Effect of halides on adsorption properties of polyether laprol 2402 C on copper and tin electrodes

Voltammetry and the EIS technique are applied to study the adsorption behaviour of polyether laprol 2402 C on Cu and Sn electrodes in strong acidic sulphate solutions containing different halides. Laprol exhibits no pronounced effect on the kinetics of Cu(II) reduction in halide-free solutions. In contrast, strong inhibitive adsorption takes place in the Sn/Sn(II) system. The specific adsorption of halides taking place on copper and tin electrodes results in different effects. In the case of a copper electrode, halides may act as bridging particles enhancing laprol adsorption, whereas the competitive adsorption is responsible for a partial suppression of laprol adsorption on a tin electrode. The above effects were found to increase in the sequence: Cl−<Br−<I−. The possible adsorption isotherms are discussed.