Preparation and enhanced visible-light photocatalytic H2-production activity of CdS quantum dots-sensitized Zn1−xCdxS solid solution

Abstract

CdS quantum dot (QDs)-sensitized Zn_1−xCd_xS solid solutions were successfully prepared by a simple cation exchange using hydrothermally synthesized ZnS nanoparticles (NPs) and Cd(NO₃)₂ as precursors. The prepared samples show especially high visible-light photocatalytic H₂-production activity from aqueous solutions containing Na₂SO₃ and Na₂S as sacrificial reagents even without a Pt co-catalyst. It was found that this high visible-light photocatalytic H₂-production activity is attributed to the quantum size effect of CdS; the presence of CdS QDs alters the energy levels of the conduction and valence bands in the coupled semiconductor system, which favors the electron transfer and enhances photoactivity.