Strategic Modulation of Target-Specific Isolated Fe,Co Single-Atom Active Sites for Oxygen Electrocatalysis Impacting High Power Zn–Air Battery
Subhajit Sarkar, Ashmita Biswas, Erakulan E. Siddharthan, Ranjit Thapa, Ramendra Sundar Dey
Abstract
An effective modulation of the active sites in a bifunctional electrocatalyst is essentially desired, and it is a challenge to outperform the state-of-the-art catalysts toward oxygen electrocatalysis. Herein, we report the development of a bifunctional electrocatalyst having target-specific Fe–N4/C and Co–N4/C isolated active sites, exhibiting a symbiotic effect on overall oxygen electrocatalysis performances. The dualism of N-dopants and binary metals lower the d-band centers of both Fe and Co in the Fe,Co,N–C catalyst, improving the overpotential of the overall electrocatalytic processes (ΔEORR-OER = 0.74 ± 0.02 V vs RHE). Finally, the Fe,Co,N–C showed a high areal power density of 198.4 mW cm–2 and 158 mW cm–2 in the respective liquid and solid-state Zn–air batteries (ZABs), demonstrating suitable candidature of the active material as air cathode material in ZABs.