Engineering oxygen vacancies of 2D WO3 for visible-light-driven benzene hydroxylation with dioxygen

Abstract

Solar-driven benzene oxidation with dioxygen (O2) provides a green and sustainable alternative for phenol production, but the construction of heterogeneous photocatalysts remains a huge challenge for efficient conversion under visible light irradiation and ambient conditions. Herein, we reported a facile microwave assisted strategy for the defect engineering of two-dimensional (2D) tungsten oxide while well maintaining the original crystalline architecture. Abundant oxygen vacancies were constructed on the 2D tungsten oxide, which remarkably promoted photochemical (light harvesting, charge separation and transfer) and O2 activation behaviors, this promotion effect was further strengthened by the hybridization with Pt species with the formation of Schottky junction. The champion catalyst enabled a high phenol yield of 11.3% with a selectivity of 91% in the visible-light-driven benzene hydroxylation with atmospheric O2 at room temperature. The catalyst can be facilely recovered and reused with stable activity. The oxygen vacancies and Pt co-catalyst were demonstrated to play vital roles in the photocatalytic formation of the reactive oxygen species (hydroxyl radials, ·OH) for effective oxidation.