In-situ synthesis of ternary metal phosphides NixCo1−xP decorated Zn0.5Cd0.5S nanorods with significantly enhanced photocatalytic hydrogen production activity

Abstract

Novel ternary metal phosphides NixCo1−xP decorated Zn0.5Cd0.5S nanorod photocatalysts have been synthesized via a facile in-situ phosphating method for the first time to promote the H2 production performance. The preparing procedure allows the NixCo1−xP nanoparticles (NPs) to disperse on the surface of Zn0.5Cd0.5S nanorods uniformly and produce intimate contact interfaces. The photocatalytic H2 production activity of Zn0.5Cd0.5S nanorods is remarkably improved by introducing noble metal free NixCo1−xP promotors. Especially, the nanohybrid of 4 mol% Ni0.1Co0.9P-Zn0.5Cd0.5S shows the highest photocatalytic performance with a H2 evolution rate of 976 µmol·h−1, which is 11.7 folds higher than obtained with pure Zn0.5Cd0.5S. The apparent quantum yield (AQY) of the hybrid photocatalyst is estimated to be 19.7% at monochromatic 420 nm. The catalytic activity is still stable after 16 h cycling experiments. Moreover, based on the calculation of density function theory (DFT), the rational mechanism of photocatalytic has been proposed and is well consistent with the experimental results. In addition, the formed coordination bond between Zn0.5Cd0.5S and Ni0.1Co0.9P on their surface plays an important role in charge separation and transfer. Our study not only demonstrates a facile and scalable strategy to synthesize highly efficient photocatalysts, but also provides a new viewpoint of the rational design and synthesis of advanced photocatalysts by harnessing the strong synergistic effects through simultaneously tuning the ratio of metal in metal phosphides.