S-doped SnO2 nanoparticles with a smaller grain size for highly efficient detection of greenhouse gas hexafluoroethane
Jianwang He, Meng Hu, Xiaoxin Wang, Yan Xu, Liang Feng
Abstract
Hexafluoroethane (CF 3 CF 3 ) is a significant greenhouse gas and a potential threat to the environment as emissions increase. However, there is no simple and effective method to detect CF 3 CF 3 yet. Hence, we first attempted to use metal oxide semiconductor (MOS) gas sensors for CF 3 CF 3 detection. Pristine SnO 2 and S-doped SnO 2 (1–3, representing different S contents) nanoparticles were synthesized. S elements successfully doped into the crystal structure of SnO 2 . The optimized sensor (S-SnO 2 -2) shows excellent CF 3 CF 3 sensing performance at 200 °C. The response value of the S-SnO 2 -2 sensor to 25 ppm CF 3 CF 3 at 200 °C is 13.44, which is significantly higher than the pristine SnO 2 response value of 4.45. The S-SnO 2 -2 sensor also exhibits a short response and recovery time (10 s and 148 s), reliable linear response, excellent selectivity , low limit of detection (0.5 ppm), satisfactory reparability, and good long-term stability. The sensing process of CF 3 CF 3 has been investigated by means of gas chromatography-mass spectrometry (GC-MS). The excellent sensing performance of CF 3 CF 3 in the S-SnO 2 -2 sensor can be attributed to the abundant active oxygen, excellent electron capture capability, and fast charge transfer of S-SnO 2 -2, which also benefits from its smaller grain size . This work is the first to report CF 3 CF 3 sensing using MOS gas sensors and has developed a feasible way for CF 3 CF 3 detection.