The Influence of Alkali Metal Cations on the Capacitance
of the Electrical Double Layer of the Gold Electrode
in Cyanide Solutions

N. A. Rogozhnikov and N. M. Zakharova

Institute of Solid State Chemistry and Mineral Processing, Siberian Division, Russian Academy of Sciences,
ul. Derzhavina 18, Novosibirsk, 630091 Russia

Received July 5, 1995

Abstract—The influence exerted by the nature of alkali cations on the capacitance of the electrical double layer
is studied at the gold electrode in solutions containing both indifferent anions and specifically adsorbed CN^–
ions. In solutions containing specifically nonadsorbed anions, the nature of alkali cations is found to affect the
measured value of the electrode capacitance at potentials more negative than –0.6 V (NHE). The light Li⁺ and
Na⁺ cations affect the capacitance by being specifically adsorbed at the electrode. The heavier K⁺ and Cs⁺ cat-
ions change the electrode properties by forming a surface alloy as a result of cathodic incorporation into the
metal. After introducing the CN ions, at E < –1.0 V, adsorption of the Li⁺ and Na⁺ cations enhances adsorption
of the cyanide ions; conversely, cathodic incorporation of the Cs⁺ ions inhibits this adsorption. Apparently, at
more positive potentials, the capacitance is principally affected by the cation incorporation into the dense layer
as a result of an interaction with the cyanide ions adsorbed specifically.

Pleiades Publishing home page | journal home page | top

If you have any problems with this server, contact webmaster.