Sandwich-like superstructure of in-situ self-assembled hetero-structured carbon nanocomposite for improving electrocatalytic oxygen reduction

Developing efficient and highly low-cost electrocatalysts for oxygen reduction reaction (ORR) is highly desirable and challenging for renewable energy devices. In this work, a novel sandwich-like heterostructured nanocomposite was facilely constructed via incorporation of Co 9 S 8 nanoclusters/Co 3 [Co(CN) 6 ] 2 nanocubes in N,S-doped carbon multilayers (Co 9 S 8 /Co 3 [Co(CN) 6 ] 2 /N,S-CMLs) by a one-pot coordination-modulated pyrolysis of a mixture containing dicyandiamide, Co(NO 3 ) 2 and Evans blue at 800 °C. The control tests demonstrated critical roles of the pyrolysis temperature played on the final morphology and shape, and discussed the formation mechanism in detail. The as-prepared catalyst exhibited appealing electrocatalytic performance for ORR with a more positive onset potential ( E onset  = 0.96 V vs. RHE) and half-wave potential ( E 1/2  = 0.87 V vs. RHE) in 0.1 M KOH electrolyte, far outperforming other home-made catalysts and commercial Pt/C. This work opens a new avenue to prepare efficient, cost-effectiveness and stable electrocatalysts in sustainable energy storage and conversion devices.