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

Sensors

Duong Ngoc Huyen¹  Nguyen Trong Tung²  Nguyen Duc Thien² 

[1] Institute of Engineering Physics, Hanoi University of Science and Technology, No.1, Daicoviet, Hanoi, Vietnam;

关键词: nanocomposites;    TiO₂;    PANi;    gas sensor;   

DOI  :  10.3390/s110201924

来源: mdpi

【 摘 要 】

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.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.