共查询到18条相似文献,搜索用时 46 毫秒
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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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金属氧化物半导体气敏传感器的研究和开发进展 总被引:13,自引:0,他引:13
综述了近期国内外金属氧化物半导体气敏传感器的研究和开发进展;阐述了半导体气敏材料的气敏作用及机理;展望了今后半导体气敏传感器技术的发展趋向。 相似文献
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以间苯二酚和甲醛为前驱体,原位合成的Mg(OH)2为模板剂,KOH作为催化剂、沉淀剂、活化剂,一步法合成具有小/中/大孔的分级多孔炭。使用扫描电镜、透射电镜、氮气吸附、X射线衍射对样品的结构进行表征。通过恒流充放电、循环伏安、电化学阻抗谱,测试样品在1mol/L的(C2H5)4NBF4/碳酸丙烯酯(Propylene carbonatePC)电解液中的电化学性能。结果表明,随着KOH对间苯二酚用量的增加,材料的比表面积和孔容先增大后减小,其最大值分别为1300m2/g和0.89cm3/g。该材料具有良好的容量性能和功率性能,在电流密度0.1A/g时,最高质量比电容可以达到116F/g;当电流密度增大到5A/g时,电容保持率为78%。 相似文献
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气体传感器的研究与发展 总被引:1,自引:0,他引:1
叙述了国内外气体传感器的研究与开发情况。尤其是对SnO2气体传感器的研究现状做了综合性阐述,并且介绍了其它类型的气体传感器的开发现状。 相似文献
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1 INTRODUCTION The prediction of gas diffusion in porous media is critical for the design and analysis of membrane- and solid-catalyzed reaction processes. It is evident that many physical and physicochemical processes within porous media are significantly influenced by the porous structure[1-6]. For over two decades, frac- tal geometry has been applied to describe the irregular morphology of natural and artificial objects, and the tortuous degree of diffusion and adsorption or diffu- sion… 相似文献
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PTFE多孔膜气体渗透数学模型和膜孔结构的影响 总被引:1,自引:0,他引:1
Membrane-based separation processes are new technology combined membrane separation with conventional separation. Hydrophobic porous membranes are often used in these processes. The structure of hydrophobic porous membrane has significant effect on mass transfer process. The permeabilities of five kinds of gas, He, N2,O2, CO2 and water vapor, across six polytetrafluoroethylene(PTFE) fiat membranes were tested experimentally.Results indicated that the greater the membrane mean pore size and the wider the pore size distribution are, the higher the gas permeability. A gas permeation model, including the effects of membrane structure parameter and gas properties, was established. A comprehensive characteristic parameter (including porosity, thickness and tortuosity) was found more effective to express the influence of membrane structure in gas permeation process. The predicted permeation coefficients were in good agreement with experimental data. 相似文献
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以金属有机骨架(MOFs)MIL-53(Fe)为模板,合成了一种多孔金属氧化物Fe Ox。这种材料保留了MOFs的多孔性和高比表面积(934 m2/g),还具有一定的磁性(35.10 emu/g)和耐酸碱性,使其具备了在恶劣环境下催化氧化降解有机染料的性能。在H2O2和NH2OH存在的条件下降解亚甲蓝的实验结果表明,在pH=3.0,NH2OH浓度为10mmol/L,H2O2浓度为10 mmol/L的条件下,降解性能最优,与其他材料相比,表现出了较高的催化性能。 相似文献
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基于纤蛇纹石一维纳米管结构和形态属性,以石棉尾矿中纤蛇纹石短纤维为原料,采用酸浸法去金属氧化物,获得纤维状多孔SiO2,并对不同去金属氧化物作用阶段产物的形貌、物相组成和谱学特征进行表征。结果表明,去金属氧化物作用(以MgO浸取率表征)优化的工艺条件为:硫酸溶液质量分数35%,反应温度90℃,反应时间2.00h,液固比10∶1。纤蛇纹石结构中的金属氧化物组分被去除后,仅保留具有石棉纤维形态的非晶态SiO2。在纤蛇纹石去金属氧化物作用过程中,氢氧镁石八面体片结构组元被去除的同时,原位保留和修饰了硅氧四面体片结构组元,形成了纤维状多孔SiO2。 相似文献
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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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课题采用离心甩丝法制备了聚乙烯吡咯烷酮(PVP)与乙酸锌纤维前驱体,然后通过煅烧前驱体成功制备了多孔ZnO纤维。采用XRD、TG、IR、SEM等方法对制备的前驱体和多孔ZnO纤维结构进行了表征。 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
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Defect engineering in semiconducting oxides: Control of ZnO surface potential via temperature and oxygen pressure
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The technological usefulness of a semiconductor often depends on the types, concentrations, charges, spatial distributions, and mobilities of the atomic‐scale defects it contains. For semiconducting metal oxides, defect engineering is relatively new and involves complex transport and reaction networks. Surface‐based methods hold special promise in nanostructures where surface‐to‐volume ratios are high. This work uses photoreflectance augmented by X‐ray photoelectron spectroscopy to show that the surface potential VS for Zn‐terminated ZnO(0001) can be manipulated over a significant range 54.97–79.08 kJ/mol (0.57–0.82 eV) via temperature and the partial pressure of O2. A defect transport model implies this variation in VS should affect the injection rate of oxygen interstitials by a factor of three. Such injection plays an important role in controlling the concentrations of oxygen vacancies deep in the bulk, which often prove troublesome as trapping centers in photocatalysis and photovoltaics and as parasitic emitters in light‐emitting devices. © 2015 American Institute of Chemical Engineers AIChE J, 62: 500–507, 2016 相似文献
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Irina Kononova Pavel Kononov Vyacheslav Moshnikov Sergey Ignatev 《International journal of molecular sciences》2021,22(19)
It was developed a new technique to assess micro- and mesopores with sizes below a few nanometers. The porous materials with hierarchical fractal-percolation structure were obtained with the sol-gel method. The tetraethoxysilane hydrolysis and polycondensation reactions were performed in the presence of salts as the sources of metal oxides. The porous materials were obtained under spinodal decomposition conditions during application of the polymer sol to the substrate surface and thermal treatment of the structures. The model is based on an enhanced Kepler net of the 4612 type with hexagonal cells filled with a quasi-two-dimensional projection of the Jullien fractal after the 2nd iteration. The materials obtained with the sol-gel method were studied using the atomic force microscopy, electron microscopy, thermal desorption, as well as an AutoCAD 2022 computer simulation of the percolation transition in a two-component system using the proposed multimodal model. Based on the results obtained, a new method was suggested to assess micro- and mesopores with sizes below a few nanometrs, which cannot be analyzed using the atomic force microscopy and electron microscopy. 相似文献