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.