The preparation and gas sensitivity study of polythiophene/SnO2 composites

Abstract Nanocomposites of SnO 2 and polythiophene (PTP) were synthesized by the in situ chemical oxidative polymerization method. These nanocomposites were characterized by FTIR, transmission electron microscope (TEM), X-ray diffraction (XRD) and thermogravimetric and differential thermal analysis (TG–DTA) techniques, which proved the polymerization of thiophene monomer and the strong interaction between polythiophene and SnO 2 . The composites were used for gas sensing to methanol (MeOH), ethanol (EtOH), acetone, and NO x at different working temperature. It was found that PTP/SnO 2 materials with different PTP mass percent (1%, 5%, 10%, 20% and 30%) could detect NO x with very higher selectivity and sensitivity at much lower working temperature than the reported SnO 2 . The PTP/SnO 2 nanocomposites responded to NO x at concentration as low as 10 ppm. PTP/SnO 2 composite containing 5 mass% PTP showed the highest sensitivity at room temperature. The sensing mechanism of PTP/SnO 2 nanocomposites to NO x was presumed to be the effects of p–n heterojunction between PTP and SnO 2 .