Construction of a self-supporting Ni2P–WO3 heterostructure for highly efficient hydrogen evolution under both caustic and acidic conditions

Abstract

The development of low-cost and highly efficient hydrogen evolution reaction (HER) catalysts remains a significant challenge for the advancement of sustainable energy conversion systems. Herein, we have reported the successful preparation of an amorphous WO₃ adjusted nickel phosphide (Ni₂P–WO₃/CC)-based HER catalyst through a facile and scalable method. The optimized Ni₂P–WO₃/CC catalyst has excellent HER performance under both 1.0 M KOH (105 mV@10 mA cm⁻²) and 0.5 M H₂SO₄ (107 mV@10 mA cm⁻²) conditions, respectively. Moreover, in a simulated industrial two-electrode alkaline system, the developed catalyst can provide current densities of 500 and 1000 mA cm⁻² at cell voltages of 1.8 and 1.9 V, respectively. Such excellent HER activity is significantly higher than those of noble-metal-based catalysts. These results indicate that WO₃ has an important role in inducing the transformation of the nickel phosphide crystal structure. The remarkable catalytic performance is due to the synergy between WO₃ and Ni₂P, as well as the unique porous structure, which can enhance electron transfer, supply more active sites, and accelerate electrolyte transfer and gas emission. This study facilitates the development of new design strategies for HER catalysts and the promotion of their industrial applications.