盐介质固相反应法制备纳米铁酸镧及其气敏性能

Gas-Sensing Properties of Nano-LaFeO3 Prepared by a Simple Molten-Salt Method

摘要:

以La2O3和FeCl3·6H2O为主要原料，利用盐介质固相反应法制备了LaFeO3纳米晶。用XRD、TEM分别对不同反应温度下的产品进行了物相和形貌表征，并研究了其对三乙胺、乙醇、汽油、苯和丙酮等的敏感性能。结果表明：反应温度为800 ℃时，产物为均相LaFeO3，粒度较均匀，平均粒径约为40 nm；将样品制成烧结型气敏元件，对三乙胺有较高的灵敏度和选择性，工作温度为250 ℃时对25 μg/g三乙胺的灵敏度仍达7.9，响应、恢复时间分别仅需6和13 s。

Abstract:

Nanocrystalline LaFeO3 was prepared by a simple molten-salt method with La2O3 and FeCl3·6H2O as main starting materials. The nanocrystal1ine samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) for the phases and morphology. Their gas-sensing properties to triethylamine, C2H5OH, gasoline, C6H6 and CH3COCH3 were investigated. The results demonstrated that pure LaFeO3 nanocrystal1ine with uniform grain sizes and an average diameter of about 40 nm was formed when calcined at 800 ℃. Moreover, the gas sensor made of the nanocrystalline LaFeO3 sample showed high sensitivity as well as good selectivity to dilute triethylamine. The LaFeO3 sensor showed the sensitivity as high as 7.9 to even 25 μg/g triethylamine at 250 ℃, and the response and recovery time are 6 and 13 s, respectively.