Molten Salts–Assisted Fabrication of Fe, S, and N Co-Doped Carbon as Efficient Oxygen Reduction Reaction Catalyst

Fabrication of an oxygen reduction reaction (ORR) catalyst is the key to an efficient and fast electrocatalytic process in a fuel cell for energy conversion. A reasonable strategy for the synthesis of electrocatalysts is one of the most promising ways for developing precious metal-free ORR catalysts. Herein, the synthesis of a highly active Fe 3 O 4 -based catalyst using a facile molten salts method is proposed. The electrocatalytic analysis shows superior ORR performance with an admirable half-wave potential ( E 1/2 = 0.83 V), comparable with the commercial 20 wt% Pt/C. In contrast, primary Zn–air battery, using synthesized Fe,S–N–C as an air-cathode, displays an open-circuit potential of 1.44 V and a high power density of 84.3 mW cm −2 .