In this work, we reported a facile and safe route for synthesis of Ni2P nanocatalysts by sol-gel method and demonstrated that the oxygen evolution reaction (OER) activity of Ni2P nanocatalysts can be dramatically enhanced by iron-doping and electrochemical activation. Compared with the fresh Fe-doped Ni2P nanocatalysts, a stable Fe-NiOOH layer was formed on the surface of Fe-doped Ni2P nanoparticles by electrochemical activation, thus promoting the charge transfer ability and surface electrochemically active sites generation for the electrochemical activated Fe-doped Ni2P nanocatalysts, ultimately accounting for the improvement of water oxidation activity, which was evidenced by cyclic voltammograms (CV), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectra (XPS) as well as high-resolution transmission electron microscopy (HR-TEM) measurements. For water oxidation reaction in 1 M KOH solution, the electrochemical activated Fe-doped Ni2P nanocatalysts can attain 10 mA/cm(2) at an overpotential of 292 mV with Tafel slope of 50 mV/dec, which was also much better than that of individual Ni2P, Fe2P nanocatalysts as well as commercial RuO2 electrocatalyst. Moreover, long-term stability performance by chronoamperometric and chronopotentiometric tests for the activated Fe-doped Ni2P nanocatalysts exhibited no obvious decline within 56 h. It was demonstrated that modulating the OER catalytic activity for metal phosphide by iron-doping and electrochemical activation may provide new opportunities and avenues to engineer high performance electrocatalysts for water splitting. (C) 2017 Elsevier Ltd. All rights reserved.