Cobalt Formate, a Functional MOF: Electrocatalytic Water Oxidation

Abstract

Cobalt formate dihydrate, Co(HCOO)[Formula: see text]H2O (Co-MOF), a known crystalline substance, is a three-dimensional coordination polymer. The compound crystallizes in a monoclinic space group [Formula: see text]. In this work, we are reporting a unique synthesis method to prepare this MOF without using any formate salt or formic acid. The source of formate in compound Co-MOF is dimethylformamide (DMF) solvent used in the relevant synthesis. This metal–organic framework (MOF) containing compound, which can be described as a functional MOF, has recently been exploited for hydrogen isotope separation. This functional material has never been used as an electrocatalyst. In this work, we have demonstrated that this water insoluble compound Co-MOF can be used as heterogeneous electrocatalyst for oxygen evolution reaction (OER) by water oxidation at neutral pH. An overpotential of 275.5[Formula: see text]mV versus RHE was required to attain a current density of 1[Formula: see text]mAcm[Formula: see text]. The relevant Faradic efficiency (89.93%) and the turn over frequency (TOF) of 0.277[Formula: see text]s[Formula: see text] make the material an efficient electrocatalyst for water oxidation to molecular oxygen at neutral pH.