Effect of TiO2 on the Gas Sensing Features of TiO2/PANi Nanocomposites

Abstract

A nanocomposite of titanium dioxide (TiO2) and polyaniline (PANi) was synthesized by in-situ chemical polymerization using aniline (ANi) monomer and TiCl4 as precursors. SEM pictures show that the nanocomposite was created in the form of long PANi chains decorated with TiO2 nanoparticles. FTIR, Raman and UV-Vis spectra reveal that the PANi component undergoes an electronic structure modification as a result of the TiO2 and PANi interaction. The electrical resistor of the nanocomposite is highly sensitive to oxygen and NH3 gas, accounting for the physical adsorption of these gases. A nanocomposite with around 55% TiO2 shows an oxygen sensitivity of 600–700%, 20–25 times higher than that of neat PANi. The n-p contacts between TiO2 nanoparticles and PANi matrix give rise to variety of shallow donors and acceptor levels in the PANi band gap which enhance the physical adsorption of gas molecules.

Application-wise nanostructuring of anodic films on titanium: a review

“…[53,54] On the other hand, rutile can also present a high dielectric constant, e, that increases with temperature, with average values in the range of 40À100 [55,56] and up to 1000 on single crystals. [57] Rutile TiO 2 with a combination of high e, temperature stability and low dielectric loss attracts attention for applications as a gate dielectric for MOSFETs (metal oxide-semiconductor field-effect transistors).…”

Effect of fabrication technique on microstructure and electrical conductivity of polyaniline-TiO 2 -PVA composite material

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Room temperature CO sensing by polyaniline/Co3O4 nanocomposite

“…14 However, most of these nanometal and metal oxide-based sensors suffer from the disadvantage of having temperature-dependent sensitivity, i.e., they require high operating temperatures, which make them impracticable for use in ambient conditions. 16 Nanocomposites of PANI with nanometals [17][18][19] or nano-metal oxides [20][21][22] have shown good sensitivity towards a variety of VOCs and gases in ambient conditions. One of the ways of achieving this is through the use of intrinsically conducting polymers (ICPs) which are able to act as a matrix for such nanoparticles.…”