Hierarchically Porous Co3C/Co-N-C/G Modified Graphitic Carbon: A Trifunctional Corrosion-Resistant Electrode for Oxygen Reduction, Hydrogen Evolution and Oxygen Evolution Reactions

Abstract

Developing highly active and robust electrode catalysts for oxygen reduction reaction, hydrogen evolution reaction, and oxygen evolution reaction is critical for realizing efficient energy conversion and storage devices. In this work, we synthesize a hierarchically porous electrocatalyst (Co3C/Co-N-C/G) via a two-step process including hydrothermal and pyrolysis procedures. During the hydrothermal process, an acid-base reaction is induced to create abundant defects in the materials. Physicochemical characterizations of the catalyst suggest that the starting material of pyridine-3,4-dicarbonitrile leads to graphitic carbon structure, and stable Co-N-C and Co3C active centers are generated. Due to the synergistic effects among the components, the catalyst exhibits excellent catalytic activity for oxygen reduction and hydrogen evolution reactions, with performance comparable to those of the benchmark 20wt% Pt/C, as well as good catalytic activity for oxygen evolution reaction, with a performance rivaling that of RuO2. The high catalytic performance of Co3C/Co-N-C/G makes it a promising candidate for energy conversion and storage devices.