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采用水热法制备了ZnO粉末和复合不同稀土离子的ZnO粉末,并通过X射线衍射谱(XRD)和扫描电镜(SEM)进行了结构和形貌表征,结果显示,ZnO材料具有六方纤锌矿的结构,稀土离子以氧化物的形式析出,纯ZnO及稀土复合的ZnO均为棒状。由气敏测试结果可看出,Sm离子的复合使纯氧化锌对甲醛、乙醇和三甲胺的灵敏度得到明显提高。Sm2O3-ZnO复合材料对1.0×10-4(体积分数,下同)的甲醛的灵敏度达到58.04,对1.0×10-3的甲醛的灵敏度达到959.60。在7种气体的干扰下,Sm2O3-ZnO复合材料显示了良好的选择性。该材料对甲醛的灵敏度是对丙酮、甲醇和乙醇的灵敏度的4倍左右。另外,Sm2O3-ZnO复合材料在300℃对1.0×10-4甲醛的响应时间和恢复时间分别为17 s和12 s。
ZnO powder and ZnO powder with different rare earth ions were prepared by hydrothermal method. The structure and morphology of ZnO powder were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the ZnO material has hexagonal wurtzite Of the structure, rare earth ions precipitated as oxides, pure ZnO and rare earth composite ZnO are rod-shaped. As can be seen from the gas-sensing test results, the composite of Sm ions makes the pure zinc oxide significantly improve the sensitivity of formaldehyde, ethanol and trimethylamine. The sensitivity of Sm2O3-ZnO composite to formaldehyde 1.0 × 10-4 (volume fraction) is 58.04, and the sensitivity to 1.0 × 10-3 formaldehyde is 959.60. The Sm2O3-ZnO composite shows good selectivity under the interference of seven gases. The sensitivity of this material to formaldehyde is about 4 times that of acetone, methanol and ethanol. In addition, the response time and recovery time of Sm2O3-ZnO composite at 300 ℃ to 1.0 × 10-4 formaldehyde were 17 s and 12 s, respectively.