Construction of 0D/2D Ni2P/Ni2P homophase Schottky junction by molten salt-assisted strategy for enhanced photocatalytic H2 evolution

Abstract

The pursuit of sustainable energy sources to replace fossil fuels has become an urgent matter. Hydrogen energy is the most suitable substitute, and the design of excellent and low-cost photocatalysts is particularly important. Herein, a zero-dimensional (0D) Ni2P nanoparticles (Ni2P NPs) fixed on two-dimensional (2D) Ni2P nanosheets (Ni2Ps) by a low-cost molten salt-induced partial phosphating strategy construction of 0D/2D Ni2P/Ni2Ps homophase Schottky junction for photocatalytic H2 evolution. Ni2Ps nanosheets provide large adsorption sites and reactive sites, which provides good adsorption conditions for Ni2P NPs. The aggregation of Ni2P NPs was weakened by the presence of Ni2Ps. A Schottky junction with a built-in electric field is formed between Ni2P NPs and Ni2Ps, which makes electrons migrate to Ni2P NPs from Ni2Ps, and Ni2P NPs in the reduction reaction as an electron accumulator. Interestingly, Ni2P/Ni2Ps heterojunction showed excellent photocatalytic activity (3106.6 μmol g−1 h−1), far more than Ni2P NPs (1221.4 μmol h−1 g−1) and Ni2Ps (1551.4 μmol h−1 g−1). This work not only shows a non-precious metal phosphide catalyst for photocatalytic H2 evolution, but also provides a new strategy to construction of Schottky junction for photocatalytic H2 evolution.