Exploring efficient, stable, and earth-abundant electrocatalysts for oxygen evolution reaction (OER) is of great significance for clean and renewable energy conversion technologies. In this work, in situ uniform Ni-doped tungsten carbide (Ni/WCX) nanoparticles (similar to 3 nm) on carbon nanofibers (Ni/WCX-CNFs) that were to function as efficient OER catalysts were developed. Both the composition and electronic state of tungsten carbide (WCX: W-WC-W2C) could be regulated through varied Ni coupling. Owing to the synergistic effect between Ni and WCX, the reaction kinetics were facilitated, resulting in improved OER activity with low overpotentials of eta(10) = 350 mV (modified glassy carbon electrode) and eta(10) = 335 mV (self-supporting electrode). This work opens a facile territory for the development of cost-effective and highly promising OER electrocatalysts for use in real life applications. (C) 2020 Elsevier Inc. All rights reserved.