Tungsten nitride/carbide nanocomposite encapsulated in nitrogen-doped carbon shell as an effective and durable catalyst for hydrogen evolution reactionElectronic supplementary information (ESI) available. See DOI: 10.1039/c8nj04663h

Replacement of noble-metal platinum catalysts with low-cost, durability, and highly efficient electrocatalysts holds huge potential for hydrogen evolution reaction (HER). Transition-metal carbides and nitrides have attracted much attention on account of their specific noble-metal-like d-state density electron structure. Herein, we synthesized WN-W 2 C nanocomposites uniformly encapsulated in nitrogen-doped (4.21 atom%) carbon shell through in situ carbonized WO X /aniline hybrid nanoparticles. The catalysts displayed remarkable performance with a low overpotential of only 242 mV at 10 mA cm −2 and an excellent long-term durability performance i.e. , 5000 cycles owing to the protection of the carbon shell. The enhanced catalytic activities arose from the synergistic effect of tungsten nitride (WN) and tungsten carbide (W 2 C) nanocrystals and abundant nitrogen content. The current study might inspire the design of advanced and performance-oriented metal carbide and nitride-hybrid based electrocatalysts for wider applications in hydrogen evolution reaction. In situ carbonized WO X /aniline hybrid nanoparticles were prepared and used to obtain WN-W 2 C nanocomposites encapsulated in nitrogen-doped carbon shell, which demonstrated excellent HER performance.