Nickel Boride Cocatalyst Boosting Efficient Photocatalytic Hydrogen Evolution Reaction

Abstract

Noble metals have been extensively used as catalyst promoters to driven highly efficient photocatalytic hydrogen evolution reaction (HER). However, noble-metal-based promoters are limited by their expensive costs and scarcities. Recently, massive efforts have been focused on metal phosphides, metal sulfides, and metal carbides as cocatalysts to achieve high HER performance. Currently, metal borides were reported as promoters for hydrogen evolution. Here, we demonstrate amorphous nickel boride (NiB) with a suitable band gap prepared by the chemical reduction of nickel nitrate hexahydrate using sodium borohydride as a cocatalyst over graphite carbon nitride (C3N4), thus achieving higher hydrogen evolution performance than C3N4. With the B(δ−)–Ni(δ+)–N(δ−) bonds between NiB and C3N4, the as-prepared C3N4/NiB7.5 shows a dramatically enhanced photocatalytic hydrogen generation rate (464.4 μmol h–1 g–1), and reaches a quantum efficiency of 10.92% with 365 nm light irradiation.