Enhanced photocatalytic performance of black phosphorene by isoelectronic co-dopants†
Black phosphorene has been proposed as a high-efficiency metal-free two-dimensional photocatalyst for hydrogen production by visible light-driven water splitting. In this work, based on the screening of materials by density functional theory calculations, the potentials of group IV and group VI isoelectronic co-doped black phosphorenes (BPs) as candidate photocatalysts were comprehensively evaluated. According to the essential criteria of stability, electronic structure features, as well as visible light photocatalytic hydrogen production performance, we identified Si–S, Si–Se, Ge–S and Ge–Se co-doped BPs as promising catalysts. We highlighted that the isoelectronic co-doping process is geometrically and thermodynamically favorable. Interestingly, the isoelectronic co-dopants did not affect the direct and clean band gap nature of pure BP, and they also enhanced the photocatalytic hydrogen production properties, retaining a strong anisotropic feature. We believe that our findings will shed light on the modulation and development of BP based metal-free two-dimensional photocatalysts.