Electrochemical behavior of gold (I) in dimethylsulfoxide

The mechanism of gold electrodeposition in dimethylsulfoxide (DMSO) was investigated by cyclic voltammetry and chronoamperometry. Experimental results showed that the electrodeposition of gold (I) in DMSO was an irreversible process and controlled by the diffusion of [Au(PPh3)]+ on a gold working electrode. Chronoamperometric results provide direct evidence that gold electrodeposition in DMSO takes place through a progressive nucleation and diffusion-controlled 3D growth mechanism. The values of kinetic parameters and the nucleation kinetics are calculated. The gold deposits were studied by scanning electron microscopy (SEM). The morphology of the deposited gold layers depends on temperature. The SEM studies showed that the optimum temperatures were found to be in the range from 50 to 60 °C.

► The electrochemical behavior of Au(PPh3)+ ion was investigated in a system consisting of Au(PPh3)Cl, NH4Cl and DMSO at 60 °C.
► The electrochemical behavior of gold electrodeposition in DMSO bath is firstly analyzed using chronoamperometry techniques.
► The optimum temperatures were found to be in the range from 50 to 60 °C, at which smooth and bright deposits were obtained.