In this work, carbon microfibers modified with Mo2C and metallic Ni (Mo2C-Ni-CMF0.2) was successfully synthesized by one-step strategy and demonstrated that it is efficient and stable low-cost electrocatalyst for hydrogen evolution reaction (HER) in acidic conditions. The as-obtained Mo2C-Ni-CMF0.2 shows excellent HER activity with a low overpotential (131 mV) to reach current density of 10 mA cm(-2), a small Tafel plot (34.1 mV dec(-1)) and remarkable stability. The carbonized cotton fibers has a pore structure and a large specific surface area, which is beneficial for improving electrocatalytic activity. Moreover, cotton fibers also provide a carbon source for the formation of Mo2C during carbonization. The catalyst owes better activity to the electrion transmission facilitated by the synergy between Mo2C and Ni, and the adsorption of H+ based on pore structure. (C) 2019 Elsevier Inc. All rights reserved.