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

Duong Ngoc Huyen; Nguyen Trong Tung; Nguyen Duc Thien; Le Hai Thanh

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.

TITANIUM dioxide; ANILINE; POLYMERIZATION; SCANNING electron microscopes; ADSORPTION (Chemistry); NANOCOMPOSITE materials; SENSITIVITY analysis

Sensors (14248220), 2011, Vol 11, Issue 2, p1924

1424-8220

Academic Journal

10.3390/s110201924