物理化学综合实验设计一纳米ZnO的制备、表征及光催化性能测试

分别采用水热和沉淀法制备ZnO光催化剂，利用X射线粉末衍射（XRD）和扫描电镜（SEM）对其物相和外貌进行分析观测．了解表征手段所反映的材料的物质结构信息。通过降解亚甲基蓝实验比较不同制备条件下所得ZnO的光催化性能。了解催化剂制备方法对其晶相、形貌及催化性能的影响。     

Sb2S3晶体的水热合成及表征

在水热条件下制备了Sb2S3晶体,用X射线粉末衍射（XRD）、扫描电镜（SEM）分别对Sb2S3晶体的物相及形貌进行了表征分析。实验结果表明,硫源、反应温度、反应时间会影响样品的形貌和粒径。     

微波加热制备纳米ZnO粉体及其表征

以硝酸锌和氢氧化钠为原料,三乙醇胺为表面活性剂,采用微波加热沸腾回流,在不同的反应条件下制备出了平均粒径为25～80nm的纳米级ZnO粉体。采用X射线衍射(XRD)、扫描电镜(SEM)及粒度分布仪等测试手段,对产品的物相、形貌和粒度分布进行了表征。实验结果表明,利用微波加热制备出的纳米ZnO粉体结晶性能良好,粒径大小均匀;三乙醇胺的加入,明显地改变了氧化锌的结晶行为,晶体形貌由原来的棒状变为准球形,粒径减小到纳米级。     

氧化锌纳米晶的制备及表征研究

采用溶胶-凝胶法以醋酸锌、草酸为原料制备ZnO纳米晶,借助X射线粉末衍射(XRD)、扫描电子显微镜(SEM)等表征手段进行了物相分析和微观形貌表征.结果 表明,制备ZnO纳米晶适宜工艺条件为:凝胶化温度80℃,凝胶化时长1.5h,焙烧温度600℃,焙烧时间3h.X射线衍射图表明ZnO纳米晶在(101)晶面出现取向生长....     

ZnSn(OH)6空心粒子的制备及光催化性能

分别以锌离子和氧化锌作为锌源,利用水热法制备了ZnSn(OH)6粒子.锌的存在状态影响反应过程,进而影响了样品的物相、形貌和性能.以锌离子为锌源时,可以得到立方相ZnSn(OH)6空心粒子,若以氧化锌作为锌源,会得到ZnSn(OH)6/SnO2混合相,没有生成空心结构.在相同的制备条件下,制备了ZnO和SnO2作为对比样品.样品的结构、形貌和尺寸采用X射线粉末衍射(XRD)、透射电镜(TEM)和扫描电镜(SEM)等测试手段进行了表征;并以甲基橙为降解对象,研究了不同样品的光催化性能.与ZnSn(OH)6/SnO2混合相、ZnO和SnO2相比,ZnSn(OH)6空心粒子具有很强的吸附能力和大的禁带宽度,表现出优异的光催化性能.     

共掺杂ZnO纳米材料的制备及光学性能研究

利用共沉淀法制备了Y和Cd共掺杂的ZnO纳米材料。X-射线衍射分析表明,样品为单一相的ZnO纤锌矿结构,随着掺杂量的增加,样品的晶粒尺寸减小。光学性能测试结果表明,样品具有较强的紫外发射峰和较弱的可见光发射峰,紫外发射峰强度随着掺杂量的增加而减弱并发生红移。     

Si(111)衬底上生长的ZnO薄膜的光学特性研究

利用等离子体分子束外延(P-MBE)设备在Si(111)衬底上制备了高质量的ZnO薄膜.通过扫描电镜观察了ZnO薄膜的表面形貌为的六角结构.X射线衍射谱显示ZnO薄膜为C轴择优取向的,ZnO(002)取向X射线衍射峰的最大半宽度仅0.18°.并通过室温和变温发光谱对ZnO薄膜的发光特性进行了研究.在低温下ZnO的发光以...     

氢氧化钠对纳米二氧化锆的合成和光催化性能的影响

纳米二氧化锆(ZrO2)是一种重要的功能材料,具有光催化特性,在光催化降解有机污染物方面有较好的应用前景。以氧氯化锆、色氨酸和氢氧化钠为原料制备了系列纳米二氧化锆样品,利用扫描电镜和X射线粉末衍射进行了结构和形貌表征,研究了所得纳米二氧化锆样品在紫外光下对罗丹明B溶液的催化降解作用。结果表明,在制备纳米二氧化锆时加入适量的氢氧化钠会促进其晶相结构由单斜相向四方相转变,降低晶粒粒径,并增强光催化性能。     

稀土对激光熔覆生物陶瓷涂层性能的影响

采用激光熔覆的工艺方法制备出含稀土的硼CaP陶瓷涂层,通过X射线衍射仪(XRD)、扫描电镜(SEM)和体外模拟体液(SBF)浸泡实验,对涂层物相组成、组织形貌和生物活性进行了研究。结果表明添加稀土氧化物La2O3之后,羟基磷灰石衍射峰明显上升,晶粒明显细化,涂层表面沉积的类骨磷灰石明显增多,生物活性明显改善。     

Lu_2Si_2O_7:Eu闪烁陶瓷粉体的溶胶–凝胶法制备及表征(英文)

使用溶胶-凝胶法制备了Lu2Si2O7:Eu闪烁陶瓷前驱粉体.通过X射线衍射仪和真空紫外荧光光谱仪对粉体物相、晶粒尺寸及粉末的发光性能进行了表征.结果表明:粉体在1150℃左右烧结时开始成相,晶粒大小随烧结温度的升高而增加.结合X射线衍射和真空紫外发射光谱的结果可以推断样品的紫外激发发射峰强度随晶粒尺寸的增大而增强.     

铟掺杂氧化锌纳米线的制备及光致发光特性

采用化学气相沉积法合成了高质量的铟(In)掺杂的氧化锌单晶纳米线。利用扫描电子显微镜、透射电子显微镜和粉末X射线衍射对其形貌与结构进行了表征。结果表明:纳米线的直径约为30nm,粗细均匀,具有六角纤锌矿结构。在纳米线的变温光致发光光谱中,由于In的掺杂,只观察到紫外发射峰,未见可见光发射峰;低温下的紫外发射来自于施主-受主对(donor-acceptor pair,DAP)的跃迁。随着温度的升高,DAP的跃迁逐渐减弱,在高于140K时,紫外发射来自于自由电子到中性受主(free-electron-to-neutral-acceptor,eA0)的跃迁。     

Seaweed‐ZnO composite for better antibacterial properties

Brown seaweed Padina tetrastromatica (PTS)‐Zinc oxide (ZnO) composites were prepared by chemical precipitation method. The characteristic peaks of PTS and ZnO were confirmed by Fourier transform infrared spectroscopy. X‐ray diffraction study was confirmed the formation of ZnO with hexagonal wurtzite phase. Surface morphology and particle's distribution of ZnO were characterized by scanning electron microscopy. Transmission Electron microscopy image reveals that ZnO nanorods are in the size range of 14–164 nm having uniformly blended with polysaccharide of seaweed. Ultraviolet‐Visible absorption spectra indicated the sharp absorption peak at 219 nm and broad absorption peak in the 250–350 nm range. Fluorescence spectra shows the broad blue‐violet emissions is around at 380–480 nm. Because of the interaction between polysaccharide and ZnO nanorods/particles, the prepared seaweed‐ZnO composite exhibit better antibacterial activity than pure ZnO nanoparticles. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40948.     

Application of impregnation combustion method for fabrication of nanostructure CuO/ZnO composite oxide: XRD,FESEM, DRS and FTIR study

Nanostructured CuO/ZnO composite oxide was prepared by a novel impregnation combustion method using copper nitrate and zinc oxide tetrapod. The X-ray diffraction patterns revealed that CuO/ZnO composite oxide was formed. The effects of different impregnation combustion parameters on the properties of composite were studied by field-emission scanning electron microscope (FESEM), powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and UV–vis diffuse reflectance spectrum (DRS). The synthesis of ZnO–CuO nanocomposites through impregnation of a zinc oxide tetrapod with copper nitrate aqueous sodium carbonate solutions is reported. During thermal treatment the samples evolve toward the formation of nanocrystalline ZnO particles (zincite phase) dispersed onto tenorite, CuO annealed at 450 °C. XRD patterns of the precursors calcined at 450 °C showed the formation of the zincite–tenorite phases. Field emission scanning electron microscopy (FESEM) exhibited loosely agglomerated hexagonal particles with uniform morphology having a size around 50 nm.     

沉淀法制备花状ZnO粉体及性能研究

以二水合乙酸锌提供锌源,氨水调节pH值,聚乙二醇-2000为改性剂,采用沉淀法在一定的工艺条件下得到了花状ZnO粉体。并以SEM、TEM及XRD等测试手段对产物的形貌及结构方面进行了表征。利用X射线衍射仪进行结晶结构分析,表明花状ZnO为六方纤锌矿结构;利用场发射电子扫描电镜进行样品形貌分析,表明花状结构ZnO是由纺锤状棒状结构组成,棒的长径比为2.10;利用场发射透射电镜进行结晶结构分析,表明花状ZnO是单晶与多晶的混合体,室温光致发光谱表明花状ZnO在380nm左右存在紫外发射峰。     

焙烧气氛对柠檬酸溶胶-凝胶法合成混合导体SrFeCo0.5Oy的影响

用柠檬酸溶胶-凝胶法合成SrFeCo0.5Oy混合导体,研究了焙烧气氛对合成过程的影响.利用XRD和SEM研究了粉体样品的晶体结构组成和形貌,利用阿基米德法测定了块体样品的密度.结果表明:在氧气气氛中焙烧可以得到以钙钛矿相为主晶相的SrFeCo0.5Oy,粉体为片状,颗粒较小,而在氩气中焙烧得到的样品以正交相为主要成分,粉体为圆形球状,颗粒较大;在氧气中低温烧结的块状样品的密度低于在氩气中烧结的样品的密度.探讨了样品在不同气氛下焙烧的反应机理.     

Optical and photocatalytic properties of La-doped ZnO nanoparticles prepared via precipitation and mechanical milling method

The synthetic method used for preparing ZnO nanoparticles strongly influenced the products obtained. The ZnO powders incorporated more La when prepared by the mechanical milling method whereas the La₂O₃/ZnO composite nanoparticles were formed better using the precipitation method. The phase formations were detected by the X-ray diffraction technique and the morphology of the samples was followed by scanning electron microscopy. The La contents affected the crystallite size. This was explained by the formation of LaOZn on the surface of the samples and by the Zener pinning effect. The band gap energy of the samples was influenced by repulsion between the valence and conduction bands and the presence of a secondary phase. The photocatalytic degradation of a methylene blue solution by the samples depended upon the number of oxygen vacancies.     

沉淀法制备花状ZnO粉体及性能研究

以二水合乙酸锌提供锌源，氨水调节pH值，聚乙二醇-2000为改性剂，采用沉淀法在一定的工艺条件下得到了花状ZnO粉体。并以SEM、TEM及XRD等测试手段对产物的形貌及结构方面进行了表征。利用X射线衍射仪进行结晶结构分析，表明花状ZnO为六方纤锌矿结构；利用场发射电子扫描电镜进行样品形貌分析，表明花状结构ZnO是由纺锤状棒状结构组成，棒的长径比为2．10；利用场发射透射电镜进行结晶结构分析，表明花状ZnO是单晶与多晶的混合体，室温光致发光谱表明花状ZnO在380nm左右存在紫外发射峰。     

Conventional HP sintering of asymmetric hexagonal structure Yb3+-doped Sr5(PO4)3F transparent ceramic without additives

The 2 at.% Yb³⁺:Sr₅(PO₄)₃F (S-FAP) polycrystalline transparent ceramic with asymmetric hexagonal structures has been synthesized by vacuum hot-pressing the nanoparticles prepared via coprecipitation method. X-ray diffraction results of powder and ceramic indicate that their phase peaks are well matched to the crystal structure of S-FAP. The average particle size of 35.5 nm has been exhibited by powder scanning electron microscopy images, and subsequent images of the ceramic cross section and surface morphology revealed a homogenous and compact microstructure with an average grain size of around 220 nm. The relationship between the optical loss caused by the scattering of anisotropic ceramic grains and the optical transmittance of ceramics was revealed in the hexagonal S-FAP transparent ceramics with different thicknesses. The in-line transmittance of hot-pressed ceramics with 1.5-mm thickness achieved 79.95% at 1100-nm wavelength, and the room-temperature absorption and emission spectra of Yb³⁺ in S-FAP polycrystalline ceramic matrix were measured using a spectrofluorometer.     

Sol–Gel Synthesis and Characterization of Alumina–Calcium Hexaaluminate Composites

Boehmite sol was prepared by hot water hydrolysis of aluminum iso-propoxide using nitric acid as the catalyst. Calcium nitrate to yield 0–20 vol% calcia was added to the boehmite sol. The boehmite with additives was calcined at 600°C for 3 h. The calcined powder was milled at 230 rpm for 6 h and particle size was measured using Laser particle size analyzer. The powder samples were calcined at 1600°C for 3 h and the formation of calcium hexaaluminate was discussed using phase diagram, transmission electron microscope, energy dispersive spectra, and X-ray diffraction spectra. The powder samples calcined at 600°C for 3 h were compacted into cylindrical pellets and sintered at temperatures ranging from 1400° to 1600°C for 6 h and the formation of hexaaluminate (platelike) grains were confirmed using Scanning electron microscope and optical microscopy.