石墨烯—介孔金属氧化物复合材料的介观结构调控与气敏性能研究

发布时间：2018-10-26 09:28

【摘要】：气体传感器在工业生产、公共安全、环境监控、医学诊断等领域应用广泛。随着工业技术的迅猛发展和人们安全健康意识的提高,迫切需要发展先进的气体传感技术,而高效气敏材料被视为其中关键。介孔金属氧化物和石墨烯是两类非常有应用潜力的气敏材料,基于二者开发高效的纳米复合气敏材料具有重要意义。复合材料的气敏性质不仅与介孔金属氧化物的介观结构、骨架成份、表面活性相关,也与石墨烯的尺寸、表面功能基团类型与数量及二者的比例、复合方式等有密切联系,本文对此做了相关的研究。采用介孔氧化硅KIT-6为模板,通过纳米浇筑法制备了一系列具有不同介观结构参数的有序介孔氧化铟,研究了 KIT-6孔尺寸、锻烧容器开口程度对氧化铟在KIT-6两套对映异构孔道里限域生长的影响,发现当KIT-6的孔道尺寸较小、煅烧容器开口程度较高时,氧化铟倾向于在其中一套孔道里生长,产生薄孔壁(5 nm)、大孔尺寸(12 nm)的有序介孔氧化铟;当KIT-6两套对映异构的孔道尺寸较大时,氧化铟倾向于同时在其两套孔道里生长,产生厚孔壁(9 nm)、小孔尺寸(4nm)的有序介孔氧化铟。薄孔壁、大孔尺寸的有序介孔氧化铟在甲醛气敏性能测试中表现出高的敏感度(对9 ppm甲醛气体敏感度可达324),显著优于厚孔壁、小孔尺寸的有序介孔氧化铟。采用超声辅助混合组装及溶剂热还原,制备了一系列介孔氧化铟-石墨烯复合材料,发现石墨烯还原程度较高、其加入量为0.01%时,复合材料对对乙醇气体具有较高敏感度和选择性。另外,基于薄孔壁、大孔尺寸介孔氧化铟的复合材料对乙醇气体的敏感度比基于厚孔壁、小孔尺寸介孔氧化铟的复合材料更高。采用溶胶凝胶法制备了大孔尺寸(29 nm)的介孔铁酸镧以及石墨烯-介孔铁酸镧复合材料,发现石墨烯的加入显著改善了其对甲醛气体的敏感性能。
[Abstract]:Gas sensors are widely used in industrial production, public safety, environmental monitoring, medical diagnosis and other fields. With the rapid development of industrial technology and the improvement of people's awareness of safety and health, it is urgent to develop advanced gas sensing technology, and high efficiency gas sensing materials are regarded as the key among them. Mesoporous metal oxides and graphene are two kinds of gas sensing materials with great potential for application. It is of great significance to develop high efficiency nanocomposite gas sensing materials based on them. The gas-sensing properties of the composites are not only related to the mesoporous metal oxide mesoscopic structure, skeleton composition, surface activity, but also closely related to the size of graphene, the type and quantity of surface functional groups, the ratio of them, and the recombination mode. This article has done the related research to this. A series of ordered mesoporous indium oxide (indium oxide) with different mesoporous structure parameters were prepared by nano-pouring method using mesoporous silica KIT-6 as template. The pore size of KIT-6 was studied. The effect of the opening degree of calcined vessel on the growth of indium oxide in two sets of diisomeric channels of KIT-6 shows that when the pore size of KIT-6 is smaller and the opening degree of calcined vessel is higher, indium oxide tends to grow in one of the channels. The ordered mesoporous indium oxide with thin pore wall (5 nm), macropore size (12 nm) was produced. When the diisomerism pore size of KIT-6 is larger, indium oxide tends to grow in two channels at the same time to produce ordered mesoporous indium oxide (4nm) with thick pore wall (9 nm), pore size). The ordered mesoporous indium oxide with thin and large pore size shows a high sensitivity in formaldehyde gas sensing test (the sensitivity of 9 ppm formaldehyde gas is up to 324), which is significantly better than that of ordered mesoporous indium oxide with thick pore wall and small pore size. A series of indium oxide graphene mesoporous composites were prepared by ultrasonic assisted mixing assembly and solvothermal reduction. The composite has high sensitivity and selectivity to ethanol gas. In addition, the sensitivity of the composite based on thin pore wall and mesoporous indium oxide with large pore size to ethanol gas is higher than that based on thick pore wall and small pore size indium oxide composite. Macroporous lanthanum ferrate (29 nm) and graphene mesoporous lanthanum ferrate composites were prepared by sol-gel method. It was found that the addition of graphene significantly improved the sensitivity of lanthanum mesoporous ferrate to formaldehyde gas.
【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB332

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