Monoatomic oxygen fueled by oxygen vacancies governs the photothermocatalytic deep oxidation of toluene on Na-doped Co3O4

Reported herein is a study of oxygen vacancies (OVs) provoking the complete mineralization of toluene with Na-doped Co 3 O 4 as a photothermal catalyst. Doping Na + into Co 3 O 4 leads to distortion and charge disequilibrium in the Co 3 O 4 lattice, which generates abundant OVs. OVs work as specific centers to convert the absorbed O 2 molecules to the active oxygen species O - . Abundant O - radicals boost the outermost decomposition of toluene. Comparing the optimal Na-doped Co 3 O 4 (3%Na-Co 3 O 4 ) with the pristine Co 3 O 4 , despite almost the same removal efficiency (100%) on them, the 3%Na-Co 3 O 4 significantly outperforms Co 3 O 4 concerning the CO 2 yield in the photothermocatalytic oxidation of toluene under full-spectrum light irradiation (425 mW/cm 2 ; equilibrium temperature of 218 °C). A mineralization degree of 89.8% is achieved on 3%Na-Co 3 O 4 , which is 7-fold higher than that over Co 3 O 4 . The OVs also help render the high sustainability of 3%Na-Co 3 O 4, which maintains its outstanding performance even after 10 successive runs. • Abundant oxygen vacancies are generated after Na + doping into Co 3 O 4 . • Oxygen vacancies facilitate the adsorption and activation of O 2 to O - species. • O - radicals boost the outright decomposition of toluene to CO 2 and H 2 O.