Anchoring ultra-small Mo 2 C nanocrystals on honeycomb-structured N-doped carbon spheres for efficient hydrogen evolution.

Molybdenum carbide (Mo 2 C) has attracted considerable research interest as one of the most efficient non-noble electrocatalysts for the hydrogen evolution reaction (HER). Supporting nanosized Mo 2 C on a conductive carbon matrix with high porosity and large surface area represents an efficient strategy to enhance its HER performance. Herein, we constructed a Mo 2 C based HER catalyst consisting of ultra-small Mo 2 C nanocrystals anchored on honeycomb-structured N-doped carbon spheres (Mo 2 C-HNCS). The as-prepared Mo 2 C-HNCS manifests a high HER catalytic activity in alkaline media with an overpotential of 128 mV at 10 mA cm -2 , a Tafel slope of 60 mV decade -1 , and good stability.