Herein, strongly coupled Mo2C and Ni nanoparticles with in-situ formed interfaces encapsulated by porous carbon nanofibers (Ni-Mo2C-CNF) have been rationally fabricated via pyrolyzing electrospinning polyvinyl alcohol fibers containing hydrothermally obtained NiMoO4 under Ar atmosphere and applied as high-performance and stable electrocatalyst for HER in alkaline electrolytes. Powered by NiMoO4 as homologous bimetallic precursor, the Ni-Mo2C-CNF possesses numerous in-situ formed Ni-Mo2C interfaces, which facilitates the synergistic effect between Ni and Mo2C, improving the conductivity and thus boosting the electrocatalytic performance towards HER. In the meantime, the porous carbon nanofibers with well encapsulated Ni-Mo2C active components stacks, constituting conductive network, which promotes the mass transport, electron transfer, active sites exposure and electrocatalytic stability. As a result, the Ni-Mo2C-CNF features prominently in HER, as it demands a low overpotential of 196 mV but is able to stably yield the current density of 10 mA cm(-2) with a small Tafel plot of 54.7 mV dec(-1). The method demonstrated in our work to synthesize bimetallic heterostructured materials will offer valuable inspiration to construct promising non-precious electrocatalysts for diverse vital renewable energy applications. (C) 2019 Elsevier Inc. All rights reserved.