Cobalt, nitrogen-codoped carbon quantum dots as a synergistic catalyst for oxygen reduction reaction

Abstract

A cobalt/nitrogen/carbon (Co/N/C) electrocatalyst has been successfully synthesized by the solvothermal method using cobalt acetate (Co(Ac)2), NH3·H2O and carbon quantum dots (CQDs) as the starting materials. The oxygen reduction reaction (ORR) activity of Co/N/C is better than single nitrogen-doped CQDs (NC) or cobalt-doped CQDs in terms of the onset potential and peak potential. The Co/N/C catalyst also exhibits better methanol durability and stability compared to the commercial Pt/C (20%). The electron-transferred number of Co/N/C for ORR is calculated to be about 3.51, indicating a four-electron pathway. Such a novel and high-efficient codoped carbon-based catalyst could be a promising substitute for commercial Pt/C in fuel cells as well as other energy storage and conversion systems.