Synthesis of W2N nanorods-graphene hybrid structure with enhanced oxygen reduction reaction performance

In this work, a novel hybrid structure of tungsten nitride nanorods upon graphene nano sheets was obtained by synthesizing WO. nanorods/graphene oxide (GO) nanosheets followed by hydrogenation and nitridization treatment. Electron microscopy and X-ray diffraction results indicated that the hybrid was composed of W2N nanorods and reduced graphene oxide nanosheets. Surface chemical characteristics of the hybrid were characterized by X-ray photoelectron spectroscopy (XPS) and its electrocatalytic activities were evaluated using a rotating disk electrode measurement system. Compared to the WO3 nanorods-GO hybrid, onset potential of the W2N nanorods-rGO hybrid for oxygen reduction reaction (ORR) was shifted from 0.6 V to 0.71 V, and the limiting current density increased by 1.4 times, exhibiting significantly enhanced electrocatalytic performance, which rendered the W2N-rGO hybrid as a potential non-precious-metal ORR catalyst in fuel cells and metal air battery applications. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.