Photoinduced Formation of Oxygen Vacancies on Mo-Incorporated WO₃ for Direct Oxidation of Benzene to Phenol by Air

Abstract

Photocatalysts with abundant oxygen vacancies (OVs) exhibit enhanced activity for the direct oxidation of benzene to phenol with O₂, owing to their superior O₂ activation and charge separation properties. However, OVs on metal oxide surfaces such as WO₃ are susceptible to healing by oxygen-containing reactants or intermediates, leading to their irreversible deactivation. Herein, we demonstrate that incorporating Mo into the WO₃ lattice effectively lowers the energy barrier for OV formation, promoting the dynamic formation of more abundant photoinduced OVs <i>in situ</i> on the surface during the photocatalytic reaction. These Mo-promoted photoinduced OVs are found to ensure the long-term sustainability of sufficient OVs under working conditions, enhancing photocatalytic performance and particularly its durability in the aerobic oxidation of benzene to phenol. These findings provide a straightforward strategy to overcome the issue of OV healing, enabling the sustainable operation of OV-rich photocatalysts for a range of emerging applications, even in O₂-involved redox reactions.