▎ 摘　　要

The design and construction of highly efficient and stable Pt-free catalysts for the electrocatalytic hydrogen evolution reaction (HER) in alkaline media is extremely desirable. Herein, a novel hybrid of ruthenium (Ru) nanoparticles anchored on graphene hollow nanospheres (GHSs) is synthesized by a template-assisted strategy. The combination of ultrafine Ru nanoparticles and hollow spherical support endows the resultant Ru/GHSs an extraordinary catalytic performance with a low overpotential of 24.4 mV at a current density of 10 mA cm(-2), a small Tafel slope of 34.8 mV dec(-1), as well as long-term stability in 1.0 M KOH solution, which is, to our knowledge, superior to commercial 20% Pt-C catalyst and most of the state-of-the-art HER electrocatalysts reported. Remarkably, this work provides a new route for the development of other metal-based HER electrocatalysts for energy-related applications.