Efficient Photocatalytic Degradation of Potent Greenhouse Gas Sf6 at Liquid-Solid Interface

Abstract

SF6, widely used in industries, poses a significant threat as the strongest greenhouse gas. Current degrading SF6 methods were hindered by high energy consumption and costs, therefore urgently need a low-cost, convenient, and efficient solution. In response to this, we established a gas-liquid-solid three-phase system to efficiently photocatalytic SF6 degradation by Bi2O2CO3, whose efficiency is approximately 20 times that of traditional gas-solid systems. Further, possible degradation mechanisms were demonstrated through the detection of material changes in three phases, respectively. Detailed studies reveal Bi2O2CO3 can form an n-n junction with in-situ generated Bi2S3 during reaction, which can facilitate carrier separation. Besides, O2 in air can transform to ·O2− and accelerate the photodegradation process. This approach offered a novel toolbox for SF6 degradation. We predict this method will have a wider range of applications in the field of solar-powered catalytic degradation of extremely stable fluorinated pollutants at lower costs in the future.

Keywords: photocatalyst, gas-liquid-solid, three-phase interfaces, SF6/air system, Bi2O2CO3