论文部分内容阅读
采用低温固相反应法合成了NiFe2O4纳米粉体,并通过浸渍法在其表面修饰La2O3及Y2O3,通过X射线衍射分析(XRD)和扫描电镜(SEM)研究了修饰前后粉体的结构及形貌,并对修饰不同含量La2O3及Y2O3的旁热式气敏元件的气敏性进行了测试。结果表明:La2O3及Y2O3以无定形结构附着于NiFe2O4颗粒表面,当表面修饰为4%(质量分数)的La2O3时,NiFe2O4气敏元件的最佳工作温度为150℃,对1000 ppm的乙醇及丙酮气体具有较高的灵敏度。有望开发出一种低温下工作的新型气敏元件。当表面修饰2%Y2O3(质量分数)时,对1000ppm的乙醇气体的灵敏度要高于对丙酮气体的灵敏度,达到33.5,最佳工作温度为250℃。
NiFe2O4 nanopowders were synthesized by low temperature solid-state reaction. La2O3 and Y2O3 were modified on the surface by impregnation method. The structure and morphology of the powders before and after modification were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) , And the gas sensitivities of modified side-heated gas sensors with different contents of La2O3 and Y2O3 were tested. The results show that La2O3 and Y2O3 adhere to the surface of NiFe2O4 particles with amorphous structure. When the surface modification is 4% (mass fraction) of La2O3, the optimal working temperature of NiFe2O4 gas sensor is 150 ℃. For 1000 ppm ethanol and acetone Gas has high sensitivity. It is expected to develop a new type of gas sensor working at low temperature. When the surface modification of 2% Y2O3 (mass fraction), the sensitivity of 1000ppm of ethanol gas is higher than the sensitivity of acetone gas, reaching 33.5, the best working temperature is 250 ℃.