Efficient hydrogen evolution enabled by in-situ synthesis of biphasic Mo2C/Mo16N7 nitrogen-doped carbon nanorods as catalysts

Molybdenum carbide (Mo 2 C) has gained significant recognition as a cutting-edge, non-precious transition metal catalysts for efficiently driving the hydrogen evolution reaction (HER). However, the desorption of Mo-H bonds on the pristine Mo 2 C surface are difficult, resulting in a slow Heyrovsky/Tafel step. Herein, biphasic Mo 2 C/Mo 16 N 7 nitrogen doped carbon nanorods (Mo 2 C/Mo 16 N 7 @NRs) is synthesized as the high-performance HER electrocatalyst by using a one-step in-situ pyrolysis growth method. It is found that a suitable pyrolysis temperature can simultaneously tune the morphology of the catalyst and form abundant heterointerface. Benefit from abundant porous nanostructure and more electron-rich Mo active sites at the Mo 2 C-Mo 16 N 7 interfaces, the optimized Mo 2 C/Mo 16 N 7 @NRs demonstrates exceptional catalytic activity. It achieves low overpotentials ( η 10 ) of 63.62 and 117.43 mV at 10 mA cm −2 , accompanied by Tafel scopes of 49.73 and 64.44 mV dec −1 in both alkaline and acidic electrolytes. Also, Mo 2 C/Mo 16 N 7 @NRs shows long-lasting stability for 24 h in the different electrolytes. The experimental and theoretical findings explain the synergistic effects of unique morphology control and interface engineering on electrocatalyst activity. The one-step in-situ pyrolysis growth method is expected to produce non-precious metal catalysts with distinct morphology and heterointerfaces.