Cu-doped molybdenum carbide encapsulated within two-dimensional nanosheets assembled hierarchical tubular nitrogen-doped carbon for enhanced hydrogen evolution

Abstract

Cu-doped molybdenum carbide encapsulated within nanosheets assembled hierarchical tubular nitrogen-doped carbon (Cu/Mo 2 C@HTNC) was fabricated through the coordination reaction between MoO 3 nanorod and dopamine followed by two-step consecutive pyrolysis, which exhibited excellent HER performance in alkaline condition due to the optimal strength of Mo−H bond from the increased electron density around Mo and catalytic active sites density after Cu doping. • Cu/Mo 2 C@HTNC was prepared by two-step consecutive pyrolysis of Mo-dopamine complex with the presence of Cu foil. • Doping Cu into Mo 2 C is found to increase the electron density around Mo and catalytic active sites density. • Cu/Mo 2 C@HTNC exhibits excellent a low overpotential of 113 mV at a current density of 10 mA cm −2 for HER. The development of low cost and high efficiency electrocatalyst for hydrogen evolution reaction (HER) is a key step in the realization of hydrogen production from electrolytic water. In this study, we report a feasible strategy to fabricate Cu-doped molybdenum carbide encapsulated within two-dimensional nanosheets assembled hierarchical tubular nitrogen-doped carbon (Cu/Mo 2 C@HTNC) through the coordination reaction between MoO 3 nanorod as template and dopamine in alkaline medium followed by two-step consecutive pyrolysis. The effective Cu doping into Mo 2 C crystal structure is found to increase the electron density around Mo and catalytic active sites density for optimizing the strength of Mo–H bond, thus facilitating the HER process. As expected, the optimal Cu/Mo 2 C@HTNC exhibits excellent HER performance with a low over-potential of 113 mV at a current density of 10 mA cm −2 and a small Tafel slope of 55 mV dec −1 as well as excellent stability in 1 M KOH.