Chemically synthesized TiO2 and PANI/TiO2 thin films for ethanol sensing applications. (7th February 2018)

• Record Type: Journal Article
• Authors: Gawri, Isha; Ridhi, R; Singh, K P; Tripathi, S K
• Is Part Of: Materials research express. Volume 5:Number 2(2018)
• Publication Date: 2018-02-07
• Subjects: PANI/TiO2 nanocomposite -- ethanol -- gas sensing -- in-situ polymerization -- thin film; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/aaa9f1
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: Ethanol sensing properties of chemically synthesized titanium dioxide (TiO2 ) and polyaniline/titanium dioxide nanocomposites (PANI/TiO2 ) had been performed at room temperature. In-situ oxidative polymerization process had been employed with aniline as a monomer in presence of anatase titanium dioxide nanoparticles. The prepared samples were structurally and morphologically characterized by x-ray diffraction, fourier transform infrared spectra, high resolution-transmission electron microscopy and field emission-scanning electron microscopy. The crystallinity of PANI/TiO2 nanocomposite was revealed by XRD and FTIR spectra confirmed the presence of chemical bonding between the polymer chains and metal oxide nanoparticles. HR-TEM micrographs depicted that TiO2 particles were embedded in polymer matrix, which provides an advantage over pure TiO2 nanoparticles in efficient adsorption of vapours. These images also revealed that the TiO2 nanoparticles were irregular in shape with size around 17 nm. FE-SEM studies revealed that in the porous structure of PANI/TiO2 film, the intercalation of TiO2 in PANI chains provides an advantage over pure TiO2 film for uniform interaction with ethanol vapors. The sensitivity values of prepared samples were examined towards ethanol vapours at room temperature. The PANI/TiO2 nanocomposite exhibited better sensing response and faster response-recovery examined at different ethanol concentrations ranging from 5 ppm to 20 ppm in comparison to pure TiO2 nanoparticles. The increase in vapour sensing of PANI/TiO2 sensing film as compared to pure TiO2 film had been explained in detail with the help of gas sensing mechanism of TiO2 and PANI/TiO2 . This provides strong evidence that gas sensing properties of TiO2 had been considerably improved and enhanced with the addition of polymer matrix.