Oxygen Vacancies Enriched Hollow Bi₂MoO₆ Microspheres for Efficient Photocatalytic Oxidation of Hydrocarbons

Abstract

Photocatalytic aerobic oxidation of hydrocarbons to ketones is an attractive route for synthesizing high-value-added chemicals. However, the main challenge of photocatalytic oxidation reactions is their low activity. Herein, hollow Bi2MoO6 microspheres were synthesized by a facile two-step synthesis route combining ethylene glycol solvothermal with postannealing treatment. In the photocatalytic aerobic oxidation of ethylbenzene to the corresponding ketones under visible light irradiation using O2 as an oxidant, the hollow Bi2MoO6 microspheres exhibit a record acetophenone production rate of 1.1 mmol g–1 h–1 with 90% selectivity. The photoactivity of oxygen vacancy-enriched Bi2MoO6 is 61 times higher than that of uncalcined Bi2MoO6, which can be attributed to the effective separation of photogenerated carriers and the abundant catalytic active sites (i.e., oxygen vacancies) on hollow Bi2MoO6 microspheres. This work provides more insights into understanding how to construct highly efficient and active visible-light-responsive photocatalysts for the aerobic oxidation of organic compounds.