Solution-based Synthesis of NiSb Nanoparticles for Electrochemical Activity in Hydrogen Evolution Reaction

A cost-effective, facile solution-based hot-injection synthetic route has been developed to synthesize NiSb nanoparticles in oleylamine (OAm) using commercially available inexpensive precursor with reducing toxicity at a relatively low temperature of 160 oC. Especially, an organic reductant of borane-tert-butylamine complex is intentionally involved in the reaction system to promote a fast reduction of metallic Ni and Sb for the formation of the NiSb nanoparticles. Structural characterizations reveal that the NiSb nanoparticles are hexagonal phase with space group P6₃/mmc and they are composed of small granules with size about 10 nm that tend to form agglomerates with porous-like geometries. This is the first report on the generation of transition metal antimonide via solution-based strategy, and the asfabricated nanoparticles possess actively electrocatalytic hydrogen evolution reaction (HER) property in acidic electrolytes when the long-chain ligand of OAm adhered on the surface of the nanoparticles is exchanged by ligand-removal and exchange procedure. It is found that the NiSb nanoparticles as a new kind of non-noble-metal HER electrocatalysts only require overpotentials of 437 and 531 mV to achieve high current densities of 10 and 50 mA/cm² respectively, as well as exhibit low charge transfer resistance and excellent HER stability.