Highly efficient photothermal catalysis of toluene over Co3O4/TiO2 p-n heterojunction: The crucial roles of interface defects and band structure

The unique physicochemical properties presented in the interface of composite oxides would result in some new features. Herein, MOx/TiO2 (M = Co, Mn, Ce, Cu, Fe) composites were constructed and successfully applied in the full spectrum light-assisted photothermal catalytic degradation of toluene. A unique p-n heterojunction with interface defects caused by lattice mismatch was constructed between TiO2 and Co3O4. The relationship between interface properties, band structure and photothermal catalytic performance based on experimental results and theoretical calculations had been studied comprehensively. The interfacial oxygen vacancy could improve oxygen mobility and provide more surface reactive oxygen species. The built-in electric field generated by electron transfer at the interface effectively promoted electron-hole pairs migration in the opposite direction. More active radicals and holes were provided to enhance the photothermal performance of CoTi catalyst. Furthermore, the possible reaction pathway of toluene and the photothermal synergy mechanism was proposed.