类积木状ZnO气体传感器的制备及其气敏特性研究

采用水热法合成了类积木状ZnO纳米结构,利用X射线衍射仪(XRD)、X射线能谱分析仪(EDS)和扫描电子显微镜(SEM)对制备的ZnO纳米结构的物相、化学组分及微观形貌进行了表征与分析。对基于ZnO纳米结构的气体传感器进行甲烷气敏特性测试,测试结果表明:该传感器的最佳工作电压为5 V,在该电压下对体积分数为200×10-6甲烷气体的灵敏度可高达55.4%,最低检测限为1×10-6。     

基于微通道的ZnO纳米棒生物荧光检测研究

利用种子法和水热合成技术,分别在常规条件下和阵列式微通道中制备氧化锌(ZnO)纳米棒.采用扫描电子显微镜(SEM)、X射线衍射(XRD)等分析方法表征ZnO纳米棒的表面形貌特点和晶体结构.结果表明:微通道中制备的ZnO纳米棒的比表面积、结晶度和c轴取向性均有较大程度的提高.同时,建立了基于阵列式微通道的ZnO纳米棒生物荧光检测方法,利用ZnO纳米棒可显著增强荧光信号,对异硫氰酸荧光素标记的羊抗牛IgG抗体的检测限为1×10-4 μg/mL.     

氧等离子体处理ZnO纳米纤维材料的制备及其对丙酮气敏性能的研究

采用静电纺丝法制备了ZnO纳米纤维材料并使用氧等离子体对其进行表面处理.通过X射线衍射(XRD),扫描电子显微镜(SEM),BET比表面积测试以及X射线光电子能谱分析(XPS)等手段对样品的结构与形貌进行了表征分析.将氧等离子体处理前后的ZnO纳米纤维分别制成气体传感器,对浓度为1×10-6~100×10-6(体积分数)丙酮气体的敏感特性进行了测试分析.测试结果表明,氧等离子体处理后的ZnO纳米纤维响应值较未处理的ZnO纳米纤维有大幅度的提升,最佳工作温度也有所降低,且对甲醛、苯、甲苯、二甲苯等几种干扰气体表现出更好的选择性.从晶粒间势垒和耗尽层厚度等角度初步分析了氧等离子体处理改善ZnO气敏特性的机理.     

基于ZnO传感器的高流速气体压力测试

针对机械系统中气体轴承间气膜压力的分布检测,提出并研发了一种基于ZnO传感器的检测方法。ZnO纳米颗粒敏感材料采用化学沉淀法制备;用X射线衍射和扫描电镜对其进行了表征。利用ZnO传感器的响应电压与动态气体压力的关系,成功测试出高压动态气体的压力。分析了氧气吸附、压电效应和热传导对响应电压的影响,拟合出对应的气体压力-响应电压关系曲线,本研究为高流速气体压力的测试提供了一种新途径。     

氧化锌基乙醇气体传感器研制及特性研究

利用水热法合成了不同形貌的ZnO基纳米结构气敏材料,利用X射线衍射仪(XRD)和扫描电子显微镜 (SEM)对其进行了结构表征和分析。制备成旁热式气体传感器,测试了其对乙醇(C2H5OH)的气敏特性。实验结果表明：基于ZnO纳米花制作出的传感器比纳米球状传感器对C2H5OH具有更高的灵敏度,在200oC下对50ppm的C2H5OH灵敏度为34.7,是球状ZnO基传感器的1.7倍;两种ZnO基传感器对C2H5OH均表现出较好的重复性,在最佳工作温度下对C2H5OH的响应恢复时间均在15秒以内;最后对ZnO基C2H5OH气体传感器的气敏机理进行了讨论。     

ZnO纳米棒修饰的QCM气体传感器检测NH_3研究

主要介绍了ZnO纳米棒修饰的石英晶体微天平(QCM)气体传感器的制备与测试。采用两步法在石英晶振片表面制备直径为100 nm的ZnO纳米棒敏感膜,构成QCM NH3传感器。检测系统为自主研发的基于LabVIEW平台的QCM气体传感器频率测试软件。检测NH3的体积分数为5×10-6~50×10-6,响应时间均在10 s以内,最大频差值为10.9 Hz,响应最大频差值与NH3体积分数呈现良好的线性关系。室温条件下,ZnO纳米棒敏感膜可以完全实现吸附解吸过程,具有可逆性。该传感器性能稳定,响应灵敏,具有重复性。     

氧化锌气体传感器的制备及甲烷检测特性研究

甲烷(CH4)是电力变压器油纸绝缘中溶解的主要故障特征气体,能有效反映运行变压器油纸绝缘故障.气体传感检测是油中气体在线监测、分析的关键.基于水热法,制备了氧化锌(ZnO)纳米片和纳米球气敏材料及传感元件,基于实验室搭建的微量气体检测平台测试了其对CH4的检测特性.研究表明:基于ZnO纳米片制作的气体传感器比纳米球传感器对CH4表现出更好的气敏性能,对50μL/L CH4的最佳工作温度降低了约60℃,同时对低浓度(1μL/L～20μL/L)CH4表现出较高的线性度和长期稳定性.本研究对研制高性能的ZnO基CH4气体传感器奠定了基础.     

具有纳米结构的海胆形氧化锌的制备及其酒敏性能

以Zn(Ac)2.2H2O为原料,NH3.H2O为络合剂,在NaBH4辅助下140℃水热反应2 h制备出海胆形ZnO颗粒。采用X射线衍射仪和扫描电镜对产物进行表征。海胆形ZnO颗粒的直径约为3μm～17μm,它是由直径约为100 nm,长度约为500 nm～3μm的ZnO纳米棒自组装而成。研究了NaBH4物质的量,反应温度和时间对产物形貌的影响,结果表明,NaBH4在海胆形ZnO颗粒的形成过程中起着关键作用,提出了可能的生长机理。气敏测试结果表明,海胆形ZnO纳米颗粒在350℃对低浓度的乙醇气体具有快速敏感的传感性能。     

基于高压静电纺丝法制备P(VDF-TrFE)/ZnO/GR复合膜压电性能的研究

提出了一种利用高压静电纺丝法制备P(VDF-TrFE)/ZnO/Graphene(以下简称GR)复合纳米纤维薄膜的方法，并对其压电性能进行了研究。首先，利用扫描电镜（SEM）观测复合薄膜的表面形貌并分析其X射线衍射（XRD）图谱。其次，将薄膜封装为三明治结构的压电纳米发电机(PNG)并研究了其压电性能。结果表明，含10%ZnO、0.1%GR的P(VDF-TrFE)/ZnO/GR复合薄膜压电纳米发电机开路输出电压和短路输出电流峰值为12.6V、7.88μA，约是纯P(VDF-TrFE)薄膜的2.7倍、3.1倍。在激振力大小3.5N，频率为5HZ的条件下P(VDF-TrFE)/ZnO/GR压电纳米发电机的最大瞬时输出功率为33.85μW，持续激振21分钟后，LTC3588-1毫微功率能量收集电源可以稳定输出3.3V电压1.5s。P(VDF-TrFE)/ZnO/GR压电纳米发电机具有良好的压电性能，具有成为自供电设备的潜力。     

基于纳米ZnO-壳聚糖-酪氨酸酶生物传感器对邻苯二酚的测定

以Zn(Ac)2和N,N-二甲基甲酰胺为原料,采用水热合成法在160℃下合成出了纳米ZnO,并用X-射线衍射、透射电镜表征了所制备纳米ZnO的结构,同时以制备的纳米ZnO固定酪氨酸酶制备了多酚生物传感器,结果表明高等电点的纳米ZnO在很大程度上促进了酪氨酸酶与电极之间的直接电子传递,能够有效地用于多酚的测定.     

LPG sensing properties of ZnO films prepared by spray pyrolysis method: Effect of molarity of precursor solution

Nanocrystalline ZnO films were deposited onto glass substrates by spray pyrolysis of zinc nitrate solutions and used as a liquid petroleum gas (LPG) sensor. The dependence of the LPG sensing properties on the molar concentration of zinc nitrate solutions was investigated. The ZnO films were oriented along (0 0 2) with the hexagonal crystal structure. The grain size and grain density increased with an increase in molar concentration of zinc nitrate solutions. The gas sensing properties for LPG of the ZnO films for LPG with different grain sizes were measured at different temperatures. The maximum sensitivity of 43% at the operation temperature of 673 K was found for the ZnO film prepared by spraying a 0.1 M solution. The ZnO thin films exhibited good sensitivity and rapid response–recovery characteristics to LPG. Further, it has been shown the gas sensitivity of the ZnO gas sensor depends upon its grain size.     

Selective detection of HCHO gas using mixed oxides of ZnO/ZnSnO3

Mixed oxides of ZnO/ZnSnO₃ doped with Au element were prepared by a hydrothermal process. The crystal structure, composition and ceramic microstructure of the powders obtained were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results show that the product is the mixture of ZnO/ZnSnO₃; its particle size is about 500 nm with good dispersivity in shape. The sensitivity, selectivity, response and recovery properties of the ZnO/ZnSnO₃-based sensors were investigated by mixing a target gas in air. It is found that the sensors have remarkable sensitivity to HCHO vapor and satisfactory selectivity to other gases.     

硅基底和金刚石基底上沉积ZnO薄膜工艺研究

采用射频磁控溅射方法分别在硅基底和金刚石基底上制备ZnO薄膜,研究了硅和金刚石衬底的不同对ZnO薄膜生长机理的影响,同时分析了氩氧比和退火温度这两个工艺参数对薄膜的晶格取向和表面形貌的影响。利用XRD和AFM对ZnO压电薄膜的性能进行了测试。结果显示,金刚石基片上制备的薄膜表面状态远优于硅基片上的薄膜表面状态;在同类型基底上生长的ZnO薄膜,薄膜的晶格取向随着氩氧比的升高而增强;对于硅基底上生长的ZnO薄膜,适当的退火能够成倍地提高薄膜的c轴取向性。     

Pinecone-shaped ZnO nanostructures: Growth, optical and gas sensor properties.

Pinecone-shaped ZnO nanostructures have been fabricated on Si substrate by pulsed laser deposition. The scanning electron microscope images showed that pinecone-shaped ZnO nanostructure was 6-fold symmetry and has the rough surface on one end. X-ray diffraction, Raman spectra and X-ray photoelectron spectroscopy indicated that the ZnO nanostructures have high crystal quality and a large amount of surface states. Compared with ZnO nanowires and nanobelts, the oxygen gas sensor based on pinecone-shaped ZnO nanostructures has excellent selectivity, fast response and recover, and lower operating temperature. Meanwhile, the response properties are very stable over several circles.     

基于Al掺杂ZnO的丙酮气敏传感器以及紫外光激发对其气敏性能的影响

采用溶胶凝胶法制备的Al掺杂ZnO纳米粉末（AZO）。利用X射线衍射（XRD）和扫描电子显微镜（SEM）表征样品的晶体结构和表面形貌。采用浸渍提拉法将该样品制成旁热式气体传感器,检测其对不同气体的响应恢复特性。结果表明：Al掺杂ZnO表面粗糙,Al的掺杂能够抑制ZnO晶粒增长。当工作温度为70℃、湿度为27%RH时,4.98wt.%Al掺杂ZnO对丙酮气体具有很好的选择性,电阻灵敏度达到了14075,响应和恢复时间分别为1 s和3 s。紫外光照射可明显提高传感器的气敏特性,并降低工作温度。     

基于微接触印刷的ZnO紫外传感器特性研究

采用微接触印刷技术和水热生长方法在硅基底上实现了ZnO种子层的图案化转移与纳米线阵列的可控制备。利用X射线衍射(XRD)、能量色散谱(EDS)和扫描电子显微镜(SEM)等测试手段对制备的ZnO纳米线晶体结构、化学组分以及表面形貌进行了表征,并对制备的ZnO纳米线传感器进行了紫外特性测试。测试结果表明:随着紫外光强度的增加,传感器的光暗电流比和光响应度也随之增加。当紫外传感器偏压在4.5 V时,其光暗电流比为80.8,响应度可达4.05 A/W。     

不同形貌ZnO气敏材料的制备及影响气敏性因素分析

以锌盐和碱为原料,采用水热和溶剂热法合成了三种形貌的氧化锌粉体,利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和X射线光电子能谱仪(XPS)对产物的结构和形貌及表面化学状态进行了表征,并将粉体制备成厚膜型气敏元件,测试了其对几种还原性气体的气敏性能,结果表明:在工作温度为395℃时,三种形貌氧化锌对相同浓度的同种测试气体的灵敏度大小顺序为:菜花状氧化锌﹥棒状氧化锌﹥六棱柱状氧化锌。并对影响氧化锌材料气敏性的各种因素进行了分析。     

Room temperature ferromagnetism of Ni, (Ni, Li), (Ni, N)-doped ZnO thin films

Ni-doped ZnO thin films (Ni concentration up to 10 mol%) were generated on Si (100) substrates by a sol-gel technique. The films showed wurtzite structure and no other phase was found. The chemical state of Ni was found to be bivalent by X-ray photoelectron spectroscopy. The results of magnetic measurements at room temperature indicated that the films were ferromagnetic, and magnetic moment decreased with rise of Ni concentration. The magnetization of Ni (10 mol%)-doped ZnO film annealed in nitrogen was low...     

Gas sensing properties of ZnO thin films prepared by microcontact printing

In situ patterned zinc oxide (ZnO) thin films were prepared by precipitation of Zn(NO₃)₂/urea aqueous solution and by microcontact printing of self-assembled monolayers (SAMs) on Al/SiO₂/Si substrates. The visible precipitation of Zn(OH)₂ from the urea containing Zn(NO₃)₂ solution was enhanced by increasing the reaction temperature and the amount of urea. The optimized condition for the ZnO thin films was found to be the Zn(NO₃)₂/urea ratio of 1/8, the precipitation temperature of 80 °C, the precipitation time of 1 h and the annealing temperature of 600 °C, respectively. SAMs are formed by exposing Al/SiO₂/Si to solutions comprising of hydrophobic octadecylphosphonic acid (OPA) in tetrahydrofuran and hydrophilic 2-carboxylethylphosphonic acid (CPA) in ethanol. The ZnO thin film was then patterned with the heat treatment of Zn(OH)₂ precipitated on the surface of hydrophilic CPA. The ZnO gas sensor was exposed to different concentrations of C₃H₈ (5000 ppm), CO (250 ppm) and NO (1000 ppm) at elevated temperatures to evaluate the gas sensitivity of ZnO sensors. The optimum operating temperatures of C₃H₈, CO and NO gases showing the highest gas sensitivity were determined to be 350, 400 and 200 °C, respectively.     

Influence of sputtering power on properties of ZnO thin films fabricated by RF sputtering in room temperature

High mobility and c-axis orientated ZnO thin films were deposited on glass substrates using RF sputtering method at room temperature.Structural properties of ZnO thin films were investigated by X-ray diffraction (XRD).Surface morphology and roughness were studied with scanning electron microscopy (SEM) and atomic force microscopy (AFM).Electrical properties were measured at room temperature using a Hall effect measurement system.The influence of sputtering power on characteristics of ZnO thin films is studied.The results indicate that the sputtering powers have great influence on the crystal quality and mobility of ZnO thin films.By using optimized sputtering conditions,high crystal quality ZnO thin films with Hall mobility of 34 cm 2 /V·s at room temperature were obtained.