Novel strongly coupled tungsten-carbon-nitrogen complex for efficient hydrogen evolution reaction

Alternatives to noble metal based electrocatalysts are vitally necessary to produce hydrogen from water at low overpotentials. Earlier research on tungsten based electrocatalyst has been mainly concentrated towards tungsten carbide (WC) and tungsten nitride (WN) as the potential electrocatalysts for hydrogen evolution reaction (HER), whereas tungsten carbide (W2C) has been least focused upon. Herein, we report a highly active novel strongly coupled tungsten-carbon-nitrogen complex (W2C-NC-WN complex) prepared by in situ carbonization method. This W2C-NC-WN complex exhibits a remarkable electrochemical performance for HER with a small onset potential of 33 mV vs. RHE and requires an overpotential (n) of 145 mV vs. RHE to render-10 mA cm(-2) current density. The Tafel analysis demonstrates a slope of 96 mV dec(-1) which is much better than WN (109.6 mV dec(-1)) and WC (142.4 mV dec(-1)). The strong coupling of W2C and WN within N-doped carbon (NC) framework brings about a significant enhancement in HER kinetics and faster electron transport due to the remarkable reduction in charge transfer resistance. The facile synthetic approach reported here, provides a powerful tool for the structurally controlled modification of the catalyst while simultaneously introducing active species. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.