INFLUENCE OF THIOUREA ON SILVER DEPOSITION - SPECTROSCOPIC INVESTIGATION

The interfacial behaviour of thiourea (TU) in perchloric acid solution s on glassy carbon electrodes during silver electrodeposition has been studied using surface enhanced Raman spectroscopy (SERS). The spectro scopic results are compared with those obtained on electrochemically a ctivated silver electrodes. Potential-dependent thiourea adsorption (o ccurring via sulphur) and ClO4- coadsorption an observed. No evidence for the adsorption of solution silver-thiourea complexes regardless of TU concentration was found. The time evolution of the TU SERS signals during the electroreduction of silver is a function of the crystallit e formation (nucleation) and stabilization. (C) 1998 Elsevier Science S.A. All rights reserved.