Nitrogen-doped carbon sheets derived from chitin as non-metal bifunctional electrocatalysts for oxygen reduction and evolution

Abstract

Affordable, efficient electrocatalysts for oxygen reduction reactions (ORR) and oxygen evolution reactions (OER) are critical for various energy technologies. Herein, we report that an activated carbon sheet (ACS) derived from chitin is an efficient non-metal bifunctional electrocatalyst for both ORR and OER. In alkaline media, the as-prepared ACS exhibited remarkable electrocatalytic activity for the oxygen reduction reaction, which was significantly superior to an unactivated carbon sheet (CS) and comparable to the commercial Pt/C catalyst with excellent durability and resistance to the crossover effect. Meanwhile, the same ACS also presents high catalytic activity towards OER, with a small overpotential of ∼1.64 ± 0.02 V versus RHE. The excellent electrocatalytic properties of the ACS originated from the combined effect of optimal nitrogen doping, high surface area, and porous architecture. This work demonstrates that the ACS is a promising material candidate with high-performance in electrocatalytic applications in energy technologies.