Co/Mo2C composites for efficient hydrogen and oxygen evolution reaction

Non-precious transition metal electrocatalysts with high catalytic performance and low cost enable the scalable and sustainable production of hydrogen energy through water splitting. In this work, based on the polymerization of CoMoO4 nanorods and pyrrole monomer, a heterointerface of carbon-wrapped and Co/Mo2C composites are obtained by thermal pyrolysis method. Co/Mo2C composites show considerable performance for both hydrogen and oxygen evolution in alkaline media. In alkaline media, Co/Mo2C composites show a small overpotential, low Tafel slope, and excellent stability for water splitting. Co/Mo2C exhibits a small overpotential of 157 mV for hydrogen evolution reaction and 366 mV for oxygen evolution reaction at current density of 10 mA cm(-2), as well as a low Tafel slope of 109.2 mV dec(-1) and 59.1 mV dec(-1) for hydrogen evolution reaction and oxygen evolution reaction, respectively. Co/Mo2C composites also exhibit an excellent stability, retaining 94% and 93% of initial current value for hydrogen evolution reaction and oxygen evolution reaction after 45,000 s, respectively. Overall water splitting via two-electrode water indicates Co/Mo2C can hold 91% of its initial current after 40,000 s in 1 M KOH. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.