Carbon and nitrogen co-doped In2O3 porous nanosheets with oxygen vacancies for remarkable photocatalytic CO2 conversion

Abstract

Photocatalytic CO2 reduction to sustainable products by utilizing solar energy has great prospects for development. However, most of the conventional catalysts have the disadvantages of inefficient, low visible light absorption, and poor product selectivity. For this reason, in this study, carbon and nitrogen co-doped In2O3 (C,N-In2O3) porous nanosheets with oxygen vacancies have been successfully prepared by pyrolyzing the as-prepared carbon-rich InOOH (C-InOOH) nanosheets precursor in an ammonia-helium mixture gas. The derived C,N-In2O3 photocatalyst possesses a mesoporous structure, large surface area, accelerated charge transfer and separation, and high visible-light absorption ability. The carbon and nitrogen co-doping produced proper surface defects (oxygen vacancies), which can facilitate CO2 adsorption and inhibit photogenerated charge recombination. As expected, an efficient CO2 photoreduction is achieved over the C,N-In2O3 sample with a CO production rate of 152 μmol h−1 g−1 and 80% selectivity together with an excellent stability. This study provided an efficient C,N co-doping strategy for fabricating high-active and stable photocatalysts, which could be applied to the conversion and utilization of solar energy in the future.