β-cyclodextrin decorated cds nanocrystals boosting the photocatalytic conversion of alcohols

Abstract

Regarding the utilization of semiconductor nanocrystals (NCs) in photocatalysis, the significant challenge is to eliminate the hindrance of decorated surface ligands on the photocarrier transport while maintaining their overall stability. Herein,we report a novel and stable catalyst comprising CdS NCs and surfacebound mono-(6-mercapto-6-deoxy)-β-cyclodextrin (HS-β-CD) molecules (denoted as CdS-CD), which could convert alcohols selectively into diols or aldehydes and H2 under visible light irradiation, with 100% atomutilization, using an aqueous medium as a green solvent. The decorated β-CD ligands did not only confer a good stability of CdS-CD in water but also showed a high host-guest affinity to the alcohol species, thereby, guaranteeing a close vicinity of alcohol molecules at the surface of CdS NCs and minimizing the hindrance of surface ligands on the photocarrier transport. As a result, the CdS-CD displayed much improved photocatalytic activity for the conversion of alcohols in aqueous media, compared with those of CdS-BF4 NCs.