Deflagration method synthesizing N, S co-doped oxygen-functionalized carbons as a bifunctional catalyst for oxygen reduction and oxygen evolution reaction

Abstract

Abstract Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are the main reaction processes in metal-air batteries, fuel cells, and water electrolysis devices. It is of great significance to develop highly efficient and low-cost bifunctional catalysts for these two reactions. In this study a rapid deflagration method was reported by using Vulcan XC/72 carbon black, sublimated sulfur, potassium nitrate, urea and ammonium nitrate as raw materials to fast synthesize N and S co-doped and oxygen-functionalized carbon materials (D-NSOCs) in one step. The prepared D-NSOCs electrocatalyst exhibits excellent ORR and OER bifunctional catalytic reactivity with a small potential gap (ΔE) of 0.77\xa0V between the corresponding potential when the OER current density reaches 10\xa0mA\xa0cm−2 (Ej\xa0=\xa010) and the half-wave potential (E1/2), which is slightly better than 0.78\xa0V for the commercial Pt/C\xa0+\xa0IrO2. This deflagration method is generally applicable to other carbon materials. It can dope nitrogen and sulfur elements into carbon materials and realize the functionalization of oxygen on the surface of carbon materials.