Black In 2 O 3− x nanosheets for efficient solar-driven reverse water-gas shift reaction

Increasing the number of surface-active sites and light-harvesting capability of catalysts by regulating their electronic structures is critical for solar-driven reactions. Herein, we report an oxygen-defective rich catalyst, black In2O3-x nanosheets, as efficient catalysts for solar-driven CO2 hydrogenation reaction. The efficiency of CO2 hydrogenation can be enhanced through the combination of interband transition and active sites oxygen vacancies, coupled with exceptional photothermal conversion that rapidly elevates the catalyst surface temperature to 299 °C. Experimental results and characterization analyses reveal that the introduction of oxygen vacancies not only furnishes abundant adsorption and activation sites for CO2, but also extends the light absorption range of In2O3-x and improves the photothermal conversion efficiency. Black In2O3-x nanosheets with oxygen-rich defects exhibit remarkable solar-driven catalytic performance in the reverse water-gas shift (RWGS) reaction, achieving a CO generation rate as high as 69.8 mmol·h-1·m-2 with a selectivity approaching 100%. This study demonstrates that structural engineering of In2O3 nanosheets via a mild room temperature lithium reduction strategy significantly enhances catalytic activity, a methodology promising for broader applications.