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

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 in situ 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.