Highly Stable Ultrafine Boron‐Doped NiCo@Carbon Nanoparticles as a Robust Electrocatalyst for the Hydrogen Evolution Reaction

Abstract Developing robust, stable, low‐cost, and highly active environmentally friendly electrocatalysts for the hydrogen evolution reaction (HER) is necessary for realizing alternative clean energy sources. We prepared highly stable ultrafine NiCo@boron‐doped carbon (NiCo@BC) by using a simple reduction method. As an excellent and highly stable HER electrocatalyst, the as‐prepared NiCo@BC 500 °C nanoparticle catalyst displays a satisfying HER performance, delivering a low geometrical overpotential of 209 mV at 10 mA cm −2 current density, a small Tafel slope of 60 mV dec −1 , and an outstanding time‐dependent stability after 200 hours in an alkaline solution, which is one of the best reported B‐doped HER electrocatalysts. The outstanding catalytic activity arises from synergetic relationships between B‐doped carbon and NiCo, coexisting in the as‐prepared hybrid product with the crystalline nature of the hybrid NiCo@BC products bearing plentiful catalytically active sites and good electrical conductivity. The promising combination of robust stability, high catalytic performance, and a simplistic preparation approach provides a new‐type of electrocatalyst for clean energy technologies.