共查询到18条相似文献,搜索用时 125 毫秒
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采用溶胶凝胶法制备了纯TiO2和掺杂质量分数为5%,7%和9%CuO的TiO2纳米粉体,并对样品进行了不同温度(500,700和900℃)的退火处理。通过涂敷法制备成气敏元件,利用XRD和SEM对样品的结构和表面形貌进行了表征,并利用气敏测试系统检测其气敏特性。研究了CuO掺杂质量分数和退火温度对TiO2厚膜气敏性能的影响,进一步讨论了TiO2厚膜的气敏机理。结果表明:CuO的掺杂有效抑制了TiO2晶粒的生长,增加了对光子的利用率,降低了工作温度,提高了气敏特性。700℃退火后,质量分数为7%的CuO掺杂TiO2样品的结晶尺寸达到14.5 nm,气敏元件表现出对丙酮蒸汽单一的选择性,灵敏度为3 567,响应和恢复时间均为2 s。 相似文献
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根据霍耳效应,用真空镀膜法制备之SnO2厚膜,制备了NO2新型气敏元件,并对其气敏性能进行了测试。结果表明:在一定的温度和湿度下,即使没有加热,元件对体积分数为20×10–6的NO2气体的灵敏度可达5.94,响应时间为36 s,恢复时间为22 s。因此,利用霍耳效应来制作气敏元件是一条可行的新思路。 相似文献
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制备工艺对厚膜SnO_2气敏元件性能的影响 总被引:6,自引:1,他引:5
采用平面丝网印刷技术制备不同厚度的 Sn O2 厚膜气敏试样 ,在不同温度下进行热处理后 ,测量试样对乙醇气体的灵敏度 ,研究热处理温度及敏感膜厚度等对元件性能的影响。结果表明 ,热处理温度和膜厚的均匀性会影响元件的电阻值和灵敏度 ,准确控制热处理温度和膜厚能显著改善元件的灵敏度和一致性。 相似文献
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采用高温固溶工艺制备了Al3+,Fe3+和Ag+掺杂的T-ZnO气敏材料,并制作了烧结型厚膜气敏元件,测试了元件对H2S,NH3,C2H5OH和H2的敏感特性,研究了掺杂剂、掺杂工艺和材料形貌结构对T-ZnO材料气敏特性的影响规律。结果显示,T-ZnO材料对H2S和C2H5OH气体灵敏度较高,对H2和NH3等气体灵敏度较差;经过H2气氛热处理,掺物质的量百分数为0.1%Al3+的T-ZnO对气体表现出很高的灵敏度,在268.5℃时,对体积分数为10-4的H2S的灵敏度达160;同时,Al3+掺杂工艺改善了材料对H2S和C2H5OH的恢复-响应特性。在Fe3+掺杂ZnO样品中,出现第二相(ZnFe2O4)可以提高对气体的灵敏度。 相似文献
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为了改善有机半导体材料CuPc的气敏性能,采用溶液法制备了含有不同量ZnO的CuPc/ZnO杂化材料。利用SEM、XRD等测试手段对所制CuPc/ZnO杂化材料进行了表征,并研究了其气敏性能。结果表明:当质量分数w(ZnO)为10%时,CuPc/ZnO杂化材料对Cl2的灵敏度最佳;与未杂化的CuPc相比,其在175℃的最佳工作温度下对体积分数为10×10–6的Cl2的灵敏度提高了1.79倍;另外,该材料对更低浓度的Cl2也具有良好的响应,在175℃温度下,其对体积分数为1×10–6的Cl2的灵敏度为5.3;CuPc/ZnO杂化材料对Cl2具有良好的选择性和响应特性,但恢复时间较长。 相似文献
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微球状ZnO纳米粉体的制备与气敏性能研究 总被引:2,自引:1,他引:1
以Zn(CH3COO)2·2H2O为原料,无表面活性剂存在时,利用水热法合成了微球状ZnO纳米粉体。采用XRD,SEM和TEM等测试手段,对其物相、结构进行了表征。结果表明:此粉体为六方晶系的ZnO,结晶良好,直径小于4μm。利用该粉体制成气敏元件,并用静态配气法测试了元件的气敏性能。研究发现:元件在180℃工作温度下,对体积分数为50×10–6的丙酮和乙醇气体的灵敏度分别达到5.9和8.6。 相似文献
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This paper reports the novel sensing, morphological, and optical properties of indium (In)-doped ZnO films. A sol–gel dip-coating technique was used to synthesize the samples, and indium (In) in variable concentrations (2.0%, 2.5%, 3.0%, 3.5%) was used as a dopant (samples IZ-1, IZ-2, IZ-3, and IZ-4, respectively). These synthesized samples were analyzed by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), UV–Vis spectroscopy, and photoluminescence (PL) spectroscopy. Characterization studies revealed that the prepared films were highly crystalline, with a hexagonal wurtzite structure, and possessed good optical properties. FESEM images showed nanoparticle size in the range of 85–124 nm. An optical band gap in the range of 3.20–3.31 eV was obtained by UV–Vis spectroscopy. To determine the potential for use in smart nanoscale devices, synthesized In-doped ZnO was coated onto glass substrate and further characterized for its ability to sense NO2 gas. These films can play an important role in gas sensing applications. Interestingly, the sensitivity of the prepared films was found to improve with an increase in the volume of NO2 gas concentration from 2% to 4%, while a subsequent increase to 5–6% volume did not lead to further enhancement of gas sensing response. The maximum response (95.10%) was found at 4% vol of NO2 gas. Thus the optimal concentration of indium (3.0%) shows a maximum response. The prepared films were found to have a quick response time of 65 s and a fast recovery time of 87 s. 相似文献
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ZnO nanofibers were electro‐spun from a solution containing poly 4‐vinyl phenol and Zn acetate dihydrate. The calcination process of the ZnO/PVP composite nanofibers brought forth a random network of polycrystalline würtzite ZnO nanofibers of 30 nm to 70 nm in diameter. The electrical properties of the ZnO nanofibers were governed by the grain boundaries. To investigate possible applications of the ZnO nanofibers, their CO and NO2 gas sensing responses are demonstrated. In particular, the SnO2‐deposited ZnO nanofibers exhibit a remarkable gas sensing response to NO2 gas as low as 400 ppb. Oxide nanofibers emerge as a new proposition for oxide‐based gas sensors. 相似文献
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