Ni nanoparticles decorated with carbon materials synthesized by a solid-state reaction for an efficient electrocatalytic hydrogen evolution reaction

Abstract

Developing metal nanoparticle (NP)/carbon composite nanomaterials as electrocatalysts for the hydrogen evolution reaction (HER) via a facile and low-cost strategy has attracted wide attention over the past decade. Herein, a series of nickel nanoparticle/carbon material (Ni/C-m) composite electrocatalysts have been successfully synthesized via a simple molten salt pyrolysis method. Characterization studies demonstrated that carbon materials can effectively prevent Ni nanoparticle aggregation and adjust the electron cloud density in Ni/C-m samples. During the preparation of Ni/C-m, the carbon content can be adjusted by varying the mass of sodium citrate, and an appropriate carbon content can enhance electron transfer and promote electrocatalytic HER activity. Ni/C-m exhibits better electrocatalytic HER activity than the Ni sample which is prepared without the carbon material precursor. The as-prepared Ni/C-0.8 composite electrocatalyst exhibits the lowest overpotentials among all Ni/C-m samples (−109 mV at −10 mA cm⁻² and −397 mV at −200 mA cm⁻²) and long-term stability. This research presents a new method for fabricating and designing a cost-effective, high-performance HER electrocatalyst for practical water splitting applications.