TiO2 mesocrystal with exposed (001) facets and CdS quantum dots as an active visible photocatalyst for selective oxidation reactions

摘要

CdS quantum dots decorated TiO2 mesocrystals with exposed (001) facets were synthesized by solvothermal alcoholysis and subsequent ion-exchange. The as-prepared photocatalyst exhibited high activity and selectivity in selective oxidations of various alcohols to their corresponding aldehydes under visible light irradiation. The high photocatalytic efficiency could be ascribed to the CdS quantum dots with enhanced photosensitizing effect and CdS-TiO2 heterojunction, the mesoporous structure with high surface area, and the exposed (001) facets with high surface energy and large number of oxygen vacancies, which promoted the light-harvesting, photocatalyst activation by visible lights, photoelectron-hole separation, reactant molecule adsorption and activation. Moreover, it also showed strong durability owing to the excellent stability against structural collapse and either CdS leaching or CdS corrosion. (C) 2016 Elsevier B.V. All rights reserved.