Vacuum-Deposited Thin Film of Aniline–Formaldehyde Condensate/WO3·nH2O Nanocomposite for NO2 Gas Sensor

Research paper by Ashutosh Tiwari, Mani Prabaharan, Ravi R. Pandey, Songjun Li

Indexed on: 07 Apr '10Published on: 07 Apr '10Published in: Journal of Inorganic and Organometallic Polymers and Materials


A hydrated tungsten oxide (WO3·nH2O)-embedded aniline–formaldehyde condensate (AFC/WO3·nH2O) nanocomposite thin film was prepared on an indium tin oxide (ITO)-coated glass surface via vacuum-deposition technique. The resulting AFC/WO3·nH2O/ITO thin film was characterized using ultraviolet–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), and electron microscopy (SEM). The composite thin film exhibited a crystalline surface morphology containing nanocrystals of WO3·nH2O with a diameter ranging from 15 to 20 nm. The AFC/WO3·nH2O/ITO film allowed for the low potential detection of NO2 gas at a concentration range from 0 to 9000 ppm. The NO2 gas sensing characteristics were studied by measuring the change in the current with respect to concentration and time. The current of the AFC/WO3·nH2O/ITO film linearly increased with an increase in concentration of NO2 gas with a response of ~20 s.