Selective catalytic oxidation of pollutant H2S over Co-decorated hollow N-doped carbon nanofibers for high-performance Li-S batteries

Abstract

Hydrogen sulfide (H2S) is one of the most harmful pollutants to human health and the environment. Using carbon-based catalysts, H2S can be selectively oxidized to elemental sulfur (S) at room temperature and carbon-sulfur composites are produced, which enlightens a facile solution combining desulfurization with cathode preparation for high-performance lithium-sulfur batteries (LSBs). Herein, a heterogeneous catalyst of cobalt decorated N-doped hollow carbon nanofibers (Co-NHCFs) is designed for realizing the integrated application, in which the electron redistribution arising from long-range interactions of Co/N-doped carbon significantly promotes the oxygen radical generation and H2S dissociation, leading to its robust catalytic activity for H2S oxidation. Benefiting from the hollow framework with capacious storage space for rapid gas diffusion, the in-situ fabrication of high S-loading carbon-based cathodes (S@Co-NHCFs) used for LSBs is achieved during the H2S oxidation processing. Due to the more favorable diffusion of H2S gas than liquid S, this kind of chemical reaction-induced deposition can realize a more uniform distribution of solid S upon carbon than the traditional method by molten infusion, which, coupled with the catalysis of heterogeneous effect on the reversible sulfur-redox reaction, results in superior electrochemical performance of S@Co-NHCFs in LSBs.