Electric double layer on renewable liquid (Cd-Ga) electrode in dimethylformamide solutions

The double-layer characteristics on a renewable liquid (Cd-Ga) electrode (0.3 at % Cd) in dimethylformamide (DMF) solutions of various electrolytes are studied by the methods of differential capacitance and open-circuit streaming electrode. The zero-charge potentials unaffected by specific adsorption of ions and the parameters characterizing the (Cd-Ga)-DMF chemisorptive interaction (chemisorption potential drop of solvent and two-dimensional pressure of chemisorbed DMF dipoles) are determined. The results are compared with similar results for the (Cd-Ga)/gamma-butyrolactone (GBL) interface. The energy of (Cd-Ga)-solvent chemisorptive interaction increases with the transition from GBL to DMF due to the increase in the donor number of solvent. The adsorbability of halide ions at the (Cd-Ga)/DMF interface is judged based on the PZC shift in 0.1 De solutions of LiCl, LiBr, and LiI with respect to the PZC in solutions of a surface-inactive electrolyte. On the (Cd-Ga)/DMF interface, the inverted series of surface activity of halide ions is observed. Whereas on Hg and Bi electrodes the surface activity increases in the series Cl- < Br- < I-, on the (Cd-Ga) electrode and also on Ga and (In-Ga) electrodes the activity varies in the inverted sequence I-aEuro' < Br- < Cl-.