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纳米SmFeO3的合成及其H2S敏感特性研究 总被引:1,自引:0,他引:1
以无机物K3[Fe(CN)6]和Sm2O3为原料,用热分解配合物前驱体法制备了复合氧化物SmFeO3纳米粉体.用X-射线粉末衍射仪(XRD)和透射电镜(TEM)对产物的物相、形貌进行了表征.结果显示:热分解法在煅烧温度为600℃即可生成纳米晶SmFeO3,TEM显示产物为均匀的椭球形颗粒,充分表明该方法制备的材料具有良好分散性,且纯度较高.将合成材料制备成旁热式气敏元件,气敏性能测试结果表明:合成材料对H2S具有高的灵敏度和选择性,在最佳工作电压4 V时对50μL/L H2S气体的灵敏度可达21.3倍,相对干扰气体C2H5OH来讲其选择性系数为4.44倍.而且响应很快,约2 s,但恢复稍慢,40 s左右. 相似文献
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平面工艺SnO2薄膜甲醛气敏元件的研究 总被引:1,自引:0,他引:1
用ANSYS仿真软件得到最优化的气体传感器电极结构,采用平面工艺在硅衬底上制作了3 mm×2 mm的直热式Sn02薄膜甲醛气敏元件.用溶胶凝胶(sol-gel)法制备了掺Pd的纳米SnO2薄膜,材料的平均粒径约为15nm.元件的最佳工作温度约为230℃,在该加热温度下测试了元件对体积分数为50×10-9的甲醛气体的灵敏度以及响应恢复时间.实验证明:元件的灵敏度随气体浓度的增大而增大,元件的响应和恢复时间均约为50s. 相似文献
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以无机盐为原料,液相合成了ZnFe2O4纳米粉体,通过XRD,TEM等手段对粉体的晶体结构、形貌等进行表征并研制了厚膜型气敏元件.结果表明:产物为尖晶石结构,粒径尺寸分布为10 nm~30 nm,平均粒径约为14 nm.在40℃~400℃的温度范围内,采用静态配气法测定元件的气敏性能,发现ZnFe2O4气敏元件在150℃的工作温度下对体积比浓度为1×10-3 (V/V0)、1×10-4(V/V0)的H2S气体的灵敏度分别高达244.34和83.31;在此工作温度下对1×10-4(V/V0)的H2S气体响应时间2 s,恢复时间为5 s.在40℃对1×10-3(V/V0)的H2S气体的灵敏度达到111.00. 相似文献
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本文采用溶剂热法制备了双金属Zn-Fe金属有机框架结构(Zn-Fe MOF),利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线衍射仪(XRD)对其微观形貌和晶相进行表征分析。结果表明:制备的双金属Zn-Fe MOF为纳米球结构,其直径约为150 nm。同时,制备了基于双金属Zn-Fe MOF材料的气体传感器件,研究了其对丙酮的气敏特性。测试结果表明:基于双金属Zn-Fe MOF的气体传感器对丙酮的最佳工作温度为210 ℃。在最佳工作温度下,对浓度为1×10-6的丙酮气体响应可达到2,响应/恢复时间分别为6 s / 13 s,且具有较好的重复性和长期稳定性。最后,对基于双金属Zn-Fe MOF气体传感器的气敏机理进行了讨论。 相似文献
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采用溶胶凝胶法制备的Al掺杂ZnO纳米粉末(AZO)。利用X射线衍射(XRD)和扫描电子显微镜(SEM)表征样品的晶体结构和表面形貌。采用浸渍提拉法将该样品制成旁热式气体传感器,检测其对不同气体的响应恢复特性。结果表明:Al掺杂ZnO表面粗糙,Al的掺杂能够抑制ZnO晶粒增长。当工作温度为70℃、湿度为27%RH时,4.98wt.%Al掺杂ZnO对丙酮气体具有很好的选择性,电阻灵敏度达到了14075,响应和恢复时间分别为1 s和3 s。紫外光照射可明显提高传感器的气敏特性,并降低工作温度。 相似文献
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Zhang Tianshu P. Hing Yang Li Zhang Jiancheng 《Sensors and actuators. B, Chemical》1999,60(2-3):208-215
The effect of CdO doping on microstructure, conductance and gas-sensing properties of SnO2-based sensors has been presented in this study. Precursor powders with Cd/Sn molar ratios ranging from 0 to 0.5 were prepared by chemical coprecipitation. X-ray diffraction (XRD) analysis indicates that the solid-state reaction in the CdO–SnO2 system occurs and -CdSnO3 with pervoskite structure is formed between 600 and 650°C. CdO doping suppresses SnO2 crystallite growth effectively which has been confirmed by means of XRD, transmission electron microscopy (TEM) and BET method. The 10 mol% Cd-doped SnO2-based sensor shows an excellent ethanol-sensing performance, such as high sensitivity (275 for 100 ppm C2H5OH), rapid response rate (12 s for 90% response time) and high selectivity over CO, H2 and i-C4H10. On the other hand, this sensor has good H2-sensing properties in the absence of ethanol vapor. The sensor operates at 300°C, the sensitivity to 1000 ppm H2 is up to 98, but only 16 and 7 for 1000 ppm CO and i-C4H10, respectively. 相似文献
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Nanocrystalline gamma iron oxide (γ-Fe2O3) has been synthesized at room temperature through sonication-assisted precipitation technique. The key in obtaining γ-Fe2O3 at room temperature lies in exploiting high-power ultrasound (600 W). The gas-sensing properties to n-butane of pure γ-Fe2O3 were investigated by studying the electrical properties of the sensor elements fabricated from the synthesized powder. The maximum response (90%) of the sensor to 1000 ppm n-butane at 300 °C can be explained on the basis of catalytic activity of the nanocrystallites. The response and recovery time of the sensor to 1000 ppm n-butane were less than 12 s and 120 s, respectively. 相似文献
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α-Fe2O3 ultra-fine powder with an average particle size of 6–26nm has been prepared by a sol-gel process. Thermal analysis, X-ray diffraction and transmission electron microscope were used to study its formation process and micro-structure. The temperature dependence of the electric conductance of the elements made of nanocrystalline α-Fe2O3 shows that the gas-sensing properties are strongly related to its surface. The elements exhibited good sensitivity and selectivity to ethyl alcohol, indicating it is a promising alcohol-sensing material. 相似文献