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1.
三氧化钨(WO_3)因其氧含量与氧缺陷随着环境因素变化而变化,使得其成为一种理想的二氧化氮(NO_2)气敏材料。简要介绍了WO_3材料的结构、特性和NO_2气敏机理,综述了近5年来高性能WO_3气敏材料在NO_2气体检测中的最新研究进展,分析了WO_3气敏材料存在的主要问题与挑战,重点讨论高比表面积WO_3材料、WO_3复合材料等的解决途径。最后,展望了WO_3气敏材料在NO_2气敏传感器中的发展方向和应用前景,提出了开发低电阻WO_3膜电极是未来高性能NO_2传感器的研究重点。  相似文献   

2.
半导体基纳米复合材料光催化研究进展   总被引:19,自引:0,他引:19  
综述了半导体多相光催化的基本原理、半导体基纳米复合材料的基本结构、制备方法及复合材料在光电化学方面对材料性能的影响.着重强调了半导体基纳米复合材料与单一的半导体材料相比光催化性能的提高,并对半导体基纳米复合材料在光催化领域的研究和应用提出了一些展望.  相似文献   

3.
通过微波辅助溶剂热法一锅制备了贵金属Pt修饰的WO_3(Pt/WO_3),并将该材料应用于呼吸生物标志物丙酮的检测。实验结果表明,相比于纯相WO_3,贵金属Pt修饰的WO_3明显提高了材料对于丙酮气体的响应的灵敏度,并且当反应溶液中加入0.25 mL 0.1 mol/L的氯铂酸乙醇溶液时得到的材料(Pt/WO_3-2)对丙酮的气敏性能提高最为明显,提高了23倍。Pt/WO_3-2对丙酮检测的下限低至250 ppb。Pt/WO_3-2表现出对丙酮气体的良好的选择性和长期稳定性。本实验采用的微波辅助溶剂热法一锅制备贵金属修饰的氧化物的方法,为后续构筑高性能传感器提供了一种新的思路。  相似文献   

4.
WO_3基纳米材料具有光催化降解、光解水、电致变色、热致变色和光致变色等特性,在光催化剂、新能源利用、智能窗口、传感器和平板显示器等领域有广阔的应用前景。详细介绍了喷雾干燥法、溶胶-凝胶法、水热法和模板法在制备WO_3基纳米材料方面的研究进展,同时分析了各制备方法目前所存在的问题。综述了WO_3基纳米材料近年来在催化降解、污染物吸附、光解水制氢、电致变色等方面应用的研究现状,分析了其未来的应用和发展前景。  相似文献   

5.
迈向微型化、集成化及具有高选择性和灵敏度的固体电解质气体传感器已成为未来的发展趋势。文章采用磁控溅射法成功制备了WO_(3)气体传感器敏感电极材料,并通过X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)等表征手段研究了WO_(3)的结构、成分和形貌并测试了该气体传感器对NO_(2)的气敏性能。XRD结果表明,当退火温度大于400℃时,WO_(3)出现(200)衍射峰,且该衍射峰随退火温度增加而显著增强,表明WO_(3)结晶质量增加。SEM测试结果表明,随着退火温度的升高,薄膜的晶粒尺寸逐渐增大。当退火温度达到500℃时,采用谢乐公式计算其晶粒尺寸达到23 nm。EDS结果表明,退火温度对薄膜的成分也有较大影响,O:W原子比例呈现增大趋势,由2.7增加到3.2,这与XPS结果相符合。通过高温气敏性能测试表明,所制得的WO_(3)敏感电极对NO_(2)表现出了明显的气体响应。本研究为制备微型化、高选择性和灵敏性的固体电解质气体传感器提供了一定的研究基础。  相似文献   

6.
新型高性能氢气传感器   总被引:2,自引:0,他引:2  
肖定全  余萍 《功能材料》1998,29(3):268-270
报道了本项目组发明的Al2O3基新型高性能半导体陶瓷气体传感器材料及用以制造氢气体传感器的研究结果。这类新型气体传感器具有工作温度低、气体选择性好、检测灵敏度与气体浓度呈近似线性关系、响应时间和恢复时间快、抗湿性能好等明显优点,可望进行工业规模的生产。  相似文献   

7.
NH3的排放对环境和人类健康有重大影响。近年来,对NH3的高效实时检测已成为环境监测及分析化学领域的研究热点。作为二维(2D)纳米材料的典型代表——石墨烯,以其独特的物化性能为气体的检测提供了良好的平台。石墨烯及石墨烯基复合材料已被广泛应用于NH3气体的检测。本文综述了近10年来国内外基于石墨烯基复合材料的NH3气体传感器的研究进展,重点介绍了几种常见石墨烯复合材料在NH3气体传感器中的应用。与本征石墨烯相比,金属粒子掺杂石墨烯可增强其对NH3的吸附能力;金属氧化物掺杂石墨烯可有效提高NH3气体传感的灵敏度,但响应时间长、重复性较差;有机高分子掺杂石墨烯稳定性相对较差,对环境要求较高;石墨烯三元复合材料可有效提高传感器的稳定性,改善传感选择性。最后,文章对NH3气体传感器的未来发展趋势进行了展望。  相似文献   

8.
本文以几种半导体传感器为例简要叙述了半导体功能材料的发展动向。其中包括气体传感器材料、半导体磁敏功能材料、半导体光传感器材料和半导体压敏功能材料等的进展情况及发展趋势.  相似文献   

9.
硅藻是由具有独特纳米和微米形态的单细胞藻类产生的三维(3D)天然生物材料,具有众多优异的结构。硅藻纳米技术是近年来出现的一个新的研究领域,它在生物学、传感器、吸附、纳米输送、新能源等诸多领域中得到了研究及应用。由于它特殊的多孔三维分层结构、高的比表面积以及与其他导体或半导体材料结合与转换的能力,在能量存储、低成本天然电极材料、具有强吸附性和优异的热稳定性的储氢材料以及热储能材料中得到了广泛应用。根据近年来国内外研究现状,展示了硅藻基复合材料在超级电容器、电池、太阳能电池等能源设备上应用的情况,以及硅藻基复合材料在储氢、储热等储能设备上的应用,并根据这些基本情况指出未来硅藻基复合材料的发展趋势。  相似文献   

10.
气体传感器在现代科学技术领域发挥着重要作用,它们被广泛用于公共安全、污染监测、呼吸分析、智能家居等。由于其低成本、高灵敏度、易制造的优势,促使众多研究人员对气体传感器展开广泛研究。尤其是金属氧化物半导体(MOS)型气体传感器,此类传感器可检测150多种有毒有害气体,对具有易挥发、易燃易爆性质的乙醇(C2H5OH)有机挥发性气体(VOCs)具有良好的气敏特性。本文回顾了近一年来最先进的MOS电阻型乙醇传感器,详细阐述了传感器对乙醇气体的传感机制;重点介绍了不同MOS型传感器对乙醇的敏感特性,分析了诸如金属掺杂、异质结复合材料以及MOS分等级结构对乙醇传感器性能的影响。通过分析可得,SnO2、ZnO基传感器对乙醇的传感性能最佳,特别是经金属掺杂和由不同导电类型半导体构建的异质结MOS传感器。  相似文献   

11.
The gas which may be lethal to human body with short-term exposure in common industrial fields or workplaces in LAB may paralyze the olfactory sense and impose severe damages to central nervous system and lung. This study is concerned with the gas sensor which allows individuals to avoid the toxic gas that may be generated in the space with residues of organic wastes under 50 degrees C or above. This study investigates response and selectivity of the sensor to hydrogen sulfide gas with operating temperatures and catalysts. The thick-film semiconductor sensor for hydrogen sulfide gas detection was fabricated WO3/SnO2 prepared by sol-gel and precipitation methods. The nanosized SnO2 powder mixed with the various metal oxides (WO3, TiO2, and ZnO) and doped with transition metals (Au, Ru, Pd Ag and In). Particle sizes, specific surface areas and phases of sensor materials were investigated by SEM, BET and XRD analyses. The metal-WO3/SnO2 thick films were prepared by screen-printing method. The measured response to hydrogen sulfide gas is defined as the ratio (Ra/R,) of the resistance of WO3ISnO2 film in air to the resistance of WO3/SnO2 film in a hydrogen sulfide gas. It was shown that the highest response and selectivity of the sensor for hydrogen sulfide by doping with 1 wt% Ru and 10 wt% WO3 to SnO2 at the optimum operating temperature of 200 degrees C.  相似文献   

12.
Interest in detecting and determining concentrations of toxic and flammable gases has constantly been on the increase in recent years due to increase of modernization, industrialization and high standards of life. Detection of such gases is very important in many different fields such as industrial emission control, household and social security, vehicle emission control and environmental monitoring. Metal oxide gas sensors are among most important devices to detect a large variety of gases. α-Fe2O3, an environmental friendly semiconductor (E g = 2.1 eV), is the most stable iron oxide under ambient atmosphere and because of its low cost, high stability, high resistance to corrosion, and its environmentally friendly properties is one of the most important metal oxides for gas sensing applications. This is the first review about gas sensing properties of α-Fe2O3 nanostructures. In this paper gas sensing properties of α-Fe2O3 are extensively reviewed. After a brief explanation about metal oxide gas sensors and α-Fe2O3, sensors based on α-Fe2O3 nanomaterials have been reviewed. Gas sensing section is divided into five subsections: pure α-Fe2O3 gas sensors, metal/α-Fe2O3 gas sensors, metal oxide/α-Fe2O3 gas sensors, polymer/α-Fe2O3 gas sensors and graphene/α-Fe2O3 gas sensors.  相似文献   

13.
为降低WO3气敏元件的工作电压,改善WO3基敏感材料的气敏性能,采用化学吸附沉淀-水热法合成WO3和WO3/SWCNT复合材料,并研究矿化剂用量和SWCNT掺杂量对其气敏性能的影响.结果表明,大剂量矿化剂的使用会降低WO3的气敏性能;碳纳米管掺杂可以使WO3在较低的工作温度下有较高的灵敏度.SWCNT掺杂量为1%的元件...  相似文献   

14.
利用霍耳效应成功地研制了WO3半导体气敏传感器.这种新型传感器不仅可以根据需要输出几毫伏至几十毫伏甚至几百毫伏的直流电压,而且具有其它半导体传感器所没有的优点--无需另外加热.在实验中对NO2气体进行检测,结果表明:传感器的输出霍耳电动势在几毫伏到几百毫伏之间,且随待测气体浓度变化而变化.因此,利用霍耳效应制作气敏传感器是一条完全可行的新思路.  相似文献   

15.
Organic semiconductor gas sensor is one of the promising candidates of room temperature operated gas sensors with high selectivity. However, for a long time the performance of organic semiconductor sensors, especially for the detection of oxidizing gases, is far behind that of the traditional metal oxide gas sensors. Although intensive attempts have been made to address the problem, the performance and the understanding of the sensing mechanism are still far from sufficient. Herein, an ultrasensitive organic semiconductor NO2 sensor based on 6,13‐bis(triisopropylsilylethynyl)­pentacene (TIPS‐petacene) is reported. The device achieves a sensitivity over 1000%/ppm and fast response/recovery, together with a low limit of detection (LOD) of 20 ppb, all of which reach the level of metal oxide sensors. After a comprehensive analysis on the morphology and electrical properties of the organic films, it is revealed that the ultrahigh performance is largely related to the film charge transport ability, which was less concerned in the studies previously. And the combination of efficient charge transport and low original charge carrier concentration is demonstrated to be an effective access to obtain high performance organic semiconductor gas sensors.  相似文献   

16.
This paper gives a statistical view about important contributions and advances on semiconductor metal oxide (SMO) compounds based gas sensors developed to detect the air pollutants such as liquefied petroleum gas (LPG), H2S, NH3, CO2, acetone, ethanol, other volatile compounds and hazardous gases. Moreover, it is revealed that the alloy/composite made up of SMO gas sensors show better gas response than their counterpart single component gas sensors, i.e., they are found to enhance the 4S characteristics namely speed, sensitivity, selectivity and stability. Improvement of such types of sensors used for detection of various air pollutants, which are reported in last two decades, is highlighted herein.  相似文献   

17.
This review paper discusses the influence of morphology and crystallographic structure on gas-sensing characteristics of metal oxide conductometric-type sensors. The effects of parameters such as film thickness, grain size, agglomeration, porosity, faceting, grain network, surface geometry, and film texture on the main analytical characteristics (absolute magnitude and selectivity of sensor response (S), response time (τres), recovery time (τrec), and temporal stability) of the gas sensor have been analyzed. A comparison of standard polycrystalline sensors and sensors based on one-dimension structures was conducted. It was concluded that the structural parameters of metal oxides are important factors for controlling response parameters of resistive type gas sensors. For example, it was shown that the decrease of thickness, grain size and degree of texture is the best way to decrease time constants of metal oxide sensors. However, it was concluded that there is not universal decision for simultaneous optimization all gas-sensing characteristics. We have to search for a compromise between various engineering approaches because adjusting one design feature may improve one performance metric but considerably degrade another.  相似文献   

18.
J. Mizsei 《Thin solid films》2007,515(23):8310-8315
The porous silicone (PSi) is a relatively new and promising semiconductor material with special physical and chemical properties which somewhat differ from the properties of single crystal Si. Some of these properties are valuable in the field of gas sensor technology, but a lot of questions arise in connection with its application. Do we really need porous semiconductor material for proper gas sensing function? How can electrical properties of the PSi layer be measured if the electrical contacting is problematic? Is it possible to activate the PSi with catalytic noble metal layers or particles? What about the Fermi-level pinning in the PSi layer? The main target of this article is to seek answers to questions listed above and to give a short, but still comprehensive review of the application of the PSi layers on the field of the gas sensor technology, with special care on electrical output signal giving sensors.  相似文献   

19.
采用H2O2氧化-水热结晶法制备掺杂La(NO3)3(La(NO3)3与WO3的摩尔比为1%、3%、5%、7%、9%)的WO3粉体,测试了不同比例掺杂La所得元件的气敏性能,得出结论:掺杂量为5%的时候气敏性能最佳。采用同样的方法制得掺杂量为5%La、Ce、md、Sm、Eu和Gd的WO。气敏元件,并测试了其气敏性能,掺杂5%Gd的WO3气敏元件相比其他稀土金属元素掺杂的WO3气敏元件对50ppmNO2和Cl2的灵敏度是最好的,分别为305.667和416.233。  相似文献   

20.
The continuous evolution of nanotechnology in these years led to the production of quasi-one dimensional (Q1D) structures in a variety of morphologies such as nanowires, core-shell nanowires, nanotubes, nanobelts, hierarchical structures, nanorods, nanorings. In particular, metal oxides (MOX) are attracting an increasing interest for both fundamental and applied science. MOX Q1D are crystalline structures with well-defined chemical composition, surface terminations, free from dislocation and other extended defects. In addition, nanowires may exhibit physical properties which are significantly different from their coarse-grained polycrystalline counterpart because of their nanosized dimensions. Surface effects dominate due to the increase of their specific surface, which leads to the enhancement of the surface related properties, such as catalytic activity or surface adsorption: key properties for superior chemical sensors production.High degree of crystallinity and atomic sharp terminations make nanowires very promising for the development of a new generation of gas sensors reducing instabilities, typical in polycrystalline systems, associated with grain coalescence and drift in electrical properties. These sensitive nanocrystals may be used as resistors, and in FET based or optical based gas sensors.This article presents an up-to-date review of Q1D metal oxide materials research for gas sensors application, due to the great research effort in the field it could not cover all the interesting works reported, the ones that, according to the authors, are going to contribute to this field’s further development were selected and described.  相似文献   

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