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 (C₄F₇N) has been utilized in various gas insulated equipment. Considering the biological toxicity of C₄F₇N, it is of great engineering significance to develop highly sensitive sensors for leakage detection scenarios. Herein, we fabricated the first SnO₂ nanoparticles based highly sensitive C₄F₇N gas sensor that realized a superior response of 65.01% within 21 s for 50 ppm C₄F₇N 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 SnO₂ nanoparticles towards C₄F₇N 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 C₄F₇N that promotes the detection response, which was also confirmed by sensing experiments for SnO₂ with different O vacancy density. We believe this paper provides convincing support for lowering the potential operation risk brought by C₄F₇N in electrical engineering and the application scenarios of SnO₂ based gas sensors.