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

Abstract

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.

Green synthesis of fusiform-shaped Fe-PANI as a phenomenal dual electrocatalyst for overall water splitting and assessment of its sustainability standards

“…The HR-TEM image of Fe-PANI reveals that it is fusiform (spindle) with semi-transparent spotty features. 26 Small and uniformly distributed iron particles can be clearly seen in the PANI matrix (Fig. 6).…”

Growth of Flower-like MnO2 on Porous ZIF-67 for Achieving Enhanced Supercapacitive Properties

“…The binding energy and spin energy separation (11.7 eV) are in agreement with the previously reported values of δ-MnO 2 . , With a nanoflower-like surface morphology, the δ-MnO 2 in ST@ZIF-67/MnO 2 can provide a large number of active sites for highly reversible chemical reactions during the charge–discharge cycling process. As for the Co 2p spectrum shown in Figure S5, the two pronounced peaks located at 780.4 and 796.1 eV correspond to Co 2p 3/2 and Co 2p 1/2 , respectively …”

“…As for the Co 2p spectrum shown in Figure S5, the two pronounced peaks located at 780.4 and 796.1 eV correspond to Co 2p 3/2 and Co 2p 1/2 , respectively. 46 Electrochemical properties of the as-prepared electrode materials were assessed by a three-electrode system using 1 M Na 2 SO 4 as the electrolyte. In the typical CV curves shown in Figure 6a (at scan rate of 10 mV s −1 ), no decent redox peaks are observed for the MnO 2 -containing samples (ST@ZIF-67/ MnO 2 and ZIF-67/MnO 2 ), which can be attributed to the rapid reversible surface redox reactions of the electrode materials and implies good EDLC capacitive behavior.…”

Advances and Outlook of Metal–Organic Frameworks as High-Performance Electrocatalysts for Hydrogen Evolution Reaction: A Minireview

“…Electrochemical water-splitting is a prominent approach among renewable alternatives for hydrogen production. − It has a minimal environmental impact as it uses water as the main raw material. , Oxygen is also harmless and can even increase profitability by providing new uses. , The splitting of water involves the occurrence of two distinct half-reactions, namely the oxygen evolution reaction and the hydrogen evolution reaction, yet the kinetics of both reactions are relatively slow. , A catalyst is crucial to break the tight connection between oxygen and hydrogen within water molecules, allowing the process to proceed efficiently. , Noble metals serve as the basis for commonly used catalysts, including iridium, ruthenium, and platinum, − which have the drawback of high cost and limited availability, which limits their practical application. Additionally, their durability is also questionable, further hindering their widespread use …”

“…13,14 Oxygen is also harmless and can even increase profitability by providing new uses. 11,15 The splitting of water involves the occurrence of two distinct half-reactions, namely the oxygen evolution reaction 16 and the hydrogen evolution reaction, yet the kinetics of both reactions are relatively slow. 11,17 A catalyst is crucial to break the tight connection between oxygen and hydrogen within water molecules, allowing the process to proceed efficiently.…”