MOF-derived Co/Co3O4/C hollow structural composite as an efficient electrocatalyst for hydrogen evolution reaction

Abstract

Stable, efficient catalysts are crucial for electrochemical water splitting. Metal–organic frameworks (MOFs) can be used to create electrocatalysts meeting these criteria; however, the lack of high-quality electrode materials for the hydrogen evolution reaction impedes their adoption. In this study, a hollow-structured Co/Co3O4/C composite was prepared using a Co-based MOF precursor through a two-step pyrolysis-oxidation process. This composite outperformed nonhollow Co/Co3O4/C structures as well as hollow Co/C and Co3O4/C composites as a catalyst for hydrogen production in alkaline media. It had a low overvoltage of 169 mV at a current density of 10 mA cm−2 and a moderate Tafel slope of 60.7 mV dec-1. Moreover, it exhibited remarkable durability with 2000 cycles and 12 h of testing. This can be attributed to the synergistic effect of Co, Co3O4, and the hollow morphological architecture, which promote the dissociation of HO–H bonds, recombination of hydrogen intermediates, and efficient electron transfer. The results of this study are highly promising for the fabrication of cost-effective electrode materials for water splitting. © 2022 Elsevier Ltd