A Facile Synthesis of a Fusiform-Shaped Three-Dimensional Co/ Mn@CNDs-MOF Nanocomposite as an Efficient Electrocatalyst for Oxygen Evolution Reaction in Alkaline Medium

A facile synthesis of a bimetallic metal-organic framework (MOF) codoped with carbon nanodots (CNDs) (Co/Mn@CNDs-MOF) via solvothermal treatment is reported. In this study, we prepared a composite material with nanofusiform-like structures as an efficient earth-abundant oxygen evolution reaction (OER) electrocatalyst, its morphology was confirmed by high-resolution transmission electron microscopy, and the calculated average particle size of the Co/Mn@CNDs-MOF was 10.5 nm. Electrochemical methods were performed to examine the catalytic OER of the Co/Mn@CNDs-MOF electrode. The MOF composite revealed high current densities of 50 and 100 mA/cm2 at 280 and 320 mV overpotentials, respectively, with a low Tafel slope of 140 mV dec-1 in a 1 M KOH aqueous electrolyte toward OER. Here, the incorporation of CNDs into a bimetallic MOF increases the surface area, active sites, and moreover the electrocatalytic activity of the composite, revealing almost equal properties when compared to a commercial catalyst, ruthenium oxide (RuO2). This research provides an outstanding avenue to realize multifunctional electrocatalysts.