Three-dimensional entangled and twisted structures of nitrogen doped poly-(1,4-diethynylbenzene) chain combined with cobalt single atom as a highly efficient bifunctional electrocatalyst

The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have been explored extensively for various energy conversion and storage system. Development of metal single atom doped well designed carbon substrates are considered as a new effective strategy to enhance catalytic activity and stability, and focused on as promising air cathode materials for metal-air battery. In this work, we report a novel method to fabricate cobalt (Co) single-atom species supported on porous carbon substrate using poly-(1,4-diethynylbenzene) (PDEB) chain as a new carbon substrate. Nitrogen doped PDEB chain combined with cobalt single-atom (Co-N-PDEB) shows excellent ORR and OER bifunctional catalytic performance with 1.08 V of oxygen electrode activity due to the synergistic effect between unique meso and macroporous carbon matrix with doped Co-N₄ moiety. Finally, Co-N-PDEB air cathode adopted hybrid sodium (Na) air battery exhibits outstanding charge-discharge characteristics with low overpotential gap (0.296 V) and high round trip efficiency (91.02 %).