Ni@Ni3C Nanochain-SWCNT Composite with Comparable Electrocatalysis of Benchmark Pt/C for Hydrogen Evolution Reaction

Developing robust and low-cost electrocatalysts for efficient hydrogen evolution reaction (HER) through facile methods is of great significance to the energy and environment sustainability. Herein, a simple one-pot solvothermal method has been developed to synthesize a hybrid material of nickel@nickel carbide (Ni@Ni3C) nanochain embedded in a network of single-walled carbon nanotubes (SWCNTs). The electrochemical experiments indicate that the composite of Ni@Ni3C-SWCNTs has the HER electrocatalytic performance comparable to that of Pt/C in an acidic medium (0.5 M H2SO4). The overpotential to reach a current density of 10 mA cm−2 in 0.5 M H2SO4 is only −74 mV with a Tafel slope of 46.9 mV dec−1. Compared to Ni@Ni3C in the absence of SWCNTs, the enhanced HER performance of Ni@Ni3C-SWCNTs can be attributed to the increased intrinsic activity, improved electronic conductivity, and the electron coupling effect between Ni@Ni3C and SWCNTs. The Ni@Ni3C-SWCNTs composites also show high stability at the overpotential of −0.2 V for 24 h. This work provides guidance for the synthesis of high-performance non-precious metal electrocatalysts for HER.