Black single-crystal TiO2 nanosheet array films with oxygen vacancy on {001} facets for boosting photocatalytic CO2 reduction

Black TiO2 nanosheet array films with oxygen vacancy on {001} facets were prepared by solid phase reaction with a mild aluminothermic reduction method. The oxygen vacancies increase the absorption of visible light and the separation efficiency of photogenerated electron-hole pairs. For the black TiO2 with oxygen vacancy prepared by annealing, only the oxygen vacancies on {001} facets boost the photocatalytic CO2 reduction, while these on {101} facets in a small number increase the recombination of photogenerated electrons and holes and inhibit the photocatalytic CO2 reduction performance. Meanwhile, the black TiO2 nanosheet array films with oxygen vacancy on {001} facets have a good photocatalytic CO2 reduction to CO with a reduction rate of 128.5 mu mol.g(-1).h(-1) under visible light irradiation, which is ascribed to the formation of oxygen vacancy and the synergistic effect of special unsaturated coordination Ti-5c atom improving the adsorption capacity of CO2 and increasing the reduction rate of CO2 to CO. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Black TiO2 nanosheet array films with oxygen vacancy on {001} facets were prepared by solid phase reaction with a mild aluminothermic reduction method. The films exhibit good photocatalytic CO2 reduction to CO under visible light irradiation, attributed to the formation of oxygen vacancy and the synergistic effect of special unsaturated coordination Ti-5c atom.