Effect of the morphology of cadmium sulfide films on the process of ion-exchange substitution at the interface with a lead salt solution

Resumo

Comparative data on the effect morphological features of core CdS films chemically precipitated from citrate, ethylenediamine, and citrate–ammonia reaction systems have on the intensity of heterogenic ion-exchange substitution when they come into contact with an aqueous lead salt solution are given. The key role of the initial adsorption stage in this process is revealed. Based on an analysis of the kinetic curves of lead accumulation in the initial film surface, it is shown that CdS layers that are obtained from a citrate–ammonia system and have the maximum specific surface (154.4 ± 0.2 m²/g) yield higher values (0.020 s^–1) of kinetic constant W₁ of the ion-exchange substitution rate.