Co4N nanoparticles encapsulated in N-doped carbon box as tri-functional catalyst for Zn-air battery and overall water splitting

The rational design of high-performance tri-functional electrocatalysts plays an important role for the fast development of Zn-air batteries (ZABs) and water splitting and still remains a great challenge up to date. Herein, Co4N nanoparticles encapsulated in nitrogen doped carbon (Co4N@NC) composite has been conveniently fabricated which shows excellent stability over 750 h at 5 mA cm(-2) and the voltage gap remain almost constant for long cycles. Flexible ZABs assembled based on this catalyst can be normally charged/discharged at any bent angles. Co4N@NC also can be used as HER catalyst to derive efficient splitting water under the ZABs which are assembled with Co4N@NC as ORR/OER catalyst. Density functional theory calculations reveal that N-doping in Co crystal could improve electronic conductivity, decrease the overpotential and accelerate reaction kinetics for OER/ORR. The above results indicate that Co4N@NC can be used as promising tri-functional high performance catalyst for Zn-air battery and overall water splitting.