Specific adsorption of bromide and iodide ions on the (Cd-Ca)/dimethylformamide interface

The specific adsorption of bromide and iodide ions from mixed solutions [0.1 m M LiBr + 0.1 (1 - m) M LiBF4] and [0.1 m M LiI + 0.1 (1 - m)M LiBF4] in dimetylformamide (DMF) with the following fractures m of surface-active anion: 0, 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, and 1 is studied on a renewable liquid (Cd-Ga) electrode by means of an ac bridge. The data on the specific adsorption of Br- and I- anions can be quantitatively described by the Frumkin isotherm, the same as the data on Cl-. It is found that in contrast to Hg/DMF and Bi/DMF interfaces for which the adsorption energy of halide (Hal(-)) anions (Delta G (ads)) increases with the transition from Cl- to Br- and further to I-, on the (Cd-Ga)/DMF interface, the Delta G (ads) values increase in the inverted sequence I-< Br-< Cl-. It is found that the energy of (Cd-Ga) interaction with Hal(-) anions () also increases in the sequence I- < Br- < Cl-. The comparative analysis of the results on the Hal(-) adsorption on the (D<inverted exclamation>d-GD degrees)/DMF and (In-GD degrees)/DNF interfaces shows that the interaction energies metal-DMF and metal-Hal(-) correlate with one another. For (Cd-Ga) and (In-Ga) electrodes which have virtually the same energy of metal-DMF interaction, the corresponding values of and turn out to be close not only for Cl- but also for Br- and I-.