Polyaniline/γ-Fe2O3 nanocomposite for room temperature LPG sensing

Polyaniline/γ-ferric oxide (PANi/γ-Fe2O3) nanocomposite films exhibited excellent sensing ability toward LPG at room temperature. The films were studied for their response to LPG at 50-200 ppm concentrations. The nanoscale morphology of the composites provided a large surface area for the adsorption of gas molecules, thus enhancing the gas sensitivity. The sensing mechanism pertains to a change in the depletion region of the p-n junction formed between PANi and γ-Fe2O3 as a result of electronic charge transfer between the gas molecules and the sensor. The maximum response was obtained for PANi/γ-Fe2O3 (3 wt%) nanocomposite for 200 ppm LPG. The response times of these sensors were found to be as low as 60 s.