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In recent years, due to the needs of all aspects of energy development, aerospace, petrochemical, production safety, flammable and explosive, toxic gas monitoring becomes increasingly important. Especially developed high sensitivity, good selectivity, good stability, faster recovery time, long-life gas sensors become gas sensor response important research topic. Thus, the development of new gas-sensitive materials, has practical value has become a hot research. Conductive polymer such as polythiophene, polypyrrole and polyaniline with its chemical sensors, biological sensors, electronic components, and because of their excellent mechanical and conductive properties, such as low operating temperature, low cost, ease of processing, having elasticity and the application aroused extensive attention to the potential application of low-cost sensors and solar cells. But they may also exist, such as chemical stability is low, and not conducive to the application of the conductive polymer in the relevant aspects of the shortcomings of mechanical workability and weak. Currently, the widespread use of gas-sensitive material is a semiconductor metal oxide, this material is the existence of poor selectivity, and high operating temperatures defects. To overcome the shortcomings of polymer gas-sensitive material and a metal oxide, an inorganic metal oxide, an inorganic portion, the conductive polymer is an organic portion composed of organic-inorganic hybrid gas-sensitive material, because of having a single integral component do not have mutual synergies and complementarity, conducive to enhanced gas sensing sensing nature, so as to receive widespread attention. Conducted the organic / inorganic hybrid material is used in the gas sensor, we choose polythiophene as an organic phase component, tin dioxide, tungsten trioxide and other typical metal oxide semiconductor as an inorganic component, the use of in situ oxidative polymerization different hybrid materials to be prepared, and to study the gas sensing performance of its low temperature (lt; 100 ℃), by comparison with the gas sensing performance of single material, analysis of the hybrid materials sensitive mechanism. And the use of Pt doped WO3-based material has been improved, to achieve improved gas sensitivity, selectivity, and to reduce the operating temperature of the purposes. The main research was summarized as the following aspects: 1. Situ oxidation polymerization prepared WO3/PTP hybrid materials (the PTP the quality fraction of 1%, 10%, 20%, 30% and 40%), gas sensing The test results show that WO3/PTP hybrid materials of methanol, ethanol, acetone, H2S gas or no have small gas sensitivity, good selectivity of NO2 gas. And to some extent alleviated the irreversibility of the single PTP material of NO2. The sensitivity of the WO3/PTP hybrid materials change with the change of the mass fraction of the PTP. PTP mass fraction 10%, and the operating temperature of 70 ° C, WO3/PTP hybrid materials reached the maximum sensitivity. WO3/PTP hybrid materials NO2 gas sensing mechanism pn heterojunction. 2 for the first time peptization - coprecipitation prepared Pt doped WO3-based gas sensing material (Pt mass fraction of 0.25%, 0.5%, 1.0%, 2.0%), the material of 2 hours at 600 ℃ after used for performance testing. The gas sensing performance test results show that, when the doping amount of Pt is 0.5wt%, the maximum sensitivity of the element; optimum working temperature of 120 ℃, is reduced as compared with the pure WO3 above 20 ℃. Better sensing properties of doped the W03 gas sensors Pt after the unique selectivity of H2S. 0.5wt% Pt-WO3 four months after the test results show that the sensitivity of 20 ppm H2S is still much higher than the pure of WO3, but the sensitivity dropped significantly, which reason further studies. Situ oxidative polymerization preparation hs-SnO2/PTP hybrid materials by XRD, FT-IR, TGA, TEM and other means of material characterization and study the gas sensing performance in less than 100 ℃. The experimental results are as follows: hs-SnO2 / (20%) of the PTP as the representative study found better selectivity for NO2 gas and the operating temperature is far lower than that of SnO2, and to some extent alleviate the single-PTP material on NO2 is not reversible. The sensitivity of the SnO2/PTP hybrid materials change with the change of the mass fraction of the PTP. When the PTP's mass fraction of 40%, the sensitivity of the hybrid material at 70 ℃ hs-SnO2/PTP higher. hs-SnO2/PTP hybrid materials NO2 gas sensing mechanism pn heterojunction.
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