高温固相法制备ZnO:Zn荧光粉的研究

采用高温固相法制备ZnO∶Zn绿色发光粉体。XRD分析、荧光光谱分析结果表明 :在固相法制备ZnO∶Zn中 ,制备原料所用ZnO、C的最佳摩尔比在 2∶3,反应最佳温度为 110 0 0C。     

沉淀法制备ZnO超细粉及其对乙醇气敏性研究

利用直接沉淀法制备ZnO超细粉 ,通过改变沉淀剂类型、浓度、煅烧温度等条件选择制备ZnO超细粉的最佳工艺条件。利用激光散射测定其粒径。利用X 射线衍射对ZnO超细粉进行分析 ,并对ZnO超细粉的气敏性进行研究。     

氧化锌薄膜研究的新进展

ZnO薄膜是一种具有优良的压电、光电、气敏、压敏等性质的材料.ZnO薄膜的制备方法多样,薄膜的性质取决于不同的掺杂组分,并与制备工艺紧密相关.简述了ZnO薄膜的制备方法与基本性质与应用,分析了ZnO薄膜研究、应用与开发现状,展望了产业化发展前景.     

氧化锌压敏电阻器低成本化制备技术研究进展

ZnO压敏陶瓷具有优异的非线性特性,广泛应用于电子仪器和电力装置领域。为了满足电子元器件低成本化发展的要求,必须开发出烧结温度低、周期短、电极成本低的ZnO压敏陶瓷体系。总结了当前ZnO压敏陶瓷低成本化制备的研究进展,同时分析了ZnO压敏陶瓷低成本化制备的发展趋势。     

温度对Fe、Co掺杂ZnO纳米材料光学性质的影响

采用改进的微乳液法制备了Fe、Co掺杂ZnO纳米材料,并对制备材料的结构和形貌分别进行了X射线衍射(XRD)及扫描电子显微镜(SEM)表征。为了明确温度对ZnO纳米材料光学性质的影响,使用温控仪进行降温操作,对制备的ZnO及Fe、Co掺杂ZnO材料进行了光学性质的对比研究,得到变温条件下ZnO及Fe、Co掺杂ZnO纳米材料随温度改变而变化的发光光谱。并分析了Fe、Co掺杂导致缺陷能级的改变,进而分析了其对ZnO纳米材料发光特性的影响。     

耐高温柔性Mica/ZnO薄膜的制备与表征

以氟晶云母片为衬底，进行柔性ZnO透明导电薄膜(Mica/ZnO)的制备与表征。利用XRD和SEM表征可知，晶种水热法比直接水热法更有利于制备Mica/ZnO薄膜。研究发现，晶种水热法制备Mica/ZnO薄膜分为颗粒状ZnO晶体生长阶段、颗粒状ZnO晶体成长为棒状ZnO晶体阶段和棒状ZnO晶体成长三个阶段。采用晶种水热法制备Mica/ZnO薄膜适宜的晶化时间为26h,制备的致密棒状ZnO晶体长度约500nm左右。制备的Mica/ZnO薄膜可耐500℃以上的高温，为研究耐高温柔性ZnO透明导电薄膜提供更为丰富的柔性衬底材料和制备方法。     

Zn取向对氧化法制备ZnO薄膜光致发光性能的影响研究

先利用电阻加热真空蒸发法制备(101)和(002)优先取向的金属Zn薄膜,而后氧化处理制备ZnO薄膜。并对制备的ZnO薄膜进行了XRD,SEM,紫外-可见光吸收谱和光致发光(PL)分析。XRD结果显示制备的ZnO薄膜中有未完全氧化的金属Zn。吸收谱结果发现未完全氧化的ZnO薄膜具有强烈的紫外吸收。PL谱结果显示该法制备的ZnO薄膜具有很高的PL强度,而且(101)前驱金属膜制备的ZnO比(002)前驱金属膜制备的试样具有更高的PL强度。未完全氧化的Zn所形成的缺陷是PL强度较高的原因,SEM结果显示的ZnO薄膜表面粗糙度较大引起强烈的紫外吸收也是激发光强度高的原因之一。     

直接沉淀法制备纳米ZnO

以ZnCl2 为原料 ,直接沉淀法制备ZnO纳米粒子 ;研究了制备过程中Zn2 + 浓度、焙烧温度等条件对ZnO纳米晶体粒径的影响 ,并对其机理进行了分析。实验结果表明 ,较小的反应浓度可以获得较小的晶体粒径 ;在其它反应条件相同的情况下 ,制备的纳米ZnO粒子 ,其晶粒尺寸随着焙烧温度的增加 ,晶粒逐渐增大 ,与体相ZnO粒子相比 ,纳米ZnO粒子在紫外区光吸收能力显著增强 ,为ZnO的应用开辟了更为广阔的前景。     

新型工艺制备ZnO薄膜的结构与形貌研究

采用了一种新型工艺制备ZnO薄膜。新工艺采用二步法,首先在N型Si(100)衬底上用离子束沉积溅射一层金属Zn膜,然后通过热氧化金属Zn膜制备ZnO薄膜。通过X射线衍射、原子力显微镜对不同制备工艺下的ZnO薄膜进行结构与形貌的分析比较。研究表明,Zn膜的离子束溅射沉积时间、热氧化时间和辅助枪的离子束对热氧化后的ZnO薄膜再轰击处理对ZnO薄膜的结构与形貌都会产生影响。     

纳米氧化锌制备条件的优化研究

按L9(34)设计试验制备纳米ZnO粉体,以反应温度x1、煅烧温度x2和煅烧时间x3为变量,ZnO对甲基橙溶液的光催化降解脱色率DC为目标响应值,采用PSO-二次回归方法建模,经非线性规划基于该模型寻优,获得试验设计范围内最优化的ZnO制备条件.该条件下制备的ZnO粉体光催化性能明显优于按直观分析法分析得出的优化条件下制备的ZnO,也明显优于市售的KY-ZnO-02产品.借助大大缩短试验次数的试验设计建模是实现制备工艺优化的一条有效途径.     

不同Sol-Gel前躯体体系制备纳米ZnO粉体的研究

为研究不同溶胶前躯体体系对制备纳米ZnO粉体粒径大小的影响,采用溶胶-凝胶法分别研究了硬脂酸体系、草酸体系、高分子网络体系制备纳米ZnO粉体,并利用TG-DTA、XRD、TEM对其结构、形貌和粒径进行了表征.在3种体系中,高分子网络体系所得粉体粒径最小,粒径在30～40nm,粒径大小均匀,团聚较少.硬脂酸体系得到ZnO粉末粒径较小,范围分布在30～50nm,分散性较好.草酸体系制得ZnO粉末粒径相对较大,在40～60nm,有轻微团聚.     

ZnO纳米粉对压敏陶瓷材料显微结构和电学特性的影响

用ｓｏｌ－ｇｅｌ方法制备掺杂的ＺｎＯ纳米粉体，分析讨论了这种粉体对材料显微结构，材料电学特性如非线性系数，压敏电压和介电特性的影响，与传统方法制成的粉体相比，ｓｏｌ－ｇｅｌ方法制成的纳米粉人有掺杂均匀，晶粒尺寸分布均匀，其电学特性得到较大提高。     

La3+离子掺杂对纳米ZnO光催化性能的影响

采用共沉淀法,选择尿素为沉淀剂,制备了一系列不同La3 掺杂浓度的纳米ZnO粉体.讨论了不同掺杂浓度的样品催化降解甲基橙的光催化活性,并通过X射线衍射(XRD)和透射电镜(TEM)等分析测试手段研究了粉体样品的相组成、晶胞参数和晶粒大小对光催化性能的影响.结果表明:La3 掺杂能够显著提高ZnO粒子的光催化活性.最佳掺杂浓度为100:0.2;最后提出了La3 改善纳米ZnO粉体光催化性能的作用机制.     

纳米氧化锌改性胶粉/天然橡胶复合材料的制备及性能

利用纳米氧化锌采用直接混合、球磨分散混合及超声分散混合法对胶粉进行了改性．并在开炼机上制备了纳米氧化锌改性胶粉／天然橡胶复舍材料。利用扫描电镜对纳米氧化锌的分散效果进行了考察，并测试了填充改性胶粉的天然橡胶复合材料的拉伸性能、撕裂强度及耐磨性。结果表明，超声分散混合法得到的试样中纳米氧化锌的分散情况较好，其中采用钛酸酯偶联剂改性的试样的性能最佳，与纳米氧化锌直接混合和添加活性氧化锌的试样相比其拉伸强度分别提高32％和55％，扯断伸长率分别提高7％和22％，撕裂强度分别提高28％和39％．耐磨性分别提高17％和7％。     

Production and characterization of ZnO nanocrystals obtained by solochemical processing at different temperatures

The semiconductor zinc oxide (ZnO) has been widely used because it presents exclusive novel physical and chemical properties at the nanometer scale. In this work, ZnO nanocrystals were synthesized via solochemical processing in a few hours without any subsequent treatment. ZnCl2 and NaOH were adopted as synthesis precursors. ZnO production was realized at different reaction temperatures to verify the effect of this parameter on synthesis. The synthesis temperatures studied were 50 degrees C, 70 degrees C and 90 degrees C. The materials obtained at different reaction temperatures were characterized by X-ray diffraction (XRD) and the Rietveld method. The size and morphology of the ZnO particles obtained at 50 degrees C were evaluated by transmission electron microscopy (TEM). ZnO powders have hexagonal wurtzite structure and nanometric-sized crystallites. Microstrain increased and the average crystallite size decreased with the increase in reaction temperature.     

ZnO纳米晶粉末和电沉积Ni薄层透射电镜样品的制备和观察

制备了ZnO纳米晶粉末和电沉积Ni镀层的透射电子显微镜样品,并利用透射电子显微镜对其进行了观察。     

Controlled mechanochemically assisted synthesis of ZnO nanopowders in the presence of oxalic acid

In this study, the ZnO nanopowders were synthesized by mechanochemical processing with a successive thermal decomposition reaction. The initial reactants mixture of zinc chloride and oxalic acid was milled from 30 min to 4 h and thermally treated for 1 h at 450 °C. The influence of both, oxalic acid and the duration of milling, on the crystal structure, average crystallite size, average particle size, and the morphology of ZnO nanopowders were investigated. The qualitative analysis was performed using X-ray diffraction and Raman spectroscopy techniques. While the XRD analysis shows perfect long-range order and pure wurtzite structure of the synthesized ZnO powders, Raman spectroscopy indicates a different middle-range order; in addition, according to Raman spectra, it is found that lattice defects and impurities introduced in ZnO crystal structure depend on milling duration, in spite of applied thermal treatment. The particle size distribution was measured by laser diffraction, whereas the morphology of the powders was determined by scanning electron microscopy. Impurity contamination was studied using inductively coupled plasma analysis. The obtained results showed that the applied two-step method is appropriate for the synthesis of high crystalline ZnO nanopowders, with uniform spherical particles with diameter between 20 and 50 nm. Profound effect of aqueous solution of oxalic acid to prevent agglomeration of final product is presented.     

Effect of aerosol carriers on ultrasonically prepared nanocrystalline ZnO powders

Nanocrystalline ZnO powders were synthesized using ultrasonic spraying and decomposition technique. The compressed air and pure oxygen were used as aerosol carriers. Effect of aerosol carriers on ultrasonically atomized nanocrystalline ZnO powders was studied. The powders were characterized using X-ray diffraction, transmission electron microscopy (TEM), electron diffraction, absorption spectroscopy and photoluminescence. The influence of air and oxygen on crystallite morphology was studied using TEM. It was confirmed from TEM analysis that the crystallites were nearly spherical in powder prepared in the presence of compressed air. In the presence of pure oxygen, the crystallites could acquire regular hexagonal shape. Complete hexagonal shapes may be due to sufficient (100%) supply of pure oxygen during the process of formation of ZnO nanocrystallite. The powder with regular shaped crystallites could be highly pure and also stoichiometric in nature. Pure oxygen could therefore be more advantageous as carrier than air for production of nanocrystalline ZnO powder. The effect of aerosol carriers (compressed air and pure oxygen) on crystallite morphology of nanocrystalline ZnO powders is reported in this article.     

纳米氧化锆粉体的表面改性研究

本文初步研究了己二酸，硬脂酸对纳米氧化锆陶瓷粉体的表面改性作用及其对粉体的极性和流动性的影响。实验结果表明，己二酸，硬脂酸中的羧基与纳米氧化锆粉体颗粒表面的羟基发生类似于酸和醇的酯化反应，并在其表面形成单分子膜。经过表面改性的纳米氧化锆粉体由极性转化为非极性，同时表现出良好的流动性能。     

Cu2+掺杂ZnO纳米棒的制备及气敏性能研究

通过溶剂热法(无水乙醇)制备了Cu2+(0～6mol%)掺杂ZnO纳米棒粉体,采用X射线衍射仪和扫描电镜对掺杂ZnO纳米粉体的晶体结构和微观形貌进行了表征.研究了Cu2+掺杂比例、溶剂热反应温度及时间对材料气敏性能的影响;考察ZnO(120℃,10h)和3mol%Cu2+掺杂ZnO(120℃,10h)粉体对应元件对甲醛、乙酸、甲苯、乙醇、丙酮、三甲胺等六种气体的气敏性能.结果表明:通过溶剂热法制备的ZnO粉体为纳米棒状结构,棒长度和直径随Cu2+掺杂比例不同发生变化;3mol%Cu2+掺杂ZnO(120℃,10h)样品对应元件对低浓度乙醇有很好的选择性,在395℃工作温度下对1×10–3乙醇的灵敏度为380.5,响应和脱附时间分别为5 s和40 s,对1×10–6乙醇的灵敏度可达4.2.