Surface engineering induced hierarchical porous Ni12P5-Ni2P polymorphs catalyst for efficient wide pH hydrogen production

Exploring nickel phosphides electrocatalysts with both massive active sites and superior intrinsic activity for efficient and robust hydrogen evolution reaction (HER) is highly desirable, yet challenging. Here we constructed a novel Ni12P5-Ni2P polymorphs catalyst (Ni-P/Ni/NF) through a successive hydrothermal treatment and annealing process on deliberately coarsened nickel foam (Ni/NF) support. Our experimental and theoretical studies demonstrate the application of Ni/NF is key to rendering a unique hierarchical porous architecture with Ni12P5-Ni2P heterostructures, which not only increases the number of active sites but also enhances the intrinsic activity of the catalyst. Such a unique structure endows Ni-P/Ni/NF with low overpotentials of 129, 83, and 112 mV (at current density of 10 mA cm−2) for HER in alkaline, acidic and neutral media, respectively, which surpasses many of reported state-of-the-art nonprecious HER catalysts. This work presents a valuable route for designing and fabricating inexpensive and high-performance catalysts for electrocatalysis and beyond.