. It is determined that Au and Hg, having positive electrochemical reduction potentials, deposit in their 0-valent state, but Tl, Pb and Bi, having small positive or negative electrochemical reduction potentials, deposit in their corresponding ionic states, confirming our previous hypothesis about the electrochemical correlation. Electrochemical deposition of Au from aqueous solutions on to silicon electrodes yields 0-valent Au on both (+) and (-) polarized electrodes, with the only difference that more gold is deposited on the negatively biased one.