A superior ternary Z-scheme photocatalyst of Bi/Black Phosphorus nanosheets/P-doped BiOCl containing interfacial P-P bond and metallic mediator for HO production and RhB degradation.

Photocatalytic performance is significantly influenced by the efficiency of photogenerated electron-hole pairs separation and transfer. In this paper, rational designed Z-scheme Bi/Black Phosphorus Nanosheets/P-doped BiOCl (Bi/BPNs/P-BiOCl) nanoflower photocatalyst was synthesized by a facile in-situ reduction process. The interfacial P-P bond between Black phosphorus nanosheets (BPNs) and P-doped BiOCl (P-BiOCl) was investigated by the XPS spectrum. The Bi/BPNs/P-BiOCl photocatalysts exhibited enhanced photocatalytic performance for HO production and RhB degradation. The optimally modified photocatalyst (Bi/BPNs/P-BiOCl-20) showed an excellent photocatalytic HO generation rate of 4.92 mM/h and RhB degradation rate of 0.1169 min under simulated sunlight irradiation, which was 1.79 times and 1.25 times greater than the P-P bond free Bi/BPNs/BiOCl-20. The mechanism was investigated through charge transfer route, radical capture experiments, and band gap structure analysis, indicating that the formation of Z-scheme heterojunctions and interfacial P-P bond not only enhances the redox potential of the photocatalyst but also facilitates the separation and migration of photogenerated electrons-holes. This work might provide a promising strategy for constructing Z-scheme 2D composite photocatalysts combining interfacial heterojunction and elemental doping engineering for efficient photocatalytic HO production and organic dye pollutant degradation.