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
Huan Li, Minghao Hu, Luyao Zhang, Lili Huo, Peng Jing, Baocang Liu, Rui Gao, Jun Zhang, Bin Liu
Abstract
Abstract An ecofriendly and robust strategy is developed to construct a self‐supported monolithic electrode composed of N‐doped carbon hybridized with bimetallic molybdenum‐tungsten carbide (Mo x W 2− x C) to form composite nanowires for hydrogen evolution reaction (HER). The hybridization of Mo x W 2− x C 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 Mo x W 2− x C 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 (Δ G H* ) 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 Mo 1.33 W 0.67 C @ 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.