Structure of the mercury/ethylene carbonate interface. Part 3.—Adsorption of thiourea

Abstract

The adsorption of thiourea at mercury from ethylene carbonate solutions containing 0.5 mol dm^–3 KPF₆ and varying amounts of thiourea has been studied by measuring the differential capacity of the polarisable interface as a function of potential. The data were analysed to obtain the surface excess of thiourea as a function of electrode potential and bulk concentration. The parameters characterising the adsorption isotherm are discussed in terms of the electrostatic model for dipole adsorption by Kir'yanov, Krylov and Damaskin. These parameters are also compared with those obtained previously for the adsorption of thiourea from water, methanol, formamide, and dimethylformamide.