Ultrafine Ni-B nanoparticles for efficient hydrogen evolution reaction

The search for active, stable, and cost-effective electrocatalysts for hydrogen evolution reaction (HER) is desirable, but it remains a great challenge in the overall water splitting. Here, we report the synthesis of nickel boron nanoparticles supported on Vulcan carbon (Ni-B) via a simple, yet scalable, two-step chemical reduction–annealing strategy. The results of the electrochemical measurements suggest that the overpotentials of Ni-B-400 are 114 and 215 mV (in 1 mol L −1 KOH) at current densities of 10 and 40 mA cm −2 , respectively, indicating an exceedingly good electrocatalytic activity in the HER. More importantly, Ni-B maintains a current density of 7.6 mA cm −2 at an overpotential of 0.15 V for 20 h in the durability test. The excellent HER activity of Ni-B-400 is derived from the small particle size and the expanded lattice of Ni, which can optimize the hydrogen absorption energy and enhance the electrocatalytic properties. Ultrafine Ni-B nanoparticles can improve the reaction rate and efficiency of the electrocatalytic hydrogen evolution to produce high-purity hydrogen.