Construction of Co/Co2N0.67 nanoparticles embedded S and N-doped carbon from a cobalt-complex as a bifunctional Electrocatalyst for ORR and OER
Khatun A. Jannath, Kyubin Shim, Kyeong‐Deok Seo, Yoon-Bo Shim, Deog‐Su Park, Hae Jin Kim
Abstract
Advancing impactful, economical, and durable Co-based bifunctional electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) has been crucial in developing sustainable energy technologies. In this work, Co and Co 2 N 0.67 nanoparticles (NPs)-incorporated S, N-doped carbon catalysts (Co/Co 2 N 0.67 /SNC) were prepared via direct pyrolysis of the CoDATT complex, exhibiting high bifunctional electrocatalytic performance for ORR and OER. The complex precursor, CoDATT, was synthesized for the first time using diaminoterthiophene (DATT) and CoCl 2 . The complex was directly pyrolyzed at 800 °C, followed by an acid wash to obtain the catalyst Co/Co 2 N 0.67 /SNC. The optimized catalyst displayed a low OER overpotential (η = 331 mV vs. reversible hydrogen electrode (RHE) at 10 mA cm −2 ), an excellent ORR half-wave potential (E 1/2 = 0.878 V vs. RHE), high stability, and alcohol tolerance as a bifunctional OER and ORR electrocatalyst, surpassing the activity of the benchmarks RuO 2 and Pt/C, respectively, in an alkaline medium. The high catalytic activity of the optimized catalysts can be attributed to the S, N-co-doping, as well as the synergistic effect between Co/Co 2 N 0.67 NPs and SNC, resulting in enhanced catalytic performance for both ORR and OER.