Interfacial Cadmium Exchange in Equilibrated Aqueous Suspensions of Cadmium Sulphide: A Compartmental Analysis Assisted Radiotracer Study

摘要

Aqueous CdS suspensions are of interest as systems for photo-catalytic conversion of solar energy into chemical energy. Application of such systems requires long-term stability of CdS suspensions. This implies absence of net mass transfer to the aqueous phase from the solid CdS phase. Only an exchange - a balanced bi-directional transport- of cadmium and sulfide ions between CdS and its equilibrium solution may occur. The main objective of the work is the evaluation of the feasibility of the compartmental analysis assisted radio-tracer method for obtaining information on the kinetics of the bi-directional transport of cadmium across the solid/liquid interface in equilibrated acidic aqueous CdS suspensions. The influence of the composition of both the solid and solution has been investigated. Additionally, a tentative study of the effect of visible light illumination on the behavior of cadmium in CdS suspensions has been carried out as well.