Design of hydrangea-type Co/Mo bimetal MOFs and MOF-derived Co/Mo2C embedded carbon composites for highly efficient oxygen evolution reaction

Abstract

Transition metal organic framework (MOF)-derived catalysts are considered as promising electrocatalysts for the oxygen evolution reactions (OER) owing to their large surface area and abundant catalytic sites. However, to overcome the remaining limitations of their catalytic performance, it is imperative to develop catalysts with more efficient structure and sufficient intrinsic activity. Herein, we report a creative strategy for preparing efficient OER catalysts based on the Co/Mo MOFs with a two-dimensional (2D) hydrangea-type structure by employing molecular binders. In addition, these MOFs were successfully converted into hydrangea-type 2D Co/Mo2C heterostructure nanoparticles embedded in a N-doped carbon composite (H-2D Co/Mo2C@NC). Remarkably, H-2D Co/Mo2C@NC exhibited excellent OER performance with a low overpotential of 256 mV@η10 and a low Tafel slope of 48 mVdec−1. This can be attributed to the large accessible surface area of the nanoparticles owing to their hydrangea-type structure with open active sites and the modulation of the electronic structure of Co by Mo2C. This strategy will provide useful insights into the design of MOF-derived bimetal catalyst and heterojunction catalysts.