A flexible NO2 gas sensor based on polypyrrole/nitrogen-doped multiwall carbon nanotube operating at room temperature

• Published in: Sensors and actuators. B, Chemical Vol. 295; pp. 86 - 92
• Main Authors: Liu, Bohao, Liu, Xueyan, Yuan, Zhen, Jiang, Yadong, Su, Yuanjie, Ma, Jinyi, Tai, Huiling
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15-09-2019; Elsevier Science Ltd
• Subjects: Annealing; Annealing treatment; Detection; Gas sensors; Multi wall carbon nanotubes; N-MWCNTs; Nitrogen dioxide; NO2 gas sensor; Polypyrrole; Polypyrroles; Relative humidity; Room temperature; Room temperature sensing; Selectivity; Self-assembly; Sensors; Substrates; Room temperature sensing; N-MWCNTs; NO2 gas sensor; Annealing treatment; Polypyrrole
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2019.05.065

•PPy/N-MWCNT gas sensor after annealing treatment was synthesized for NO2 sensing.•The response of optimal hybrids exhibited 44.12 times than that of unannealed one.•The effect of annealing treatment on NO2 sensing was discussed.
A flexible NO2 gas sensor based on a polypyrrole/nitrogen-doped multi-walled carbon nanotube (PPy/N-MWCNT) composite film was successfully prepared on PI substrates using a combined in situ self-assembly and annealing treatment method. After annealing at 350 °C, the gas sensor exhibited a high response of 24.82% ((Rg−Ra)/Ra×100%) under 5 ppm of NO2, which is 44.12 times greater than that of the unannealed sensor. The PPy/N-MWCNT gas sensor exhibited excellent repeatability, remarkable selectivity, good long-term stability, and acceptable flexibility. Furthermore, the effect of the relative humidity on the gas sensing properties was examined. The excellent gas sensing performances of the sensor were attributed to the enriched adsorption sites due to degradation of the amount of stacked PPy structures on the surface of the N-MWCNTs after the annealing treatment. The results demonstrated that PPy/N-MWCNT composite films are highly promising for potential applications in the field of NO2 gas sensing.