Electric double layer on a renewable liquid (CdGa) electrode in dimethyl sulfoxide solutions

The electric double layer (EDL) structure on a renewable liquid (CdGa) (0.3at.% Cd) electrode in solutions of surface-inactive electrolyte is studied in a solvent with a high donor number, namely, dimethyl sulfoxide (DMSO). The following parameters: the potential of zero charge (PZC) unaffected by specific adsorption of ions, the value of “corrected electrochemical work function”, and the potential drop due to chemisorption of solvent are obtained on (CdGa)/DMSO interface and are compared with analogous results on Hg/DMSO, (TlGa)/DMSO, (InGa)/DMSO, Ga/DMSO, (CdGa)/acetonitrile (AN), (CdGa)/gamma-butyrolactone (GBL), and (CdGa)/dimethylformamide (DMF) interfaces. The chemisorption of DMSO molecules in the Helmholtz layer shifts the potential of the (CdGa) electrode in the negative direction, which suggests that chemisorbed DMSO dipoles are oriented with their negative (oxygen) ends to the metal surface. It is found that the solvent chemisorption potential drop on the (CdGa) electrode increases in the series AN