In-situ formation of Ni₂P on black phosphorus surface for efficient NIR photocatalytic singlet oxygen generation

Black phosphorus (BP) shows great potential applications in photoelectric conversion and photocatalysis, but its applications are limited by its disadvantages such as poor ambient stability and rapid carrier recombination under photoirradiation. In this work, it was surprisingly found that the in-situ generation of Ni2P onto the surface of BP leaded to a significant improvement in both ambient stability and photocatalytic singlet oxygen (1O2) generation under NIR irradiation. Because of the transfer of electrons from Ni to BP via Ni-P bonds, the Ni2P/BP showed better charge separation efficiency and ambient stability in NIR photoelectric conversion. Moreover, the Ni2P/BP was able to generate 1O2 for NIR photocatalysis through Russell Mechanism. Meanwhile, norfloxacin and E. coli could also be removed by Ni2P/BP under NIR irradiation, which further shows the ability to generate 1O2 for practical utilization. This work provides a novel insight into the passivation of BP by hetero-atoms doping and a new strategy for green NIR photocatalytic water remediation.