Single Fe Atom on Hierarchically Porous S, N-Codoped Nanocarbon Derived from Porphyra Enable Boosted Oxygen Catalysis for Rechargeable Zn-Air Batteries

Jiting Zhang; Meng Zhang; Yan Zeng; Jisheng Chen; Lingxi Qiu; Hua Zhou; Chengjun Sun; Ying Yu; Chengzhou Zhu; Zhihong Zhu

doi:10.1002/smll.201900307

Single Fe Atom on Hierarchically Porous S, N-Codoped Nanocarbon Derived from Porphyra Enable Boosted Oxygen Catalysis for Rechargeable Zn-Air Batteries

Small. 2019 Jun;15(24):e1900307. doi: 10.1002/smll.201900307. Epub 2019 May 6.

Authors

Affiliations

¹ Institute of Nano-Science and Nano-Technology, College of Physical Science and Technology, Central China Normal University, Wuhan, 430079, China.
² Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China.
³ Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA.

PMID: 31058413
DOI: 10.1002/smll.201900307

Abstract

Iron-nitrogen-carbon materials (Fe-N-C) are known for their excellent oxygen reduction reaction (ORR) performance. Unfortunately, they generally show a laggard oxygen evolution reaction (OER) activity, which results in a lethargic charging performance in rechargeable Zn-air batteries. Here porous S-doped Fe-N-C nanosheets are innovatively synthesized utilizing a scalable FeCl₃ -encapsulated-porphyra precursor pyrolysis strategy. The obtained electrocatalyst exhibits ultrahigh ORR activity (E_1/2 = 0.84 V vs reversible hydrogen electrode) and impressive OER performance (E_j _{= 10} = 1.64 V). The potential gap (ΔE = E_j _{= 10} - E_1/2 ) is 0.80 V, outperforming that of most highly active bifunctional electrocatalysts reported to date. Furthermore, the key role of S involved in the atomically dispersed Fe-Nx species on the enhanced ORR and OER activities is expounded for the first time by ultrasound-assisted extraction of the exclusive S source (taurine) from porphyra. Moreover, the assembled rechargeable Zn-air battery comprising this bifunctional electrocatalyst exhibits higher power density (225.1 mW cm^-2 ) and lower charging-discharging overpotential (1.00 V, 100 mA cm^-2 compared to Pt/C + RuO₂ catalyst). The design strategy can expand the utilization of earth-abundant biomaterial-derived catalysts, and the mechanism investigations of S doping on the structure-activity relationship can inspire the progress of other functional electrocatalysts.

Keywords: bifunctional catalysts; biomass; heteroatom doping; rechargeable Zn-air batteries; single-atom electrocatalysts.