Synergistic Effect of Dual-Doped Carbon on MO_(2)C Nanocrystals Facilitates Alkaline Hydrogen Evolution

Molybdenum carbide(MO_(2)C)materials are promising electrocatalysts with potential applications in hydrogen evolution reaction(HER)due to low cost and Pt-like electronic structures.Nevertheless,their HER activity is usually hindered by the strong hydrogen binding energy.Moreover,the lack of water-cleaving site's makes it difficult for the catalysts to work in alkaline solutions.Here,we designed and synthesized a B and N dual-doped carbon layer that encapsulated on MO_(2)C nanocrystals(MO_(2)C@BNC)for accelerating HER under alkaline condition.The electronic interactions between the MO_(2)C nanocrystals and the multiple-doped carbon layer endow a near-zero H adsorption Gibbs free energy on the defective C atoms over the carbon shell.Meanwhile,the introduced B atoms afford optimal H_2O adsorption sites for the water-cleaving step.Accordingly,the dual-doped MO_(2)C catalyst with synergistic effect of non-metal sites delivers superior HER performances of a low overpotential(99 mV@10 mA cm^(-2))and a small Tafel slope(58.1 mV dec^(-1))in 1 M KOH solution.Furthermore,it presents a remarkable activity that outperforming the commercial 10%Pt/C catalyst at large current density,demonstrating its applicability in industrial water splitting.This study provides a reasonable design strategy towards noble-metal-free HER catalysts with high activity.