Enhancement of sensor response of as fabricated SWCNT sensor with gold decorated nanoparticles

Here we have reported gas sensor properties of pristine single walled carbon nanotubes (SWCNTs) and Gold (Au) nanoparticles decorated SWCNT sensor towards trace level concentration detection of NH3 (40 ppm) at an operating temperature of (40 °C). Random network of SWCNTs were successfully synthesized by plasma enhanced chemical vapor deposition (PECVD) technique at a temperature of (650 °C). Two varied sets of chemiresist sensors were fabricated. One set of sensors was pristine SWCNT and the other set was decorated with Au nanoparticles by simple cast effective spray coating method. Morphological study was done by FESEM and HRTEM which revealed the excellent growth of SWCNTs and proper decoration of Au nanoparticles. The diameter distribution was confirmed by Raman Spectroscopy. The sensor response performances of both the fabricated set of sensors were analyzed and compared. The Au nanoparticles decorated SWCNT sensor had shown excellent enhancement in sensitivity. Fast response, speedy recovery, high resistance variation, high quality repeatability, long term stability and excellent selectivity was observed by Au decorated SWCNT sensor as compared to pristine SWCNT sensor for the NH3 detection. In addition of this, the sensor response and response recovery time has shown an increase with the increasing rate of target gas concentration. The sensor response also shows a decrease with increasing relative humidity.