Nickel Phosphide Nanorod Arrays Vertically Grown on Ni Foam as High‐Efficiency Electrocatalyst for the Hydrogen Evolution Reaction

Abstract An electrocatalyst of nickel phosphide ( Ni 2 P ) nanorod arrays vertically grown on Ni foam composite ( NNFC ) was prepared successfully using NaH 2 PO 2 as phosphorus source by means of a facile method of in situ phosphorization of Ni foam. The as‐prepared NNFC exhibits excellent HER performance with an onset overpotential of 100 mV , a small Tafel slope of only 55 mV /dec, and a low overpotential involving 200 mV at a current density of 10 mA •cm −2 . Furthermore, the electrocatalyst was also demonstrated to possess high stability with a neglectable decrease in activity even after durability test for 25 h.