本文選題：氣體傳感器 + 摻雜　； 參考：《吉林大學(xué)》2017年碩士論文

【摘要】：隨著社會的不斷發(fā)展與科技的不斷進(jìn)步,人們也越來越看重生活質(zhì)量。在日常生活中難免會遇到一些有毒有害、易燃易爆氣體,會對人身和財產(chǎn)造成危害。這時,氣體傳感器就會起到一個非常重要的作用,它能夠及時的檢測環(huán)境中的氣體氛圍。如今,科研工作者們致力于研制高性能、快速響應(yīng)恢復(fù)和高選擇性的氣體傳感器。在眾多氣體傳感器中,金屬氧化物半導(dǎo)體式氣體傳感器是目前最主要的一種氣體傳感器。它有著制備工藝簡單、成本低、氣敏性能很好等優(yōu)點。目前,人們嘗試不同的方法來合成氧化物半導(dǎo)體材料。而純的氧化物半導(dǎo)體材料在氣體傳感器上的應(yīng)用,存在著一些缺陷,如靈敏度不高,響應(yīng)恢復(fù)慢,選擇性不好等缺點。這樣,人們從改善材料形貌、摻雜、表面修飾以及材料的復(fù)合等方面改進(jìn)金屬氧化物半導(dǎo)體氣體傳感器性能。本文以提高材料的氣敏性能為出發(fā)點,利用貴金屬對金屬氧化物半導(dǎo)體進(jìn)行表面修飾或者摻雜,并且制備出相應(yīng)的氣體傳感器。利用X射線衍射分析(XRD)、掃描電子顯微鏡(SEM)、透射電子顯微鏡(TEM)以及能量色散X熒光光譜(EDX)等表征手段,來分析材料的組成和形貌。本論文主要包含以下三個部分:第一,通過靜電紡絲方法合成二氧化錫(SnO_2)納米纖維,并利用濕法修飾方法修飾貴金屬金(Au),同時對SnO_2納米纖維材料和Au-SnO_2納米纖維進(jìn)行甲醛氣敏性能測試。其中,相對于SnO_2納米纖維材料,Au-SnO_2材料的響應(yīng)度提高了2倍,而且有較低的工作溫度,以及更好的選擇性。第二,利用靜電紡絲方法制備不同貴金屬銀(Ag)含量摻雜鐵酸鑭(LaFeO_3)納米纖維,對比材料的甲醛氣敏性能,以找出提高氣敏性能的最佳Ag摻雜比。通過貴金屬Ag摻雜之后的LaFeO_3納米纖維材料有著更好的甲醛氣敏特性,其中2 mol%Ag摻雜時,有著最好的氣敏特性。此時,對于100 ppm甲醛氣體有著20的靈敏度,檢測下限可達(dá)5 ppm,響應(yīng)恢復(fù)時間在5 s之內(nèi),而且對甲醛氣體有著很好的選擇性。并解釋了Ag摻雜改善氣敏性能的機(jī)理。第三,通過水熱法來合成SnO_2八面體材料,并在表面修飾貴金屬Au,制備出AuSnO_2八面體材料,通過表征手段證明Au成功的修飾在SnO_2八面體材料表面,并且測試了Au-SnO_2八面體材料的乙炔氣敏性能。純的SnO_2八面體材料區(qū)分乙炔氣體的能力并不好,而利用Au粒子的表面修飾之后,對于乙炔氣體的響應(yīng)度和選擇性明顯提高。Au修飾SnO_2八面體材料對于100 ppm乙炔氣體有著33的響應(yīng),檢測下限可低達(dá)1ppm,而且極大的降低了器件的工作溫度,展現(xiàn)出了良好的乙炔氣敏性能。
[Abstract]:With the development of society and the progress of science and technology, people pay more and more attention to quality of life. It is inevitable to encounter some poisonous, flammable and explosive gases in daily life, which will cause harm to personal and property. At this point, the gas sensor will play a very important role, it can timely detect the gas atmosphere in the environment. Today, researchers are working on high performance, fast response recovery and high selectivity gas sensors. Among many gas sensors, metal oxide semiconductor gas sensor is one of the most important gas sensors. It has the advantages of simple preparation process, low cost and good gas sensitivity. At present, people try different methods to synthesize oxide semiconductor materials. However, the application of pure oxide semiconductors in gas sensors has some shortcomings, such as low sensitivity, slow response recovery, poor selectivity and so on. In this way, the performance of metal oxide semiconductor gas sensor is improved from the aspects of material morphology, doping, surface modification and material recombination. In order to improve the gas sensitivity of the materials, the surface modification or doping of metal oxide semiconductors with precious metals was carried out, and the corresponding gas sensors were prepared. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray fluorescence spectroscopy (EDX) were used to analyze the composition and morphology of the materials. This thesis mainly includes the following three parts: first, the SnO-2) nanofibers were synthesized by electrospinning. The SnO_2 nanofibers and Au-SnO_2 nanofibers were modified by wet modification method, and the formaldehyde gas sensing properties were tested. Compared with SnO_2 nanofiber material, the responsivity of Au-SnO2 is increased by 2 times, and the working temperature is lower and the selectivity is better. Secondly, lanthanum ferrate (LaFeO3) nanofibers doped with different noble metal Ag (Ag) content were prepared by electrospinning method, and the formaldehyde gas sensing properties of the materials were compared to find out the best Ag doping ratio to improve the gas sensitivity. The LaFeO_3 nanofibers doped with noble metal Ag have better formaldehyde gas sensing properties, and the 2 mol%Ag doped LaFeO_3 nanofibers have the best gas sensing properties. At this time, the sensitivity of 100 ppm formaldehyde gas is 20, the detection limit is up to 5 ppm, the response recovery time is less than 5 seconds, and the selectivity of formaldehyde gas is very good. The mechanism of Ag doping to improve gas sensitivity is also explained. Thirdly, the SnO_2 octahedron material was synthesized by hydrothermal method. The AuSnO_2 octahedron material was prepared by modifying the surface of the noble metal Au. the au was successfully modified on the surface of the SnO_2 octahedron material by means of characterization. The acetylene gas sensing properties of Au-SnO_2 octahedral materials were also tested. The ability of pure SnO_2 octahedron material to distinguish acetylene gas is not good, but after surface modification of au particles, the responsivity and selectivity of SnO_2 octahedron modified with au particles to acetylene gas increase obviously, and the SnO_2 octahedron material modified by au has 33 response to 100 ppm acetylene gas. The detection limit can be as low as 1 ppm, and greatly reduces the operating temperature of the device, showing good acetylene gas sensitivity.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TN304;TP212

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本文編號：1922017