Low-coordination site engineering promotes in situ generation of oxygen vacancies for photocatalytic aerobic oxidation

Pretreating WO 3 with H 2 O 2 solution (WO 3 -H 2 O 2 ) efficiently reduces the W-O coordination number on its surface. • Low-coordination site significantly lowers energy barrier for photoinduced oxygen vacancy (OV) formation. • Sufficient OVs are rapidly generated on the surface of WO 3 -H 2 O 2 under visible light irradiation. • These in-situ evolved OVs exhibit excellent performance and superior stability toward photocatalytic aerobic oxidation. • This work provides a simple yet effective strategy to address the issue of surface OV healing. Engineering abundant oxygen vacancies (OVs) in metal oxides is a promising strategy for photocatalytic aerobic oxidation. However, OVs on metal oxide surfaces, such as those on WO 3 , are prone to healing during photocatalytic reactions, particularly under O 2 -rich working conditions, often resulting in a significant and irreversible loss of catalytic activity. Herein, we demonstrate that engineering low-coordination W-O sites onto the WO 3 surface through H 2 O 2 pretreatment can effectively lower the energy barrier for the OV formation, thereby facilitating the in-situ evolution of abundant photoinduced OVs during the reaction. These in-situ generated OVs exhibit superior performance and robust stability in the photocatalytic oxidation of benzene to phenol when using air as the oxidant. Our findings provide an efficient approach for developing OV-rich photocatalysts that maintain high stability and long-term performance in oxygen-involved photocatalytic reactions. Download: Download high-res image (153KB) Download: Download full-size image