Rectified SiC-Fe2O3 heterostructures for high efficient activation and degradation of sulfur hexafluoride in air atmosphere

Abstract

Sulfur hexafluoride (SF6) has a global warming potential of 23,900 CO2 equivalent during 100 years and is the strongest greenhouse gas. Therefore, it is essential to develop a degradation method for SF6. The space charge region in heterojunctions can form charged active sites, thus facilitating the absorption and decomposition of SF6 molecules. Herein, rectified SiC-Fe2O3 heterostructures were designed and in-situ generated from SiC-FeOOH composites during the thermal degradation of SF6. The heterostructures can completely decompose 2 vol% SF6 in air atmosphere at 700 °C, and have a higher initial degradation ratio of 93.6% and a degradation amount of 99.0 mL g−1. Detailed characterizations reveal that electron donor SiC can facilitate the absorption of SF6 molecules via electrostatic attraction, and the electron acceptor Fe2O3 can offer electrons to SF6 molecules to break S-F bonds. The concept of such heterostructures makes it possible to deal with large-scale leaks of low-concentration SF6.