Photoexcited Hole‐Enabled Synthesis of Surface High‐Valent Cobalt‐Oxo Species with Water as the Oxygen Atom Source for Water Purification

High‐valent cobalt‐oxo species (CoIV=O) are key intermediates in catalytic chemistry but suffer a great challenge in their efficient and mild synthesis due to the strong electronic repulsion between the cobalt center and the oxygen ligand. Herein, we report a new approach to synthesizing surface CoIV=O on the Co3O4/BiVO4 (CoBi) catalyst via a photoexcited hole‐induced process using water as the oxygen atom source. The interfacial Co2+‐O‐Bi3+ bonds act as the atomic‐level channels to directionally transport photoexcited holes driven by the internal electric field effect. It has been found that H2O was photolyzed to cobalt‐coordinated hydroxyls that were turned to CoIV=O via a photoexcited hole‐induced deprotonation. The isotopic labeling experiments confirmed that the oxygen atom source of CoIV=O was derived from water rather than chlorite. A synergistic effect was formed between photocatalysis and transition metal‐catalyzed chlorite activation, which enhanced the degradation of sulfadiazine (SDZ) and elevated the conversion ratio of chlorite to ClO2 from 40% to 60%. The present work has elucidated the essential role of H2O and photoexcited holes in the formation of CoIV=O and provides a viable strategy to synthesize surface high‐valent metal species utilizing ubiquitous water and sunlight for water purification.