【摘要】：氣體傳感器的氣敏特性主要取決于其氣敏材料的性能。對(duì)于已應(yīng)用于生產(chǎn)生活中的金屬氧化物半導(dǎo)體氣敏膜的改性與修飾鮮有報(bào)道。本文則從此出發(fā),選取已應(yīng)用于工業(yè)生產(chǎn)中的SnO_2氣敏膜、WO_3氣敏膜和Pd-SnO_2氣敏膜作為改性修飾對(duì)象,對(duì)SnO_2氣敏膜、WO_3氣敏膜采用有機(jī)小分子半導(dǎo)體酞菁銅進(jìn)行了改性,對(duì)Pd-SnO_2氣敏膜采用聚偏氟乙烯微孔膜進(jìn)行了宏觀結(jié)構(gòu)修飾。本文主要研究?jī)?nèi)容如下:工作中通過浸漬組裝過程制備了CuPcTS/SnO_2復(fù)合膜。P型的CuPcTS分子均勻的吸附在n型的SnO_2膜表面并形成了p-n異質(zhì)結(jié)。由于將CuPcTS分子對(duì)NO_2在低溫下的高吸附能力結(jié)合了SnO_2膜的高電導(dǎo)率和優(yōu)良的穩(wěn)定性,因此CuPcTS/SnO_2復(fù)合膜氣敏性能表現(xiàn)出了顯著的提升,并對(duì)ppb級(jí)別的NO_2有高靈敏度和高選擇性。CuPcTS/SnO_2復(fù)合膜對(duì)1 ppm NO_2的響應(yīng)值為2400幾乎是原始SnO_2膜的24倍。基于最小平方法所擬合的線性關(guān)系,CuPcTS/SnO_2復(fù)合膜的檢測(cè)極限(信噪比為3)接近40 ppb。此外,CuPcTS/SnO_2復(fù)合膜的NO_2選擇性也顯著的提高了。純SnO_2膜對(duì)1 ppm NO_2的響應(yīng)值分別是50 ppm CO和SO_2的5倍和10倍。然而,在相同濃度下復(fù)合膜的響應(yīng)值分別是60和50倍。CuPcTS/SnO_2復(fù)合膜對(duì)ppb級(jí)NO_2超高的靈敏度和選擇性表明了其在室內(nèi)和室外檢測(cè)NO_2濃度避免空氣污染方面的光明前景。同樣通過浸漬組裝過程制備了CuPcTS/WO_3復(fù)合膜。CuPcTS/WO_3復(fù)合膜氣敏性能與CuPcTS/SnO_2復(fù)合膜一樣表現(xiàn)出了顯著的提升,并對(duì)ppb級(jí)別的NO_2有高靈敏度和高選擇性。CuPcTS/WO_3復(fù)合膜對(duì)0.1 ppm NO_2的響應(yīng)值為92是原始WO_3膜的5.4倍。基于最小平方法所擬合的線性關(guān)系,CuPcTS/WO_3復(fù)合膜的檢測(cè)極限(信噪比為3)接近70 ppb。CuPcTS/WO_3復(fù)合膜的NO_2選擇性同樣獲得顯著的提高。實(shí)驗(yàn)測(cè)得WO_3膜對(duì)0.1 ppm NO_2靈敏度分別是50 ppm CO和SO_2的13倍和10倍,但在相同的濃度下的Cu Pc/WO_3復(fù)合膜響應(yīng)分別是83和90倍。通過SnO_2膜與WO_3膜氣敏性能提高可以看出,Cu Pc可以在顯著提升室溫下n型金屬氧化物半導(dǎo)體對(duì)NO_2的靈敏度與選擇性。這種選擇性的提升是由于Cu Pc分子在金屬氧化物表面與金屬氧化物形成電子轉(zhuǎn)移通道,導(dǎo)致NO_2在Cu Pc分子表面的吸附與解吸會(huì)導(dǎo)致金屬氧化物半導(dǎo)體內(nèi)部的電子轉(zhuǎn)移導(dǎo)致材料的氣敏性能獲得提升。通過超聲輔助法制得了Pd-SnO_2納米顆粒,實(shí)驗(yàn)檢測(cè)發(fā)現(xiàn)材料在0RH%150℃下具有良好的H_2檢測(cè)性能,但Pd-SnO_2的氣敏性能隨空氣濕度增加嚴(yán)重下降,其在100 RH%下對(duì)50 ppm H_2會(huì)損失70%的靈敏度,并隨檢測(cè)氣體濃度增加,其靈敏度損失增加,至500 ppm時(shí)其靈敏度損失達(dá)到82%。采用相分離方法,在Pd-SnO_2氣敏膜表面沉積出多孔PVDF膜以改良其在高濕度空氣下的表現(xiàn)。經(jīng)檢測(cè),具有PVDF-Pd-SnO_2氣敏膜所具有的抗?jié)衲芰ο鄬?duì)比PdSnO_2氣敏膜具有良好的提升,其在100 RH%下靈敏度損失為22%并且其靈敏度損失隨H_2濃度降低,至500 ppm時(shí)其靈敏度損失為12%,但PVDF-Pd-SnO_2氣敏膜同樣具有整體靈敏度低的缺陷,相對(duì)于Pd-SnO_2氣敏膜其在干燥環(huán)境下靈敏度降低了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，

本文編號(hào)：2496479