金属氧化物半导体气敏膜的制备与修饰
发布时间：2019-06-10 13:14
【摘要】：气体传感器的气敏特性主要取决于其气敏材料的性能。对于已应用于生产生活中的金属氧化物半导体气敏膜的改性与修饰鲜有报道。本文则从此出发,选取已应用于工业生产中的SnO_2气敏膜、WO_3气敏膜和Pd-SnO_2气敏膜作为改性修饰对象,对SnO_2气敏膜、WO_3气敏膜采用有机小分子半导体酞菁铜进行了改性,对Pd-SnO_2气敏膜采用聚偏氟乙烯微孔膜进行了宏观结构修饰。本文主要研究内容如下:工作中通过浸渍组装过程制备了CuPcTS/SnO_2复合膜。P型的CuPcTS分子均匀的吸附在n型的SnO_2膜表面并形成了p-n异质结。由于将CuPcTS分子对NO_2在低温下的高吸附能力结合了SnO_2膜的高电导率和优良的稳定性,因此CuPcTS/SnO_2复合膜气敏性能表现出了显著的提升,并对ppb级别的NO_2有高灵敏度和高选择性。CuPcTS/SnO_2复合膜对1 ppm NO_2的响应值为2400几乎是原始SnO_2膜的24倍。基于最小平方法所拟合的线性关系,CuPcTS/SnO_2复合膜的检测极限(信噪比为3)接近40 ppb。此外,CuPcTS/SnO_2复合膜的NO_2选择性也显著的提高了。纯SnO_2膜对1 ppm NO_2的响应值分别是50 ppm CO和SO_2的5倍和10倍。然而,在相同浓度下复合膜的响应值分别是60和50倍。CuPcTS/SnO_2复合膜对ppb级NO_2超高的灵敏度和选择性表明了其在室内和室外检测NO_2浓度避免空气污染方面的光明前景。同样通过浸渍组装过程制备了CuPcTS/WO_3复合膜。CuPcTS/WO_3复合膜气敏性能与CuPcTS/SnO_2复合膜一样表现出了显著的提升,并对ppb级别的NO_2有高灵敏度和高选择性。CuPcTS/WO_3复合膜对0.1 ppm NO_2的响应值为92是原始WO_3膜的5.4倍。基于最小平方法所拟合的线性关系,CuPcTS/WO_3复合膜的检测极限(信噪比为3)接近70 ppb。CuPcTS/WO_3复合膜的NO_2选择性同样获得显著的提高。实验测得WO_3膜对0.1 ppm NO_2灵敏度分别是50 ppm CO和SO_2的13倍和10倍,但在相同的浓度下的Cu Pc/WO_3复合膜响应分别是83和90倍。通过SnO_2膜与WO_3膜气敏性能提高可以看出,Cu Pc可以在显著提升室温下n型金属氧化物半导体对NO_2的灵敏度与选择性。这种选择性的提升是由于Cu Pc分子在金属氧化物表面与金属氧化物形成电子转移通道,导致NO_2在Cu Pc分子表面的吸附与解吸会导致金属氧化物半导体内部的电子转移导致材料的气敏性能获得提升。通过超声辅助法制得了Pd-SnO_2纳米颗粒,实验检测发现材料在0RH%150℃下具有良好的H_2检测性能,但Pd-SnO_2的气敏性能随空气湿度增加严重下降,其在100 RH%下对50 ppm H_2会损失70%的灵敏度,并随检测气体浓度增加,其灵敏度损失增加,至500 ppm时其灵敏度损失达到82%。采用相分离方法,在Pd-SnO_2气敏膜表面沉积出多孔PVDF膜以改良其在高湿度空气下的表现。经检测,具有PVDF-Pd-SnO_2气敏膜所具有的抗湿能力相对比PdSnO_2气敏膜具有良好的提升,其在100 RH%下灵敏度损失为22%并且其灵敏度损失随H_2浓度降低,至500 ppm时其灵敏度损失为12%,但PVDF-Pd-SnO_2气敏膜同样具有整体灵敏度低的缺陷,相对于Pd-SnO_2气敏膜其在干燥环境下灵敏度降低了12。
[Abstract]:The gas-sensing properties of the gas sensor depend mainly on the performance of the gas-sensitive material. The modification and modification of the metal oxide semiconductor gas-sensitive film which has been applied to the production life are rarely reported. In this paper, the SnO _ 2 gas-sensitive film, the WO _ 3 gas-sensitive film and the Pd-SnO _ 2 gas-sensitive film which have been applied to the industrial production are selected as modified modified objects, and the SnO _ 2 gas-sensitive film and the WO _ 3 gas-sensitive film are modified by using the organic small-molecule semiconductor phthalocyanine copper. The macrostructure modification of the Pd-SnO _ 2 air-sensitive film was carried out by using a polyvinylidene fluoride microporous membrane. The main contents of this paper are as follows: The CuPcTS/ SnO _ 2 composite film is prepared by the process of dipping and assembling in the work. The P-type CuPcTS molecules are uniformly adsorbed on the surface of the n-type SnO _ 2 film and form a p-n heterojunction. Because the high adsorption ability of the CuPcTS molecule to NO _ 2 at low temperature is combined with the high electric conductivity and the excellent stability of the SnO _ 2 film, the gas-sensitive performance of the CuPcTS/ SnO _ 2 composite film shows a remarkable improvement, and the NO _ 2 at the ppb level has high sensitivity and high selectivity. The response of CuPcTS/ SnO _ 2 composite film to 1 ppm of NO _ 2 is almost 24 times that of the original SnO _ 2 film. The detection limit (signal-to-noise ratio) of the CuPcTS/ SnO _ 2 composite film is close to 40 ppb, based on the linear relationship of the least squares method. In addition, the NO _ 2 selectivity of the CuPcTS/ SnO _ 2 composite film was also improved. The response of pure SnO _ 2 film to 1 ppm of NO _ 2 was 5 and 10 times that of 50 ppm CO and SO _ 2, respectively. However, the response values of the composite membrane at the same concentration were 60 and 50 times, respectively. The sensitivity and selectivity of the CuPcTS/ SnO _ 2 composite membrane to the ppb level of NO _ 2 show a bright future for the detection of NO _ 2 concentration in the indoor and outdoor areas to avoid air pollution. CuPcTS/ WO _ 3 composite films were also prepared by dipping assembly process. The gas-sensing performance of CuPcTS/ WO _ 3 composite film shows a significant improvement as the CuPcTS/ SnO _ 2 composite film, and has high sensitivity and selectivity to the NO _ 2 at ppb level. The response of CuPcTS/ WO _ 3 composite membrane to 0.1 ppm of NO _ 2 was 5.4 times that of the original WO _ 3 film. The detection limit of CuPcTS/ WO _ 3 composite membrane (signal-to-noise ratio is 3) is nearly 70 ppb, based on the linear relation of the least squares method, and the NO _ 2 selectivity of the CuPcTS/ WO _ 3 composite membrane is also significantly improved. The sensitivity of WO _ 3 film to 0.1 ppm of NO _ 2 was 13 and 10 times of that of 50 ppm CO and SO _ 2, respectively, but the response of Cu Pc/ WO _ 3 composite films at the same concentration was 83 and 90 times, respectively. It can be seen that the sensitivity and selectivity of the n-type metal-oxide semiconductor to NO _ 2 at room temperature can be obviously improved by the improvement of the gas-sensing performance of the SnO _ 2 film and the WO _ 3 film. This selective increase is due to the formation of an electron transfer channel between the metal oxide surface and the metal oxide by the Cu Pc molecule, and the adsorption and desorption of the NO _ 2 on the surface of the Cu Pc molecule results in an increase in the gas sensitivity of the material due to the electron transfer inside the metal oxide semiconductor. Pd-SnO _ 2 nanoparticles were prepared by ultrasonic-assisted method. The results showed that the gas-sensing performance of Pd-SnO _ 2 was good at 0 RH%150 鈩，
本文编号：2496479
[Abstract]:The gas-sensing properties of the gas sensor depend mainly on the performance of the gas-sensitive material. The modification and modification of the metal oxide semiconductor gas-sensitive film which has been applied to the production life are rarely reported. In this paper, the SnO _ 2 gas-sensitive film, the WO _ 3 gas-sensitive film and the Pd-SnO _ 2 gas-sensitive film which have been applied to the industrial production are selected as modified modified objects, and the SnO _ 2 gas-sensitive film and the WO _ 3 gas-sensitive film are modified by using the organic small-molecule semiconductor phthalocyanine copper. The macrostructure modification of the Pd-SnO _ 2 air-sensitive film was carried out by using a polyvinylidene fluoride microporous membrane. The main contents of this paper are as follows: The CuPcTS/ SnO _ 2 composite film is prepared by the process of dipping and assembling in the work. The P-type CuPcTS molecules are uniformly adsorbed on the surface of the n-type SnO _ 2 film and form a p-n heterojunction. Because the high adsorption ability of the CuPcTS molecule to NO _ 2 at low temperature is combined with the high electric conductivity and the excellent stability of the SnO _ 2 film, the gas-sensitive performance of the CuPcTS/ SnO _ 2 composite film shows a remarkable improvement, and the NO _ 2 at the ppb level has high sensitivity and high selectivity. The response of CuPcTS/ SnO _ 2 composite film to 1 ppm of NO _ 2 is almost 24 times that of the original SnO _ 2 film. The detection limit (signal-to-noise ratio) of the CuPcTS/ SnO _ 2 composite film is close to 40 ppb, based on the linear relationship of the least squares method. In addition, the NO _ 2 selectivity of the CuPcTS/ SnO _ 2 composite film was also improved. The response of pure SnO _ 2 film to 1 ppm of NO _ 2 was 5 and 10 times that of 50 ppm CO and SO _ 2, respectively. However, the response values of the composite membrane at the same concentration were 60 and 50 times, respectively. The sensitivity and selectivity of the CuPcTS/ SnO _ 2 composite membrane to the ppb level of NO _ 2 show a bright future for the detection of NO _ 2 concentration in the indoor and outdoor areas to avoid air pollution. CuPcTS/ WO _ 3 composite films were also prepared by dipping assembly process. The gas-sensing performance of CuPcTS/ WO _ 3 composite film shows a significant improvement as the CuPcTS/ SnO _ 2 composite film, and has high sensitivity and selectivity to the NO _ 2 at ppb level. The response of CuPcTS/ WO _ 3 composite membrane to 0.1 ppm of NO _ 2 was 5.4 times that of the original WO _ 3 film. The detection limit of CuPcTS/ WO _ 3 composite membrane (signal-to-noise ratio is 3) is nearly 70 ppb, based on the linear relation of the least squares method, and the NO _ 2 selectivity of the CuPcTS/ WO _ 3 composite membrane is also significantly improved. The sensitivity of WO _ 3 film to 0.1 ppm of NO _ 2 was 13 and 10 times of that of 50 ppm CO and SO _ 2, respectively, but the response of Cu Pc/ WO _ 3 composite films at the same concentration was 83 and 90 times, respectively. It can be seen that the sensitivity and selectivity of the n-type metal-oxide semiconductor to NO _ 2 at room temperature can be obviously improved by the improvement of the gas-sensing performance of the SnO _ 2 film and the WO _ 3 film. This selective increase is due to the formation of an electron transfer channel between the metal oxide surface and the metal oxide by the Cu Pc molecule, and the adsorption and desorption of the NO _ 2 on the surface of the Cu Pc molecule results in an increase in the gas sensitivity of the material due to the electron transfer inside the metal oxide semiconductor. Pd-SnO _ 2 nanoparticles were prepared by ultrasonic-assisted method. The results showed that the gas-sensing performance of Pd-SnO _ 2 was good at 0 RH%150 鈩，
本文编号：2496479
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