Preparation of mesoporous Ni2P nanobelts with high performance for electrocatalytic hydrogen evolution and supercapacitor

The development of bifunctional electrochemically-active materials for both hydrogen evolution reaction (HER) and supercapacitors enables the possibility to integrate energy storage and production into one single system. Here, we report a novel bifunctional mesoporous Ni₂P nanobelt-like architecture prepared via the hydrothermal synthesis of Ni(SO₄)_0.3(OH)_1.4 nanobelt precursor and subsequent low temperature phosphorization process under Ar atmosphere. Composed of numerous cross-linked Ni₂P nanoparticles, the as-obtained Ni₂P nanobelts exhibit a two dimensional leaf-like morphology, allowing remarkable enhancement of mesoporosity as well as active surface area. The HER electrocatalytic test in acid medium show a current density of 16 mA cm^?2 at an overpotential of 187 mV, Tafel slope of 62 mV dec^?1 and long-term durability. Investigation of this Ni₂P nanobelts as supercapacitor materials in 2M KOH electrolyte display a high specific capacity ranging from 1074 F g^?1 at 0.625 A g^?1 to 554 F g^?1 at 25 A g^?1, and notable cycling life with 86.7% retention after 3000 cycles at 10 A g^?1. With the simplicity of the synthetic routine and the outstanding performance as both HER catalysts and supercapacitors, the Ni₂P nanobelts provide promising potential for energy devices.