Fabrication of CNTs encapsulated nickel-nickel phosphide nanoparticles on graphene for remarkable hydrogen evolution reaction performance

Abstract

Efficient hydrogen evolution reaction (HER) has become an increasingly eye-catching strategy for renewable clean energy production. To promote the catalytic performance and reduce the H2 generation costs, transition metal catalysts have been widely studied. In this work, we employed reduced graphene oxide (rGO) as a platform to grow carbon nanotubes (CNTs) confined Ni–Ni12P5 nanoparticles (Ni-Ni12P5@CNTs/rGO). The obtained catalyst was carefully characterized and found that the metallic Ni is essential to the formation of CNTs and promotion of HER performance. The Ni-Ni12P5@CNTs/rGO composite with unique structure showed an excellent HER performance in an acidic solution with a Tafel slope of 55.43mV dec−1 and an exchange current density of 5.62×10−3mAcm−2, which is much higher than the metallic Ni free catalyst. Further experiments found that the boosted HER performance originates from the synergic effect of metallic Ni, Ni-Ni12P5, and CNTs. Moreover, owing to the confining effect of the CNTs, the Ni-Ni12P5@CNTs/rGO showed outstanding stability during the 10h stability test.