Integrating photoelectrochemical semiconductor sensor for sulphide ion determination

A novel approach to the determination of small amounts of S2− in aqueous solution based on the photoelectrochemical dissolution of semiconductor metal sulphide deposit arising at the surface of semiconductor electrode via exchange reaction is proposed. The potentialities of this approach are demonstrated using coulometric CdO-based photoelectrochemical sensor, which operates in an accumulation mode and exhibits a linear dependence of analytical signal (photocharge) on S2− concentration in the range 3.4×10−6 to 4.4×10−9 M.