Hybridization of Bimetallic Molybdenum‐Tungsten Carbide with Nitrogen‐Doped Carbon: A Rational Design of Super Active Porous Composite Nanowires with Tailored Electronic Structure for Boosting Hydrogen Evolution Catalysis

Abstract

AbstractAn ecofriendly and robust strategy is developed to construct a self‐supported monolithic electrode composed of N‐doped carbon hybridized with bimetallic molybdenum‐tungsten carbide (MoxW2−xC) to form composite nanowires for hydrogen evolution reaction (HER). The hybridization of MoxW2−xC with N‐doped carbon enables effective regulation of the electrocatalytic performance of the composite nanowires, endowing abundant accessible active sites derived from N‐doping and MoxW2−xC incorporation, outstanding conductivity resulting from the N‐doped carbon matrix, and appropriate positioning of the d‐band center with a thermodynamically favorable hydrogen adsorption free energy (ΔGH*) for efficient hydrogen evolution catalysis, which forms a binder‐free 3D self‐supported monolithic electrode with accessible nanopores, desirable chemical compositions and stable composite structure. By modulating the Mo/W ratio, the optimal Mo1.33W0.67C @ NC nanowires on carbon cloth achieve a low overpotential (at a geometric current density of 10 mA cm−2) of 115 and 108 mV and a small Tafel slope of 58.5 and 55.4 mV dec−1 in acidic and alkaline environments, respectively, which can maintain 40 h of stable performance, outperforming most of the reported metal‐carbide‐based HER electrocatalysts.