SnO2 nanoparticles based highly sensitive gas sensor for detection of C4F7N: A new eco-friendly gas insulating medium

As a novel eco-friendly gas insulation medium, perfluoroisobutyronitrile (C 4 F 7 N) has been utilized in various gas insulated equipment. Considering the biological toxicity of C 4 F 7 N, it is of great engineering significance to develop highly sensitive sensors for leakage detection scenarios. Herein, we fabricated the first SnO 2 nanoparticles based highly sensitive C 4 F 7 N gas sensor that realized a superior response of 65.01% within 21 s for 50 ppm C 4 F 7 N exposure and a detection limit of 0.25 ppm. Meanwhile, successive response-recovery tests were performed to confirm its durability and stability. We also explored the sensing mechanism of SnO 2 nanoparticles towards C 4 F 7 N and explained the superior sensing performance compared with other gases based on the density functional theory . It was found that the O vacancy demonstrates strong interaction with the -CN group in C 4 F 7 N that promotes the detection response, which was also confirmed by sensing experiments for SnO 2 with different O vacancy density. We believe this paper provides convincing support for lowering the potential operation risk brought by C 4 F 7 N in electrical engineering and the application scenarios of SnO 2 based gas sensors.