Boosting photocatalytic activity of WO3 nanorods with tailored surface oxygen vacancies for selective alcohol oxidations

Abstract

Developing metal oxides with tailored surface oxygen vacancies is very important for heterogeneous photocatalysis. In this work, uniform WO3 nanorods with tailored surface oxygen vacancies were prepared by a facile hydrothermal route, which exhibited highly enhanced photocatalytic activity for selective oxidation of alcohols to corresponding ketones in water medium. The physicochemical structural properties of uniform WO3 nanorods have been characterized and correlated with their photocatalytic activities. Results indicated that the enhanced photocatalytic activity of uniform WO3 nanorods was ascribed to the synergistic effect of the following three aspects: firstly, the high surface area favored the adsorption and diffusion of alcohol molecules; secondly, the small crystallite size shortened the transfer distance of photoelectrons and thus facilitated the fast transfer of photoelectrons, thereby restrained the recombination rate of photoelectron-hole pairs; finally, the surface oxygen vacancies acted as the photoelectron sinks could capture photoelectrons and promote their separation from holes. Meanwhile, the uniform WO3 nanorods also demonstrated good stability owning to its stable crystal phase and robust morphological structure.