Fabrication of effective electrocatalysts combining two pure phases including carbide and phosphide with a certain proportion by the clean and simple strategies still remain a challenge. Here we synthesized tungsten carbide/tungsten phosphide-coated N-doped carbon (W2C/WP@NC) by one-step pyrolysis process without participation of PH3. In this synthesis process phosphotungstic acid, a heteropolyacid provided P and W atoms while 2,6-diaminopyridine, a heterocyclic compound with strong alkalinity acted as C and N source. 2,6-diaminopyridine was carefully chosen because it made a contribution to the complete decomposition of phosphotungstic acid where WO42- and PO43- groups were formed which both were essential to formation of WP phases. An overpotential of 83 mV which was required to achieve a current density of 10 mA cm(-2) in 0.5 M H2SO4 exhibited the high electrocatalytic activity of W2C/ WP@NC catalyst in hydrogen evolution reaction (HER). The weight ratio of W2C to WP was calculated by Rietveld refinement and near edge X-ray absorption fine structure (XANES). W L(3)3-edge XANES spectra of different samples confirmed that little amount of WP could tune the electron state on W species. The enhanced HER performance was attributed to the favorable electron distribution on W species in W2C/ WP@NC which approached to the balance between H-atom adsorption and desorption. (C) 2018 Elsevier Ltd. All rights reserved.