SEQUENTIAL ELECTRODEPOSITION OF SILVER AND BISMUTH ON A GOLD SURFACE

Sequential electrodeposition of Ag and Bi from a single electrolyte on Au(111) was studied by means of voltammetry and ion scattering spectr oscopy (ISS). Silver was electrodeposited first under diffusion contro l. Subsequently, bismuth was deposited under potential sweep condition s. Underpotential deposition of Bi on the gold surface modified with f ive Ag monolayers takes place similar to the deposition on the Ag(111) electrode. The deposited Bi can be electrodissolved completely with A g remaining on the surface. However, the voltammetric characteristics of this process are different from the one in the case of Bi on the (1 11) surface of a silver single crystal. The ISS data suggest that this might be due to intermixing at the Ag/Bi interface occurring subseque nt to the formation of the initial Bi on Ag structure on Au(111).