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金属氧化物型半导体气体传感器是目前常用的乙醇检测手段,深入研究和改进金属氧化物型半导体材料是提升传感器性能的重要方式。本文首先论述了气敏检测的机理和影响因素,并综述了近年来发展的主要金属氧化物型半导体气敏材料,重点介绍了不同微观结构的Co3O4、ZnO、SnO2及掺杂金属氧化物材料、氧化物异质结等的研究和发展情况,对它们的合成方法、结构特点以及结构与乙醇气敏性能之间的关系进行了探讨。分析表明,减小材料颗粒尺寸、构建大比表面积多孔结构、掺杂和复合改性,是提升金属氧化物材料气敏性能的有效措施。此外,基于传感器微小化的趋势,以微机电系统(MEMS)工艺为基础的微型传感器成为气体传感器的发展趋势。然而,目前针对金属氧化物气敏材料的制备依然缺乏一定的理论指导,气体检测缺乏相应的机理研究,亟需物理、化学、材料等多学科的相互结合,促进乙醇等半导体气体传感器的进一步发展。 相似文献
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三乙胺是一种应用广泛但对人体有毒副作用的挥发性有机物,需要长期有效的监测,开发一种性能稳定、安全可靠的三乙胺气敏传感器,实现对环境中三乙胺气体浓度实时检测,对于三乙胺的安全储存、运输和使用等环节是至关重要的。金属氧化物半导体基气敏传感器具有制备简单、价格低廉、响应值高等优点,在三乙胺气体的检测中具有不可替代的作用。重点介绍了基于金属氧化物半导体的三乙胺传感器最新研究进展。综述了近年来包括掺杂、异质结、有机金属骨架和氧化还原石墨烯在内的关于金属氧化物半导体基三乙胺气敏材料的制备和性能等方面的研究成果。论述了金属氧化物半导体基复合材料对三乙胺气敏性能的机理。展望了金属氧化物基三乙胺气敏材料的未来研究方向。 相似文献
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半导体金属氧化物是一种常见的气敏材料,以该类型材料作为敏感材料可以设计出具有不同传感原理的气体传感器,但选择性和灵敏度不佳却一直是该类气体传感器的不足。为了解决该问题,常将气敏材料与沸石进行复合,制备金属氧化物/沸石气体传感器,利用沸石独特的物理、化学特性来改善金属氧化物的气敏特性。近年来,许多研究者对金属氧化物/沸石气体传感器进行了研究,使该类传感器对目标气体的选择性与灵敏度均有了提升。为了更好地总结已有的研究内容,以气体传感器的检测原理为主线,对金属氧化物/沸石气体传感器进行了总结,结合沸石对气敏特性的改善进行归纳梳理,从传感器的制备方法、气敏特性和敏感机理等多方面进行了详细的整理和分析,为后续此类工作的开展提供基础。 相似文献
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SnO2气敏传感器具有元件制作简单、使用寿命长、稳定性好、对气体的响应时间短等优点,已成为一个重要的研究课题.气敏反应是气体与材料表面接触后发生的化学反应,因此材料的表面组成、掺杂改性、缺陷分布、比表面积等都会影响材料的气敏性能.本文综述了近年来SnO2气敏材料的不同制备方法,以及金属氧化物和贵金属掺杂的SnO2气敏材... 相似文献
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气敏传感器是利用材料的气敏特性实现目标气体浓度检测的电子元器件,在生产安全、环境监测、临床医学等领域均有广泛应用。气敏材料主要分为金属氧化物半导体材料、导电聚合物(CP)材料、金属有机框架材料。导电聚合物因其成本低、易于合成,在室温下对氨气等有害气体表现出良好的响应的特点而受到广泛关注。近年来导电聚合物复合物的研究也极大地提高了导电聚合物的气敏性能。分析了导电聚合物电阻调控机理,重点介绍了近年来对氨气、二氧化氮、硫化氢等气体的导电聚合物及其复合物的气敏传感器的研究进展,简要介绍了导电高分子在甲醇、三乙胺、一氧化碳等气体检测中的研究情况,最后展望了导电聚合物在气体传感领域的应用前景。 相似文献
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《Ceramics International》2016,42(8):9851-9857
Because of their potential applications in gas sensing and catalysis, reduced graphene oxide (RGO) and ZnO have been the focus of much recent attention. However, few reported materials have been produced via the combination of hierarchical ZnO structures with RGO to achieve high sensing performances. In this paper, a hydrothermal method was used to synthesize hierarchical porous ZnO nanoflowers, which were then combined with graphene to enhance their sensing performances. The rapid detection of 1 ppm NO2 was achieved at 174 °C. The morphologies and structures of these materials were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. Photoluminescence measurements and X-ray photoelectron spectroscopy were also used to investigate the mechanism of gas sensing by these materials. 相似文献
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Shao-Xia Zhang Long Xu Zhi-Hui Chen Shu-Ting Fan Zhen-Jiang Qiu Zi-Jun Nie Bang-Jing Li Sheng Zhang 《应用聚合物科学杂志》2021,138(34):50849
γ-cyclodextrin (CD)-metal-organic framework (MOF)-K is developed as a new kind of green template for the preparation of hierarchical porous carbon (HPC). Three-level porous structure (micro-, meso-, and macro-pores) has been successful constructed by calcined γ-CD-MOF-K at 600°C. The fabricated carbon (HPC-600) shows good microwave adsorption ability due to its unique hierarchical porous structure (macropores allow microwave enter the interior of the absorbents, and then micro- and meso-pores attenuate the incident microwave effectively by multiple reflections and polarization loss caused.) The minimum reflection loss (RL) is − 23.5 dB and the effective absorption bandwidth (EAB, RL≤− 10 dB) is 4.3 GHz. This work provides a good reference for efficient and environment-friendly microwave absorbents. In addition, the applications of HPC-600 may further expand to adsorption, sensing and supercapacitors due to the hierarchically porous structure. 相似文献
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Many recent efforts are directed toward developing high-performance gas sensors based on metal oxide nanostructures operating at room temperature, as it lowers the power consumption, simplifies the device fabrication as well as improves the safety and stability of the sensors. The light-activated gas sensing technology was intensively studied because of its high effectiveness in improving the gas sensing performance of metal oxide nanostrctures at room temperature. This review is covers comprehensive advances in the emerging and feasible approaches for improving nanostructured metal oxide-based gas sensors by light activation, especially the progresses made in the last five years. We first summarize the effects of light-activation on gas sensing behavior of metal oxide nanostructures with some new insights into the related mechanisms. For enhancing the light-activated gas-sensing performance some possible strategies are then introduced, which include the modification of the size, dimension, nanoarchitecture, porous or hierarchical structure and doping or defect engineering, as well as the construction of nanocomposite sensing materials. Finally, some recent developments in light source and device structure design towards low power gas sensor systems are discussed. We hope that this review would provide some useful information to the design of light-activated metal oxide gas sensors operating at room temperature. 相似文献
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Niina Merilaita Teemu Vastamäki Arnold Ismailov Erkki Levänen Matti Järveläinen 《Ceramics International》2021,47(8):10742-10748
Hierarchically porous structures are important in adsorption applications and can be used in gas treatment. Hierarchy in adsorbents offers flow channels on different scales, resulting in fast gas flow into a structure. Additive manufacturing, a technology capable of forming intricate geometries, was seen as a potential method to form porous adsorption structures. Stereolithography was chosen as the fabrication method for hierarchically porous zeolite structures because of its high resolution and superior forming capability. The focus of this study was on tailoring the properties of light-cured resin to maximize stability during shaping and shape retention in the debinding stage. Successful slurry preparation was required for demonstrating that monoliths with channel geometry and retained adsorption properties can be manufactured with stereolithography. The final printed structures exhibited hierarchical porosity consisting of flow channels, macropores between the primary particles and the characteristic microporosity of zeolite framework. The structure was manufactured by using blue light to cure layers of resin containing ZSM-5 zeolite. An appropriate debinding heat-treatment cycle was generated based on the TGA and DSC thermal analysis results. The properties of the porous structure were analysed by comparing the BET surface area, XRD patterns and SEM images of as-received powder and a debound piece. The measured BET adsorption properties of the final monoliths remained comparable to the as-received ZSM-5 powder. Based on this study, stereolithography can be utilized to manufacture porous zeolite structures. 相似文献
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Ying Wang Xiaodong Wang Guiyun Yi Yawei Xu Lixing Zhou Ying Wei 《Journal of Porous Materials》2016,23(6):1459-1466
Layered hierarchical porous SnO2 (LHP-SnO2) have been synthesized by a two-step method, in which pure SnO2 nanoparticles(NPs) with the diameter about 3.2 nm were prepared firstly through a hydro-thermal method, and then LHP-SnO2 were prepared by utilizing polystyrene (PS) microspheres as a template and SnO2 NPs as a precursor. The as-prepared sample consisted of porous SnO2 layers, in which each layer presents a three-dimensional random arrangement of macropores with average pore diameter of about 260 nm. The Nitrogen adsorption–desorption analysis implied that the sample was characterized with large surface area of 140.67 m2/g and extensive micropores and mesopores structure. Compared with pure SnO2 NPs, the LHP-SnO2 exhibited an obvious improvement in gas sensing properties. These results indicate that the layered hierarchical porous structure possess potential application in sensing materials. 相似文献
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分级多孔炭因其高比表面积、大孔容及分级孔结构,目前广泛应用于超级电容器、锂离子电池、催化及吸附等领域。废弃物在热解气化过程中残留的碳基材料则是制备分级多孔炭很好的前体。本文根据废弃物来源及自身特性间的差异,对生物质和非生物质废弃物作为原料制备的分级多孔炭的特性及应用进行了综述及总结。并对不同制备方法的优劣及适用对象进行了比较。对分级多孔炭在挥发性有机物(VOCs)吸附、CO2吸附捕集、染料吸附、抗生素以及酚类物质的吸附过程进行分析,总结出废弃物基多孔炭在孔径结构及表面杂原子掺杂情况下的优势能够增强这几类物质的吸附效果。结合已有文献,对废弃物基分级多孔炭的制备、孔径设计及表面官能团设计提出展望。 相似文献
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共价有机框架(covalent organic frameworks,COFs)是一类通过共价键连接有机构筑单元设计组装而成的具有周期性二维(2D)或三维(3D)网状结构的多孔有机聚合物,具有高比表面积、低密度、高度有序的周期性结构和易于功能化等特点。与单一孔COFs相比,多级孔COFs具有分级的孔道结构、不同的孔环境、极易接近的活性位、优异的传质和扩散性能,在气体分离和储存、环境治理、光电、生物医药、催化等领域具有更为广阔的应用前景。但由于多级孔COFs合成条件苛刻,其结构多样性仍然十分有限。本文从反应类型、设计策略、合成方法、功能化修饰、应用领域等方面系统地综述了多级孔COFs的研究进展,提出开发更多的单体、键合类型、拓扑结构,拓展更多的修饰手段,充分发挥多级孔结构优势的发展趋势。未来通过不断探索与研究,一定能开发出更多具有新的拓扑结构、不断提高的性能及更多新的应用的多级孔COFs材料,实现多级孔COFs快速、高效、低成本的加工成型,使其在能源、生物、环境、催化等领域发挥出不可替代的作用。 相似文献
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Kyusung Kim Pil gyu Choi Toshio Itoh Yoshitake Masuda 《International Journal of Applied Ceramic Technology》2023,20(2):959-965
Atomic defects can enhance catalytic efficiency by providing coordinatively unsaturated sites in the crystal structure of metal oxides. It allows facile chemical reactions because the sites can react with other molecules with relatively lower energy. Therefore, atomic defect engineering can be a cost-effective strategy to replace novel metal catalysts for the development of ultrasensitive gas sensors. Herein, we fabricated porous ZnO nanobelts with atomic step structures for acetone, ethanol, and isoprene gas sensing under the parts-per-billion (ppb) level. Numerous atomic step structures could be formed by removing H and F atoms during the conversion process of ZnOHF at 500°C. The synthesis method of metal oxide nanomaterial by conversion from metal hydroxide fluoride will provide the atomic defects and it will be useful to prepare ultrasensitive sensing material. Furthermore, the gas selectivity of the porous ZnO nanobelt was investigated based on the appearance energy associated with the separation of the methyl group. 相似文献
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超级电容器因其高功率密度、超高速充放电、高稳定性等突出特点在电化学储能装置中引起人们极大关注.在当前开发的电极材料中,碳材料因其良好的导电性、孔隙率及形貌可调等特点备受青睐.传统的单一微孔碳材料具有较大的比表面积,但存在利用率低、孔道堵塞、电阻较大等问题.针对上述问题,研究人员对分级结构多孔碳材料开展了广泛的研究.本工... 相似文献