SIMULATION OF THE KINETICS OF CATHODIC SILVER DEPOSITION ON TI-TIO2 ELECTRODE SURFACE

The kinetics of silver deposition on the TiO2 surface is investigated with the aid of mathematical models involving both transport and elect rochemical processes that occur during metal electrodeposition on the semiconductor electrode surface. Rate constants for the nucleation and growth of silver species are evaluated. At the initial stages of the deposition, the current density is primarily influenced by the nucleat ion process at the electrode surface. At the later stages, the current -time dependence is controlled by the ion transport, by the stages of ion discharge at the electrode surface, by the effective concentration of growing centers, and by the properties of the space charge region in the semiconductor. The simulation has yielded the interval of poten tials where the metal deposition at the electrodes modified with preli minarily deposited silver proceeds more rapidly than at unmodified ele ctrodes.