SnO2纳米棒的制备及表征

由 SnCl4, NaBH4 和 NaCl、KCl 或 KCl NaCl组成的3种微乳液混合发生反应制备SnO2 前驱物,在熔盐环境中再经 710、760、785 和 900℃等温度焙烧 15min、1h、2h、3h,成功地制备了金红石结构的SnO2 纳米棒,并用透射电子显微镜, X 射线衍射对SnO2 纳米棒的结构进行了表征。讨论了焙烧温度、焙烧时间和熔盐对 SnO2 纳米棒的影响,用熔盐合成机理对其形成进行了讨论,初步认为是成核、长大过程形成了SnO 纳米棒。     

ZnO纳米棒的制备及其气敏性研究现状

ZnO是一种多功能金属氧化物半导体材料,由于ZnO纳米棒尺寸小,比表面积大,使得ZnO纳米棒制作成气体传感器,可以提高气敏传感器的灵敏度和响应速度,降低工作温度.综述了近年来ZnO纳米棒的制备方法,展望了其在气敏性方面的应用前景.     

Pt掺杂SnO2花状纳米结构的合成及其气敏性能的研究

用原位掺杂法制备了Pt/SnO2花状纳米结构.通过控制反应源物中n(Pt4+)/n(Sn4+)比率,可以获得不同Pt掺杂量的复合纳米结构.采用SEM、XRD、TEM和Raman光谱对样品的形貌、结构等进行了分析,并测试了材料的NH3气体敏感性能.结果表明,Pt掺杂的SnO2纳米花大小约为2μm,由平均直径为180nm,...     

纳米SnO_2/SiO_2复合材料的制备及其对H_2气敏性研究

采用锡粒氧化法合成纳米二氧化锡(SnO2),并以KH-550为改性剂,对纳米二氧化锡进行表面化学修饰,制得SnO2/SiO2复合材料,研究了不同条件下制得的SnO2/SiO2复合材料对H2的气敏性能。实验结果表明较佳的SnO2/SiO2复合材料制备工艺条件为:室温条件下,改性剂与纳米二氧化锡质量百分比为9%,在甲苯溶剂中反应3h。制备的SnO2/SiO2复合材料对1000ppm H2的气体灵敏度为37.506。     

半导体SnO2纳米晶态粉体显微结构对气敏传感器性能的影响

用ＸＲＤ、ＳＥＭ手段分析了共沉淀工艺和水热合成技术制备的半导体ＳｎＯ２纳米晶态粉体及其厚膜陶瓷材料的显微结构,结果表明两种粉体的晶粒尺寸大约７ｎｍ,但两种粉体的ＸＲＤ照片差异较大。用水热合成技术制备的粉体其颗粒是由纳米晶粒团聚而成,颗凿尺寸大约３００ｎｍ左右,具有较大的表面活性,而具有较大的表面活性,而用共沉淀工艺制备的粉体,颗粒分布较宽,活性差。两种粉体的显微结构对厚膜陶瓷材料显微结构的形成和Ｓ     

Cd2SnO4水热制备及其气敏性能研究

以SnCl4.5H2O、CdCl2·1/2H2O和NaOH为原料,采用水热法制备了Cd2SnO4粒子。通过XRD和SEM对其物相和形貌进行了分析,并将其制成气敏元件,进行气敏性能测试。结果表明制得的Cd2SnO4粒子为多面体,对乙醇、丙酮和三乙胺有较高的灵敏度和好的响应-恢复特性。     

SnO2纳米棒的固相反应制备与表征

利用室温固相反应方法,合成了SnO2纳米颗粒前驱物.在NaCl、KCl等熔盐介质中,在600～785℃对前驱物进行焙烧,前驱物纳米颗粒自组装生长形成SnO2纳米棒.利用TEM、XRD和XPS对SnO2纳米棒形貌、成分进行了表征和分析,SnO2纳米棒直径为20～80 nm,长度从几百纳米到几个微米.研究了SnO2纳米颗粒前驱体熔盐介质中的生长,探讨了SnO2纳米颗粒在熔盐介质中的固相转变生长机理.     

氧化锌纳米棒微球的水热制备及其气敏性质研究

以Zn粉为原料,采用水热法制备了由氧化锌纳米棒自组装而成的氧化锌纳米棒微球和氧化锌亚微米棒,对氧化锌纳米棒微球进行了镍掺杂,用x射线衍射仪和扫描电镜对产物的结构和微观形貌进行了表征,探讨了反应机理,并测试了其气敏性质.研究发现,氧化锌纳米棒微球具有良好的气敏性质,对酒精和汽油具有较高的灵敏度,镍的掺杂明显提高了氧化锌纳米棒微球在酒精和汽油之间的选择性.     

一维Pt/SnO2纳米纤维的制备及NOx气敏性研究

为了制备出室温条件下对NO_x气体具有更高灵敏度和更快响应的传感器纳米材料并研究其气敏性能, 本研究通过高压静电纺丝法制备出一维Pt/SnO₂中空纳米纤维。采用XRD、SEM、TEM等表征手段对其结构和形貌进行研究, 同时进行了NO_x的气敏性能测试并予以探讨。研究结果表明: Pt/SnO₂纳米材料是一维中空管状及类似管状结构; 当Pt掺杂量为0.3wt%、NO_x浓度为9.7×10^-5 (V/V)时, NOx响应最快为11.33 s, 灵敏度最高可达109.6%; 当Pt掺杂量为0.5wt%时, 对NO_x检测限最低浓度可达2.91×10^-6 (V/V)。     

纳米SnO_2气敏材料制备的研究进展

为了解国内外SnO2气敏材料及其制备技术的研究进展,对纳米SnO2粉体材料以及膜的制备技术和研究进展进行了详细的综述,并对其未来的发展趋势进行了展望。结果认为,SnO2纳米粉体与SnO2膜等气敏材料的制备与使用仍是今后一段时间内重点发展对象;制备技术的不断成熟将使SnO2纳米功能材料作为气敏材料而深入研究和广泛应用,结合掺杂等手段,将进一步推动SnO2气敏元件的高效微型、集成化、智能化发展。     

Hydrothermal synthesis of different SnO2 nanosheets with CO gas sensing properties

In this work, 2D SnO₂ nanosheets were synthesized via a polyvinylpyrrolidone (PVP)-assisted hydrothermal method. X-ray diffraction and scanning electron microscopy were used to examine the chemical composition and nanostructures. It was found that the concentration of PVP played a critical role in governing the assembly process of nanostructures. Further, their gas-sensing performances were investigated comprehensively. The nanosheet-III structures were found to show the most superior gas-sensing properties due to their largest specific surface and fashionable assembly.     

花状SnO2的制备及其气敏特性的研究

以乙二醇(C2H6O2)为有机溶剂,采用溶剂热法制备了花状SnO2纳米材料,并将制备的SnO2制成旁热式气敏元件.通过XRD,SEM等测试手段对SnO2纳米材料进行了表征,并初步分析了气敏元件对丙酮的敏感机理.制备的SnO2材料是由粒径约为10 nm的颗粒有规则的堆叠而成的直径约为3～4μm的花瓣清晰的多孔分级花状结构.研究发现,气敏元件对丙酮气体有很好的响应灵敏度.在最佳工作温度(350℃)时,检测的丙酮体积分数最低为1×10-6.对100 ppm丙酮的响应及恢复时间分别为40和50 s.且气敏元件对丙酮气体的响应灵敏度远高于对苯、甲苯、甲醇、甲醛、氨等气体的响应灵敏度.     

Synthesis and gas sensing properties of novel SnO2 nanorods

We report the microstructures and gas sensing properties of two novel SnO₂ nanorods prepared by hydrothermal method with the utilizing of cetyltrimethylammonium bromide and polyethylene glycol. The structures and morphologies of the dense and porous nanorods were characterized by means of powder X-ray diffraction and scanning electron microscopy. The gas sensing performances towards ethanol of the two samples were investigated. The results show that the porous SnO₂ nanorods display excellent gas response to ethanol, indicating SnO₂ as a potential gas sensing material for broad applications.     

Nanowires assembled SnO2 nanopolyhedrons with enhanced gas sensing properties

Self-assembly of one-dimensional nanoscale building blocks into functional 2-D or 3-D complex superstructures has stimulated a great deal of interest. We report the synthesis and characterization of nanopolyhedrons assembled from ultrathin SnO(2) nanowires based on the sodium dodecyl sulfate (SDS)-assisted hydrothermal process. As-synthesized SnO(2) nanopolyhedrons have uniform diameters around 300 nm and are self-assembled by numerous ultrathin SnO(2) nanowires with diameters of 5-10 nm. The growth mechanism was also studied by investigating the samples synthesized at different reaction time. Thin films of the assembled SnO(2) nanopolyhedrons were configured as high performance sensors to detect methanol, ethanol, and acetone, which exhibited 1 ppm sensitivity, very fast response and recovery times (several seconds for different gases with concentrations of 1-200 ppm) to all the target gases and highly selective detection to acetone.     

Correlation between structural properties and gas sensing characteristics of SnO2 based gas sensors

Undoped polycrystalline tin oxide sintered in the temperature range 500–1000 °C has been comprehensively characterized with respect to its response to CO, methane and H₂. Results obtained at an operating temperature of 300 °C show that increasing the sintering temperature leads to a gradual increase in CO sensitivity which reaches a maximum after sintering at 800 °C.     

Needle-like Zn-doped SnO2 nanorods with enhanced photocatalytic and gas sensing properties

Zn-doped SnO(2) nanorods have been prepared by a simple hydrothermal method on a large scale. The as-prepared samples were characterized by x-ray powder diffraction, scanning electron microscope, transmission electron microscope, energy dispersive spectrometer, x-ray photoelectron spectroscopy, UV-vis absorption spectra and photoluminescence spectra. Studies found that the products are needle-like single-crystalline nanorods grown along the [[Formula: see text]] orientation. The photocatalytic properties of the synthesized Zn-doped SnO(2) were investigated by decomposing acid fuchsine, showing much higher photocatalytic activity than pure SnO(2) nanorods and bulk SnO(2) powders. An enhanced gas sensing ability toward methanal, ethanol and acetone gases is also achieved in high sensitivity and fast response. The origins of the enhanced performances are discussed.     

SnO/sub 2/ gas sensing array for combustible and explosive gas leakage recognition

A gas-sensing array with ten different SnO/sub 2/ sensors was fabricated on a substrate for the purpose of recognizing various kinds and quantities of indoor combustible gas leakages, such as methane, propane, butane, LPG, and carbon monoxide, within their respective threshold limit value (TLV) and lower explosion limit (LEL) range. Nano-sized sensing materials with high surface areas were prepared by coprecipitating SnCl/sub 4/ with Ca and Pt, while the sensing patterns of the SnO/sub 2/-based sensors were differentiated by utilizing different additives. The sensors in the sensor array were designed to produce a uniform thermal distribution along with a high and differentiated sensitivity and reproducibility for low concentrations below 100 ppm. Using the sensing signals of the array, an electronic nose system was then applied to classify and identify simple/mixed explosive gas leakages. A gas pattern recognizer was implemented using a neuro-fuzzy network and multi-layer neural network, including an error-back-propagation learning algorithm. Simulation and experimental results confirmed that the proposed gas recognition system was effective in identifying explosive and hazardous gas leakages. The electronic nose in conjunction with a neuro-fuzzy network was also implemented using a digital signal processor (DSP).