Anchoring MnCo2O4 Nanorods from Bimetal-Organic Framework on rGO for High-Performance Oxygen Evolution and Reduction Reaction.

Abstract

Oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are important reactions of energy storage and conversion devices. Therefore, it is highly desirable to design efficient and dual electrocatalysts for replacing the traditional noble-metal-based catalysts. Herein, we have developed a high-efficiency and low-cost MnCo2O4-rGO nanocomposite derived from bimetal-organic frameworks. For OER, MnCo2O4-rGO showed an onset potential of 1.56 V (vs reversible hydrogen electrode (RHE)) and a current density of 14.16 mA/cm2 at 1.83 V, being better than both pure MnCo2O4 and Pt/C. For ORR, MnCo2O4-rGO exhibited a half-wave potential (E1/2) of 0.77 V (vs RHE), a current density of 3.33 mA/cm2 at 0.36 V, a high electron transfer number n (3.80), and long-term stability, being close to the performance of Pt/C. The high activity of MnCo2O4-rGO was attributed to the synergistic effect among rGO, manganese, and cobalt oxide. As a result, the resultant MnCo2O4-rGO has a great potential to be applied as a high-efficiency ORR and OER electrocatalyst.