| For the reason of that nanomaterials have the properties of quantum size effect, surface and interface effect, small size effcct, they have had great application and development values in the fileds of thermotics, optical, electrical, catalysis etc. Mesoporous metal oxides with large specific surface area were successfully prepared by sol-gel method. Its gas sensing properties were studied, which were doped with metal oxide and noble metal. One dimensional TiO2 nanotubes were synthesized by anodic oxidation. The gas sensing properties of nannotubes were determined.TiO2-SnO2 composite mesoporous oxides were synthesized by evaporation induced self-assembly process. Its pore size and diameter of nano particle were about 5nm and 6nm respectively. The results indicated the sensitivities of TiO2 gas sensors increased with SnO2 doped, while the initial operating temperature towards alcohol decreased. The gas sensing properties of mesoporous oxides toward alcohol were higher than hydrogen. The sensitivity of 20%-TiO2 and pure SnO2 gas sensors toward 5×10-4 alcohol were 13.24 and 14.26 in the working temperature of 250℃, respectively.In2O3-SnO2 composite mesoporous oxides were prepared by sol-gel and the effect of In2O3 doping on gas sensing properties were studied. The result showed maximum sensitivity was observed for 80%In2O3-doped. The working voltage reduced to 25mV and the initial operating temperature descended to 100℃. The sensitivity of gas sensors increased linearly with the volum fraction of hydrogen increased.The gas sensing properties of SnO2 sensors were tested by static gas distribution. The results indicated the initial temperature of SnO2 sensors doping with Pd dropped to 125℃, the sensitivity of Pd-doped SnO2 decreased when working temperature is above a certain value. The film (0.5%) showed the highest sensitivity of 22.6 to 10-3 hydrogen at the operating temperature of 175℃.The ordered TiO2 nannotubes were prepared by anodic oxidation. The critical factors of gas sensing, for instance, calcination atmosphere, film thickness, working temperature were analyzed. The sensitivity of nanotubes calcinated in air at 500℃is greater than calcinated in nitrogen. At the anodic voltage of 20V, the nanotubes could reach 900nm within 3 hours. The sensitivity of nannotube towards 10-3 hydrogen was 2.59 at the optimum operating temperature of 125℃.
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