The directional synthesis of transition metal phosphides was considered to be an effective strategy to solve the overdependence of noble metals on photocatalytic hydrogen evolution (PHE) reactions. Inspiringly, this work reported a facile method for constructing hollow Co₂P nanocages (Co₂P NCGs) that derived from ZIF-67 by calcining and phosphiding procedure in nitrogen atmosphere to act as non-noble metal cocatalysts. Followed with further coating thin-layered ZnIn₂S₄ (ZIS) on the surface of Co₂P NCGs through a hydrothermal reaction, the hierarchical robust Co₂P/ZnIn₂S₄ nanocages (Co₂P/ZIS NCGs) were then delicately fabricated as efficient photocatalysts for PHE reactions. The uniquely hollow structure of Co₂P NCGs largely diffused the photogenerated chargers that induced from ZIS and the closely interfacial contact significantly promoted the separation and transfer of electrons from ZIS to Co₂P according to density functional theory (DFT) calculation, synergistically resulting in an efficient hydrogen generation performance. PHE results showed that an efficient H₂ evolution rate of 7.93 mmol/g/h over 10% Co₂P/ZIS NCGs was achieved, about 10 times higher than that of pristine ZnIn₂S₄. More importantly, the hierarchically hollow Co₂P/ZIS NCGs exhibited ascendant PHE activity in comparison with that of 1% noble metal (Pt, Au, Ag) loaded ZnIn₂S₄ with superior sustainability, all indicating the efficient and stable photocatalysts of Co₂P/ZIS NCGs for PHE reactions.

https://doi.org/10.1016/j.jcis.2021.01.083