ELECTRODEPOSITION OF HARD GOLD FROM ACIDIC SOLUTION - THE INFLUENCE OF SUBSTRATES

Hard gold deposition from acidic solution on Au, Cu, Pt, Ni, and glass y carbon rotating disk electrodes was studied using linear sweep volta mmetric (LSV) and chronoamperometric methods. A rotation rate-dependen t peak was found on LSV curves on various substrates. Such a peak aris es from an inhibition process involved in gold deposition. The mechani sm and kinetics of nucleation and crystal growth in the initial stages of gold deposition on different substrates were determined. Gold depo sition on Au, Cu, and Pt at more positive potentials proceeds via thre e-dimensional progressive nucleation and crystal growth of right-circu lar cones. Potential-dependent inhibition of crystal growth was also o bserved. A time-dependent partial inhibition of crystal growth was fou nd for deposition on Au, Ni, and glassy carbon electrodes at more nega tive potentials.