Cobalt‐Doping in Molybdenum‐Carbide Nanowires Toward Efficient Electrocatalytic Hydrogen Evolution

Abstract

Efficient hydrogen evolution reaction (HER) over noble‐metal‐free electrocatalysts provides one of the most promising pathways to face the energy crisis. Herein, facile cobalt‐doping based on Co‐modified MoO x –amine precursors is developed to optimize the electrochemical HER over Mo 2 C nanowires. The effective Co‐doping into Mo 2 C crystal structure increases the electron density around Fermi level, resulting in the reduced strength of Mo–H for facilitated HER kinetics. As expected, the Co‐Mo 2 C nanowires with an optimal Co/Mo ratio of 0.020 display a low overpotential ( η 10 = 140 and 118 mV for reaching a current density of –10 mA cm −2 ; η 100 = 200 and 195 mV for reaching a current density of –100 mA cm −2 ), a small Tafel slope (39 and 44 mV dec −1 ), and a low onset overpotential (40 and 25 mV) in 0.5 m H 2 SO 4 and 1.0 m KOH, respectively. This work highlights a feasible strategy to explore efficient electrocatalysts via engineering on composition and nanostructure.