Electrochemistry of gallium in thiocyanate solutions of high ionic strength

Abstract

Normal pulse staircase, and reverse pulse voltammetry together with polarography and double potential step chronocoulometry were employed to examine the electrode processes of Ga(III) at mercury electrodes in solutions containing NaSCN at 4 M ionic strength. Thiocyanate ions were found to catalyze the reduction of Ga(III) with the reaction order of 1. No faradaic evidence of and thiocyanate-induced adsorption of Ga(III) was found. The formal potential Ga(III)/Ga(0) was found to be −0.731 V vs. SCE (25°C, pH 2.0 4 M NaClO 4), and the formation constant β 2=[Ga(SCN) 2 +]/[Ga 3+][SCN −] 2 was determined under the same condtions, as log β 2=5.6±0.1.