Fe_2O_3/MWCNTs复合材料的制备及其NO_x气敏性能

Synthesis of Fe_2O_3/MWCNTs composites and their NO_x gas sensitivity

采用沉淀法制备了Fe2O3/MWCNTs复合材料。通过X-射线衍射分析(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等测试手段对所合成材料进行了表征。结果表明,合成的Fe2O3/MWCNTs复合材料均由碳纳米管与氧化铁颗粒组成,Fe2O3粒子尺寸较均匀,其颗粒大小约为5 nm。在室温条件下,Fe2O3/MWCNTs复合材料对NOx具有较好的气敏性能,当NOx浓度为9.7×10-7时,复合材料对NOx的灵敏度为6.13%,响应时间为38 s。分析其原因主要是合成材料中Fe2O3的主要相态是呈p型半导体特性的γ-Fe2O3,与吸附空气中氧气呈现出p型半导体特性的MWCNTs复合时产生倍增效应的结果。

Fe203/Muhi-Walled Carbon Nanotubes （MWCNTs） composites were prepared by precip- itation method. The composites were characterized by X-ray diffraction analysis （XRD） , scanning elec- tronic microscope （SEM）, transmission electron microscope （TEM）. F%O3/MWCNTs composites were composed of Fe203 particles and MWCNTs. The results showed that the size of F%O3 particles was about 5 nm and the particles were evenly distributed. NOx gas sensing properties experiments showed that Fe203/MWCNTs composites had a good gas sensing performance at room temperature. When the concen- tration of NOx is 9.7 x 10 7, the sensitivity and response time of Fe203/MWCNTs composites were about 6. 13% and 38 s, respectively. This could be attributed to multiplication effect of MWCNTs and Fe203. The main phase of Fe203 is -Fe203. -Fe203 and MWCNTs both showed p-type semiconducting proper- ties when absorbed oxgen in air.