Molybdenum (Mo) based materials including its phosphides, carbides, nitrides, oxides, dichalcogenides and metallic alloys have received particular interest in recent years for sustainable hydrogen evolution reaction (HER) electrocatalysis. In this study, a novel Mo2C/MoP hybrid nanoparticle embedded N, P co-doped carbon nanofibers on carbon fiber paper (Mo2C-MoP NPC/CFP-800) is successfully prepared as a highly efficient hierarchical HER electrocatalyst. Benefitting from its structural advantages and compositional merits, this Mo2C-MoP NPC/CFP-800 electrocatalyst displays remarkable catalytic activity as well as excellent durability for HER. Only 85 and 146 mV overpotential is required to drive a HER current density of 10 mA cm(-2) in acidic and alkaline solution, respectively. Remarkably, this electrocatalyst is also able to fulfill efficient HER even in seawater. Further, this work reveals that the Mo2C/MoP hybrid nanoparticle is superior to MoP nanoparticle under present system in HER electrocatalysis, which may offer valuable clues on further design and synthesis of HER electrocatalysts. (c) 2018 Elsevier Ltd. All rights reserved.