Study of the Copper Electrodeposition on Titanium Electrodes

Abstract

The electrodeposition of copper on titanium electrodes was investigated using cyclic voltammetry and a potential step technique in 5x10-3 M CuSO4, 1M (NH4)2SO4 and pH values of 8, 9 and 10.3. Voltammetric analysis showed that the reaction is carried in two steps. The first corresponds to the reduction of Cu(NH3)2+ to Cu(NH3)2 +, possibly controlled by electronic transfer. The second corresponds to the reduction of Cu(NH3)2 + to Cu(0). The electrocrystallization mechanism and the coupled reactions are pH function. The overcrossing potential, Ec, remains constant, and may be related to the thermodynamic potential. The current transients confirmed nucleation and growth process. There is a possible kinetically controlled reaction occurring on the first Cu layer of the deposit or the Ti substrate and it will be confirmed on a later work by applying the appropriate model.