Black phosphorus coupled bismuth chloride oxide nanocomposites for efficient photocatalytic CO2 reduction†
Abstract
Developing and utilizing solar to chemical energy conversion is a promising and efficient approach to green carbon-neutral energy systems. Herein, we report a facile solvothermal reaction strategy using black phosphorus (BP) nanosheets coupled with bismuth oxychloride (BiOCl) to prepare uniform BP/BiOCl composite nanocatalysts with enhanced wide-spectrum light absorption and electron-rich P modulated surface acid–base properties. BP/BiOCl possesses a typical layered structure showing the features of excellent separation of electron–hole pairs and electron transfer for efficient photocatalytic CO2 reduction to CO. Notably, the engineered BP/BiOCl nanocomposite with substantial BP–BiOCl synergy exhibits a superior CO production rate of up to 260 μmol g−1 h−1, which is 130 and 13 times higher than those of BP and BiOCl counterparts, respectively. Meanwhile, the BP/BiOCl material shows excellent photostability for CO2 transformation under visible light irradiation. The 13C isotope labeling experiment confirms that the carbon source of C-containing products is derived from the CO2 substrate during the photocatalysis process. The S-scheme mechanism involving excited electron transfer and direct participation in chemical activation of inert CO2 molecules, generation of key intermediate CO*, and final gas products for photocatalytic CO2 reduction over the BP/BiOCl composite is thus proposed.