Mixed-solution synthesis of sea urchin-like NiSe nanofiber assemblies as economical Pt-free catalysts for electrochemical H2 production

Nickel (Ni)-based nanomaterials have been intensively explored as promising noble-metal-free hydrogen evolution reaction (HER) electrocatalysts. Here, we report that uniform sea urchin-like NiSe nanofiber assemblies can be prepared on a large scale by a ternary mixed solvent strategy. The new NiSe exhibits very high HER activity in 0.5 M H2SO4, comparable to the best performance of the well-studied MoS2 catalysts. The Tafel slope of similar to 64 mV per decade was observed for the sea urchin-like NiSe catalyst, suggesting that the Volmer-Heyrovsky HER mechanism presumably takes effect in the HER. Although the stability of such a NiSe nanofiber assembled nanostructure needs to be further improved, this study addresses the benefits and possibilities of using Ni-based chalcogenides to design high performance and low cost HER catalysts.