Metal-tetraphenylporphyrin functionalized carbon nanotube thin films as sensor for detection of nitrogen dioxide vapors

Abstract

We have developed a process for functionalization of multi-walled carbon nanotubes with metal-tetraphenylporphyrin (M-TPP) and have used the material as highly sensitive sensor for detection of nitrogen dioxide vapors. Multi-walled carbon nanotubes (MWCNTs) were first functionalized using corona electrostatic discharge technique, and then a composite consisting of the functionalized CNTs and M-TPP was prepared by blending and ultrasonification in toluene solution. The nanocomposites thus prepared have been used for the detection of nitrogen dioxide (NO2) vapors with very high sensitivity. The sensors show resistivity in the kilo-ohms range with response time of few seconds but several minutes for recovery. The technique for fabrication of sensors is simple, fast and low cost and does not require any expensive or specialized equipment. The thin films can be formed on almost any substrate including glass, plastic and irregularly shaped substrates. These properties make our sensors very attractive for commercial applications for detection of NO2 vapors. © 2013 AIP Publishing LLC.