Exploiting sensor geometry for enhanced gas sensing properties of fluorinated carbon nanotubes under humid environment

Modification of the surface electronic properties of vertically aligned and randomly distributed carbon nanotubes and the hydrophobic character after exposure to Ar:F-2 and CF4 plasma are exploited to optimize the sensing characteristics of these materials. The sensing properties of fluorinated carbon nanotubes are disclosed by probing their stability and responsiveness towards the detection of two selected pollutants such as nitrogen dioxide and ammonia (NO2 and NH3). The effects of both humidity level and geometry of the sensing layer are assessed. It is demonstrated that fluorination, by increasing the surface hydrophobicity, results in increased response reproducibility and enhanced sensor response towards NH3 when using vertically aligned carbon nanotubes.