Studies on deposition of gold atomic clusters on to polycrystalline gold electrode from aqueous cetyl trimethyl ammonium bromide solutions

Abstract

Atomic (molecular) clusters, with less than 50-100 atoms (size <= 1.5 nm) are of special interest and exhibit novel and interesting properties due to quantum confinement of electrons and holes. These properties are quite different from those of gold nanoparticles and hence, understanding of electrochemical phase formation of gold atomic clusters assumes importance. In the present study, we report a detailed investigation of deposition of gold atomic clusters on to polycrystalline gold electrode from aqueous cationic surfactant solutions. The studies were undertaken over a wide range of potentials, covering both surface and bulk layer dissolution and deposition processes, by means of cyclic voltammetric and chronoamperometric techniques. Thus, gold atomic clusters are formed in both surface and bulk layer dissolution and deposition processes as evidenced by AFM, MALDI-TOF, XPS and DLS. Electrocatalytic activity has been performed by the electrochemical reduction of oxygen (O-2) on AuAC modified gold electrode in 0.1 M H2SO4.