A Ph-Universal Orr Catalyst with S Heteroatom Doping Single-Atom Iron Sites Derived from a 2d Flake-Like Mof for Superior Flexible Quasi-Solid-State Rechargeable Zn–Air Battery

Abstract

Regulating the atomic coordination ambiance of uniformly distributed single atoms via heteroatom-doping is an up-and-coming method to facilitate the catalytic activity for oxygen reduction reactions. Here, we explore a fresh approach to generate N, S co-doped Fe-SA in embedded porous carbon nanosheets/carbon nanotubes (Fe-NX@NSCST-ZL) utilizing a 2D leaf-shaped MOF as a template. Taking advantage of the combined effect of carbon matrix and nanotubes as well as the abundance of Fe-NX active sites and thiophene-S, Fe-NX@NSCST-ZL provides exceptional performance for ORR with a half-wave potential of 0.95 V at alkaline conditions, 0.77 V at acidic conditions, and 0.74 V at neutral conditions (V vs. RHE). Furthermore, Fe-NX@NSCST-ZL-based Zn-air battery and quasi solid-state flexible battery maintain steady operation for 765 h and 30 h with a small discharge/charge interval, respectively. This work contributes perspectives on the reasonable design of economical single-atom catalysts for applications in energy conversion that have outstanding electrocatalytic potential.

Keywords: Oxygen reduction reaction, Fe-NX active sites, Thiophene-S, Zn-air batteries, Solid-state flexible batteries