High purity H-2 formed by electrochemical water splitting is profound potential green energy. Exploiting advanced electrocatalysts for hydrogen evolution reaction (HER) in both acidic and base environment is of critical significance. Herein, we report a novel hybrid comprising stacked cobalt tungsten carbides nanocrystals on N-doping carbon matrix (Co6W6C-N@CNFs) as a superb HER catalyst over the entire pH range via facile electrospinning and CVD method. On account of its ultrathin size and the strong synergetic interaction between bimetals, coupled with the superior conductivity of N-doping CNFs, Co6W6C-N@CNFs presents superior catalytic properties, with low overpotentials of 86 and 116 mV at eta(10) and small Tafel slopes of 85 and 101-mV dec(-1) in acidic and alkali, respectively, as well as outstanding long-term stability, rivalling its potential to be used intensively in water electrolysis technologies. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.