Bimetallic metal organic framework-derived Co₉S₈-MoS₂ nanohybrids as an efficient dual functional electrocatalyst towards the hydrogen and oxygen evolution reactions

Electrochemical water splitting is promising system for the efficient hydrogen production. Much effort has been devoted to developing cost-effective, catalytically active, and stable electrocatalysts for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). In this work, we synthesized Co9S8-MoS2 nanohybrid structures derived from CoMo-based bimetallic metal-organic frameworks via a one-pot hydrothermal route followed by sulfurization. Co9S8-MoS2 nanohybrids, composed of small Co9S8-MoS2 core-shell nanospheres covered by large Co9S8/MoS2 nanostructures, are efficient electrocatalysts for both the HER and OER owing to their porous bimetallic structures with large number of surface area and numerous catalytically active sites. The Co9S8-MoS2 nanohybrids show small overpotentials of 110 and 270 mV at 10 mA cm-2 in 1.0 M KOH for the HER and OER, respectively. Furthermore, even after 1000 cycles, the Co9S8-MoS2 nanohybrids exhibited good stability and small Tafel slopes of 59 and 66 mV dec(-1) for both the HER and OER, respectively, demonstrating their potential in practical applications for water splitting. (c) 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.