Z‐scheme Heterojunction Photocatalyst Based on Lanthanum Single‐Atom Anchored on Black Phosphorus for Regulating Surface Active Sites, therefore Enhancing Photocatalytic CO2 Reduction with ≈100% CO Selectivity

The advent of Z‐scheme heterojunction makes it possible to improve the CO2 photoreduction efficiency of photocatalyst significantly. However, the reasonable construction of heterojunction and study of the photocatalytic mechanism remains a major challenge. Here, the Z‐scheme heterojunction photocatalyst (BP:La/InVO4:La) based on La single atom anchored on black phosphorus for photocatalytic CO2 reduction with ≈100% CO selectivity is successfully constructed. The CO generation rate of BP:La/5‐InVO4:La is ≈7.9 and 4.9 times higher than black phosphorus and InVO4, respectively. The results of X‐ray photoelectron spectroscopy, photoluminescence, and density functional theory indicate that the BP:La/InVO4:La belongs to the Z‐scheme heterojunction, and the La single atom plays multiple roles such as regulating surface active sites, promoting CO2 absorption, and increasing O defects, which can further contribute to the improvement of photocatalytic performance. The enhanced selectivity of the Z‐scheme heterojunction is further demonstrated by calculating the rate‐determining steps and selectivity‐determining steps. The results are expected to provide unique ideas for the rational design of rare earth composite photocatalyst.