具有核壳结构的ZnO纳米棒@Ni-Co双氢氧化物复合物纳米片阵列的制备及其电化学性能

通过两步水热合成法制备了具有核壳结构的ZnO纳米棒@Ni-Co双氢氧化物复合材料纳米片阵列.首先,以碳布为基底,水热法生成的ZnO沉积在碳布上形成ZnO纳米棒花簇.其次,以ZnO纳米棒为模板,水热法生成的Ni-Co双氢氧化物纳米片沉积在ZnO纳米棒表面,形成ZnO纳米棒@Ni-Co双氢氧化物纳米片复合材料阵列.形貌、结构分析和电化学性能测试表明,以碳布为基底,成功地合成了以ZnO纳米棒为模板并具有核壳结构的ZnO纳米棒@Ni-Co双氢氧化物复合材料纳米片阵列,该复合材料纳米片阵列具有较大的纵横比,且分散均匀.合成的ZnO纳米棒@Ni-Co双氢氧化物复合材料纳米片阵列具有良好的电化学性能,当电流密度为1 A/g时,其比电容值可达531.6 F/g,该复合材料在超级电容器电极材料领域具有良好的应用前景.     

PEG辅助氧化锌纳米棒的水热法制备

采用PEG辅助水热法合成了ZnO纳米棒,XRD显示产物为结晶良好的六角结构晶体ZnO,PL谱表明适当退火处理后产物有较好的光致发光性能.利用TEM和SAED研究了纳米棒的形貌和生长机制,并研究了氢氧化钠浓度和反应时间对产物形态和尺寸的影响.     

Zn基片上ZnO及ZnS/ZnO复合纳米阵列的液相合成及发光性质

采用温和的溶液路线在Zn基片上合成了单晶态的ZnO纳米棒阵列、 纳米片阵列和ZnS/ZnO复合双层纳米棒阵列. 使用X射线粉末衍射仪、 扫描电子显微镜、 高分辨透射电子显微镜、 X射线光电子能谱仪等对产物的组成、 结构及形貌进行了表征. 讨论了表面活性剂在液相合成中对产物形貌的调控作用. 通过室温发射光谱的测定, 研究了所得纳米阵列材料的发光性质.     

ZnO纳米片/微棒复合体的制备、结构及光学性能

以十六烷基三甲基溴化铵(CTAB)为表面活性剂,以氯化锌和氢氧化钠为原料,在低温水热条件下制备出具有纳米片状接枝结构的ZnO微棒。通过扫描电镜(SEM)、X射线衍射(XRD)、透射电镜(TEM)、光致发光(PL)和拉曼光谱(Raman)对产物的形貌、晶体结构和光学性能进行了表征。结果表明,表面活性剂CTAB对产物最终形貌的形成具有重要作用;微棒表面所接枝的薄片为多晶结构;产物光致发光峰是较少见的弱蓝光发射与强红光发射;同时对这种ZnO微棒的生长机理进行了探讨。     

ZnO纳米环的可控合成

以六次甲基四胺(Hexamethylenetetramine, C6H12N4)和水合硝酸锌[Zn(NO3)2·2H2O]为原料, 表面活性剂聚丙烯酰胺-氯化二烯丙基二甲基铵[poly(acrylamide-co-diallyldimethylammonium chloride, 缩写为PAM-CTAC]为形貌控制剂, 采用液相沉淀法合成了ZnO纳米环. 产物的结构与形貌经X射线粉末衍射(XRD)和扫描电子显微镜(SEM)表征. 研究了不同实验条件(如表面活性剂的浓度、反应物浓度、反应温度和反应时间等)对产物形貌与尺寸的影响. 讨论了PAM-CTAC作用下ZnO纳米环可能的形成机理. 结果表明, 合成产物为六方Wurtzite型结构的ZnO纳米环, 环内径约为220 nm, 壁厚约为70 nm. 反应物浓度、反应温度对ZnO纳米环的形成以及纳米环的尺寸都有一定的影响, 但起关键作用的是PAM-CTAC. 通过改变PAM-CTAC的浓度, 能有效地实现ZnO纳米环的可控合成. 室温荧光光谱显示, ZnO纳米环的紫外发射峰具有较窄的半高宽(FWHM)(约7 nm), 表明合成产物具有较窄的尺寸分布.     

化学溶液沉积法制备单分散氧化锌纳米棒阵列

在由溶胶凝胶法制备的纳米ZnO薄膜基底上, 采用化学溶液沉积法制备了单分散、高度取向的ZnO纳米棒阵列膜. 通过控制纳米ZnO薄膜的制备工艺, 可以调节氧化锌纳米棒的直径. 利用FESEM, TEM, HRTEM, SAED和XRD表征了氧化锌纳米棒阵列的形貌和晶体结构. ZnO纳米棒的室温PL谱具有很高的紫外带边发射峰, 在可见光波段无发射峰, 表明该方法制备的ZnO纳米棒晶体结构完整, 晶体中O空位的浓度很低.     

微波诱导燃烧法合成类花状ZnO纳米材料及其晶体结构、荧光性质研究

以硝酸锌[Zn(NO3)2.6H2O]和尿素[CO(NH2)2]作前驱体,通过微波诱导燃烧技术可控合成具有不同形貌的ZnO纳米晶体,并用热重分析和差热分析进行了研究。对各种生长条件:微波功率,辐射时间和尿素/Zn2+物质的量的比对ZnO纳米晶体形貌的影响作了分析。结果表明:尿素/Zn2+物质的量的比对ZnO纳米材料的形貌具有显著影响。X衍射图表明合成的ZnO纳米结构呈六角形。傅里叶变换红外光谱图中400~500 cm-1处明显的峰为Zn-O的振动峰。ZnO纳米结构的发光光谱在366 nm的带边发射,因缺陷又由许多可见光发射峰组成。用扫描电子显微镜、透射电子显微镜、选区电子衍射研究了花状ZnO纳米结构的增长机理。本方法仅需几分钟就获得的了ZnO纳米结构。     

双盘状ZnO的可控制备

采用水热法制备了形貌可控、 尺寸均一的双盘状ZnO. X射线粉末衍射(XRD)、 扫描电子显微镜(SEM)及透射电子显微镜(TEM)等测试结果表明, 制备的ZnO具有六方纤锌矿结构, 由2个直径约为4 μm, 厚度约为600 nm的圆盘复合而成. 考察了反应温度和乙酸锌与柠檬酸钾的摩尔比对产物形貌与尺寸的影响, 实现了双盘状ZnO的可控合成, 并初步探讨了其形成机理. 荧光光谱显示, 双盘状ZnO的紫外发射峰半高宽约为10 nm, 比块体ZnO的紫外发射峰半高宽(18 nm)窄, 表明双盘状ZnO具有更好的光学特性.     

Ag掺杂对n-ZnO纳米棒/p-GaN异质结结构和发光性能的影响

利用简单的水热合成法在p-GaN薄膜上制备了Ag掺杂的一维ZnO纳米棒(ZnO NRs),并且研究了Ag掺杂对于ZnO NRs结构和形貌以及n-ZnO NRs/p-GaN异质结发光特性的影响。结果表明,不同Ag掺杂浓度的ZnO纳米棒截面均呈六边形的棒状结构,且纳米棒的取向垂直于衬底;XRD分析结果表明,随着Ag掺杂浓度的增加,ZnO纳米棒(0002)晶面的峰位向衍射角减小的方向移动,表明Ag+置换了ZnO晶格中的部分Zn2+后使其晶格常数略增加;随着Ag掺杂浓度的增加,ZnO纳米棒近带边发光峰发生一定的红移并且强度逐渐减弱,黄带发光峰逐渐增强,n-ZnO NRs/p-GaN异质结具有更好的传输效率。     

Ag掺杂对n-ZnO纳米棒/p-GaN异质结结构和发光性能的影响

利用简单的水热合成法在p-GaN薄膜上制备了Ag掺杂的一维ZnO纳米棒（ZnO NRs）,并且研究了Ag掺杂对于ZnO NRs结构和形貌以及n-ZnO NRs/p-GaN异质结发光特性的影响。结果表明,不同Ag掺杂浓度的ZnO纳米棒截面均呈六边形的棒状结构,且纳米棒的取向垂直于衬底;XRD分析结果表明,随着Ag掺杂浓度的增加,ZnO纳米棒（0002）晶面的峰位向衍射角减小的方向移动,表明Ag⁺置换了ZnO晶格中的部分Zn²⁺后使其晶格常数略增加;随着Ag掺杂浓度的增加,ZnO纳米棒近带边发光峰发生一定的红移并且强度逐渐减弱,黄带发光峰逐渐增强,n-ZnO NRs/p-GaN异质结具有更好的传输效率。     

Soft template synthesis of ZnO nanorods and their optical properties

A simple solution route was developed to fabricate monodisperse wurtzite ZnO nanorods. The as-prepared samples were 5 ??m in length and 70?C100 nm in diameter. The crystallinity, morphology, and structure of the rod-like ZnO microcrystals were examined. The crystal phases and the microstructure of the nanorods were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Room- and low-temperature photoluminescence (PL) and Raman spectra were employed to investigate the surface states of the samples. The deep-level emission band was barely observable at both room and cryogenic temperatures.     

Preparation,characterization and photocatalytic properties of BiOBr/ZnO composites

BiOBr/ZnO composite photocatalysts were prepared by a simple hydrothermal method. The as-prepared samples were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), high-resolution transmission electron microscopy(HRTEM), UV–Vis diffusion reflectance spectroscopy(DRS) and photoluminescence(PL) spectroscopy, respectively. The photocatalytic activities were evaluated by the degradation of methyl blue(MB) under the simulated sunlight irradiation. Among all the samples, the BiOBr/ZnO composite with a mole ratio of 3:1(Bi:Zn) exhibited the best photocatalytic activity. The improvement of photocatalytic activity was mainly attributed to the low recombination ratio of photo-induced electron-hole pairs. The possible photocatalytic mechanism was discussed on the basis of the band structures of BiOBr and ZnO.     

Synthesis of morphological ZnO particles by a facile solution-based chemical method

In this study, a facile solution-based chemical method has been developed to produce ZnO particles in the presence of triethanolamine (TEA) and NaOH. In this novel method, TEA acted as complexing reagents, and NaOH contributed to the transformation of ZnO precursor (Zn–TEA complex) into ZnO particles. The core of this new strategy is to transform Zn–TEA complex into morphological ZnO particles directly by a facile solution method. The results from transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM) analysis revealed that the morphologies of the as-prepared ZnO samples evolved from slices to quasi-spheres by increasing the amount of TEA. X-ray diffraction (XRD), Raman and room-temperature photoluminescence (PL) tests showed that these ZnO samples had wurtzite structures. A reasonable mechanism for the transformation of Zn–TEA complex into morphological ZnO particles was supplied.     

三维花状ZnO纳米材料的制备及发光性质

常压下用溶胶凝胶和化学溶液生长两步法在3种不同的衬底上制备出三维花状ZnO纳米材料.采用X射线衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)、选区电子衍射(SAED)、紫外吸收(UV)光谱和光致发光光谱(PL)对样品进行分析,结果表明,花状ZnO的组成单元为沿c轴方向生长的ZnO纳米棒,直径约为100 nm,...     

Polyvinylpyrrolidone-assisted growth and optical properties of ZnO hexagonal bilayer disk-like microstructures

ZnO hexagonal bilayer disk-like microstructures are successfully prepared assisted with polyvinylpyrrolidone (PVP), and the photoluminescence (PL) spectrum of as-prepared ZnO samples showed a very strong ultraviolet (UV) emission at the UV region.     

Synthesis and characterization of ZnO nanowires by thermal oxidation of Zn thin films at various temperatures

In this research high-quality zinc oxide (ZnO) nanowires have been synthesized by thermal oxidation of metallic Zn thin films. Metallic Zn films with thicknesses of 250 nm have been deposited on a glass substrate by the PVD technique. The deposited zinc thin films were oxidized in air at various temperatures ranging between 450 °C to 650 °C. Surface morphology, structural and optical properties of the ZnO nanowires were examined by scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) and photoluminescence (PL) measurements. XRD analysis demonstrated that the ZnO nanowires has a wurtzite structure with orientation of (002), and the nanowires prepared at 600 °C has a better crystalline quality than samples prepared at other temperatures. SEM results indicate that by increasing the oxidation temperature, the dimensions of the ZnO nanowires increase. The optimum temperature for synthesizing high density, ZnO nanowires was determined to be 600 °C. EDX results revealed that only Zn and O are present in the samples, indicating a pure ZnO composition. The PL spectra of as-synthesized nanowires exhibited a strong UV emission and a relatively weak green emission.     

Optical properties of ZnO and ZnO:In nanorods assembled by sol-gel method

Self-assembled zinc oxide (ZnO) and indium-doping zinc oxide (ZnO:In) nanorod thin films were synthesized on quartz substrates without catalyst in aqueous solution by sol-gel method. The samples were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), Raman-scattering spectroscopy, room-temperature photoluminescence (PL) spectra, and temperature-dependent PL spectra measurements. XRD and Raman spectra illustrated that there were no single In2O3 phase in ZnO lattice after indium doping. The PL spectra of ZnO showed a strong UV emission band located at 394 nm and a very weak visible emission associated with deep-level defects. Indium incorporation induced the shift of optical band gap, quenching of the near-band-edge photoluminescence and enhanced LO mode multiphonon resonant Raman scattering in ZnO crystals at different temperatures. Abnormal temperature dependence of UV emission integrated intensity of ZnO and ZnO:In samples is observed. The local state emission peak of ZnO:In samples at 3.37 eV is observed in low-temperature PL spectra. The near-band-edge emission peak at room temperature was a mixture of excitons and impurity-related transitions for both of two samples.     

ZnO/Ag微米球的合成与光催化性能

用微波辅助多元醇法对预先制备的ZnO微米球进行修饰,合成了载银氧化锌微米球（ZnO/Ag）. 利用X射线衍射仪、场发射扫描电子显微镜、透射电子显微镜、X射线光电子能谱仪、紫外-可见双光束分光光度计和光致发光光谱仪等对样品的结构、形貌和光学性能进行了表征. 在紫外光照射下,通过亚甲基蓝的降解反应研究了样品的光催化活性. 结果表明,所制备的ZnO/Ag微米球是由面心立方的Ag纳米颗粒附着在纤锌矿结构的ZnO球表面形成;与ZnO相比,ZnO/Ag的紫外-可见光吸收光谱发生明显红移,在紫外和可见光范围均有较强的吸收;随着Ag含量的增加,ZnO/Ag荧光光谱强度先减弱后增强;与ZnO相比,ZnO/Ag的光催化活性明显提高,AgNO₃ 浓度为0.05 mol/L时制得的ZnO/Ag光催化活性最高.     

液相法制备取向ZnO纳米线阵列的场发射特性(英文)

采用水热合成工艺,在不同条件下制备了不同的一维取向ZnO纳米线阵列样品.用X射线衍射仪(XRD)、扫描电镜(SEM)及透射电镜(TEM)对样品的晶体结构和形貌等进行了表征,对样品的场发射特性进行了分析和比较,并用Fowler-Nordheim方程对影响ZnO纳米线场发射的因素进行了研究.结果表明,具有较低生长密度分布、较高的长径比和较尖锐生长端的ZnO纳米线阵列样品具有较好的场发射特性.     

Controlled Synthesis of Sea-urchin-like ZnO Nanomaterials with the Aid of Ethylene Glycol Using a Solvothermal Method

Sea-urchin-like ZnO nanomaterials were successfully synthesized by decomposition of zinc acetate precursor in the presence of sodium hydroxide and ethylene glycol(EG) in an ethanol solution using a solvothermal method at 180 ℃ for 12 h.The crystalline phase and morphology of the resultant nanomaterials were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),selected-area electronic diffraction(SAED) and high-resolution electron microscopy(HRTEM).Interestingly,the sizes and prod length of the samples can be easily tuned by changing the amount of directing agent EG and keeping other reaction conditions unchangeable.On the basis of our experimental outcomes,EG-controlled-nucleation-growth formation mechanism was proposed to correspond for the sea-urchin-like ZnO growth processes.And the photoluminescence(PL) spectra of the as-selected samples were measured at room temperature,presenting two emission peaks centered at～388 and 480 nm.