Preparation and enhanced visible-light photocatalytic H2-production activity of CdS quantum dots-sensitized Zn1−xCdxS solid solutionElectronic supplementary information (ESI) available: Nitrogen adsorption–desorption isotherms for ZnS and CdS QDs-sensitized Zn1−xCdxS solid solutions and electron dispersive X-ray (EDX) spectrum for Zn1−xCdxS solid solution with CdS quantum dots. See DOI: 10.1039/c0gc00236d

CdS quantum dot (QDs)-sensitized Zn1−xCdxS solid solutions were successfully prepared by a simple cation exchange using hydrothermally synthesized ZnS nanoparticles (NPs) and Cd(NO3)2as precursors. The prepared samples show especially high visible-light photocatalytic H2-production activity from aqueous solutions containing Na2SO3and 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. [ABSTRACT FROM AUTHOR]