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

Developing metal nanoparticles (NPs)/carbon composite nanomaterials as electrocatalysts for hydrogen evolution reaction (HER) via a facile and low-cost strategy has attracted widely attention over the past decade. Herein, a series of nickel nanoparticles/carbon materials (Ni/C-m) composite electrocatalyst has been successfully synthesized via a simple molten salt pyrolysis method. Characterizations demonstrated that carbon materials can effectively prevent Ni nanoparticles 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, an appropriate carbon content can enhances electron transfer and promotes electrocatalytic HER activity. Ni/C-m exhibits better electrocatalytic HER activity than Ni sample which prepared without carbon materials precursor. The as-prepared Ni/C-0.8 composites electrocatalyst exhibits the lowest overpotential among all Ni/C-m samples (-109 mV at -10 mA cm-2 and -397 mV at -200 mA cm-2) and long-time stability. This research presents a new method for fabricating and designing a cost-effective, high-performance HER electrocatalyst for practical water splitting applications.