In situ surface engineering of ultrafine Ni2P nanoparticles on cadmium sulfide for robust hydrogen evolution

Exploring visible light-driven, low-cost semiconductor materials for water-splitting holds great promise to overcome the drawbacks of fossil fuel consumption and worsening worldwide pollution. Here we report the in situ growth of well-dispersed ultrafine Ni2P nanoparticles on CdS nanorods by a simple solvothermal method and a further surface phosphatization treatment for the first time. The as-synthesized Ni2P-CdS hybrid with optimal composition showed an average hydrogen evolution rate of 34.9 mmol h(-1) g(-1), which was about 23 times higher than that of pure CdS. The dramatically enhanced photocatalytic activity can be ascribed to the intimate interface between the well-dispersed ultrafine Ni2P cocatalysts and the CdS nanorods, which was favorable for the photogenerated electrons' transfer and separation which promoted the photocatalytic performance. Specifically, the introduction of well-dispersed ultrafine Ni2P cocatalysts was favorable for the trapping of photoexcited electrons and the subsequent reduction of protons to produce H-2 because of the shortened transfer path. Furthermore, the as-prepared hybrids exhibited good stability for hydrogen evolution under visible light irradiation.