Regulating the oxygen vacancies on the Ti3C2Tx/BiOCl Schottky heterojunction for highly efficient photoreduction of CO2 to CH4

The conversion of greenhouse gas CO 2 into usable high-value-added fuels through photocatalytic reactions is a promising green energy measure. However, the photocatalytic CO 2 reduction reaction faces challenges such as multi-electron transfer and slow mass transfer. Furthermore, most photocatalysts can only absorb ultraviolet light and have insufficient active sites, resulting in a low utilization rate of sunlight. Based on this, we designed a novel layered composite catalyst, where Ti 3 C 2 T x MXene serves as the supporting framework and BiOCl nanosheets are uniformly grown on its surface. Under simulated sunlight, the CH 4 yield is 30.07 μmol·g −1 ·h −1 , with a selectivity of 93.4 %, and it still maintains excellent stability after six photocatalytic cycle experiments. Research data indicates that with the intervention of reducing ethylene glycol, the oxygen vacancy content on Ti 3 C 2 T x /BiOCl is significantly increased. The formation of oxygen vacancies and Schottky heterojunctions not only enhances the charge separation efficiency at the interface but also selectively reduces CO 2 to CH 4 .