Charge compensation co-doping enhances the photocatalytic activity of black phosphorus

Abstract

Visible light (VL) photocatalysts have received widespread attention because they can improve the utilization of sunlight and have application prospects in degrading organic pollutants. In this work, using first principles study, we systematically investigated the photocatalytic performance of metal (Ge and Sn) and nonmetal (O, S and Se) charge compensated co-doped black phosphorus (BP). The results indicate that the incorporation of the Ge and Se atom in the BP lattice will be easier in the presence of O (or S or Se) dopant. Charge compensated co-doping can eliminate the flat impurity levels (ILs) in the band gap of Ge and Sn single doped BP. More importantly, Ge-O and Sn-O co-doping can suppress the recombination rate of photogenerated carriers, increase the number of catalytic active sites, enhance the redox potential of photogenerated carriers and improve the absorption efficiency of VL. This work has guiding significance for promoting the applications of BP-based VL photocatalyst.