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1.
Single crystalline ZnO nanorods with wurtzite structure have been prepared by a simple hydrothermal process. The microstructure and composition of the products were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM, energy dispersive X-ray spectrum (EDS) and Raman spectrum. The nanorods have diameters ranging from 100 nm to 800 nm and length of longer than 10 µm. Raman peak at 437.8 cm− 1 displays the characteristic peak of wurtzite ZnO. Photoluminescence (PL) spectrum shows a blue light emission at 441 nm, which is related to radiative recombination of photo-generated holes with singularly ionized oxygen vacancies.  相似文献   

2.
ZnO nanorods of 25 nm with quite homogeneous size and shape have been fabricated by introducing ZnO sols as nucleation centers prior to the hydrothermal reaction. The samples were characterized by scanning electron microscope, transmission electron microscope, X-ray diffraction, photoluminescence and resonant Raman spectra. After ZnO sols are introduced, the width of the resulting nanorods decreases above an order of magnitude and the aspect ratio increases 5 times. The increase of the intensity ratio of ultraviolet to visible emissions in room-temperature photoluminescence spectrum and the decrease of the Raman linewidths show the improvement in the quality of ZnO nanorods. Influences of the number of seed nuclei and the aging time of ZnO sols on the morphology of ZnO nanorods are discussed.  相似文献   

3.
The authors report the growth of single crystalline ZnO nanorods by direct current magnetron sputtering in the oblique angle deposition configuration near room temperature. These isolated nanorods have a diameter of  40 nm, an inter-rod spacing of  20 nm, and a height of  100 nm. The nanorods show a (002) orientation along the rod-axis which is normal to the substrate. The low temperature fabrication of single crystal ZnO nanorods may find potential applications in optoelectronics and energy conversion devices.  相似文献   

4.
ZnO纳米棒的低温湿化学制备   总被引:1,自引:1,他引:1  
刘秀兰  李佳  赵晓鹏 《功能材料》2005,36(4):636-638
在低温反应条件下,通过超声的方法,以DBS作为表面活性剂,制备了ZnO纳米棒。化学反应的低温条件由冰水浴提供,温度为0~5℃。扫描电子显微镜和光学显微镜观察表明,所制备的纳米棒形状均一,截面为六方型,直径100nm,长度1μm; X 射线衍射表征指出所得到的纳米棒为六方晶型。同时,我们也研究了反应温度、表面活性剂含量、超声、回流时间对ZnO纳米棒形貌的影响。与其它制备方法相比,低温与超声技术可以更为方便获得分布均一,长径比较小的ZnO纳米棒。  相似文献   

5.
利用高度有序的多孔氧化铝膜作为模板,使用简单的热蒸发Zn粉的方法,成功地制备出高度有序的ZnO纳米棒束,该方法克服了制备有序纳米结构通常需要的催化剂或复杂的合成过程.利用扫描电镜、透射电镜和X射线衍射研究了样品的形貌及其结构特性,其结果表明模板表面所制备的ZnO纳米棒具有更好的有序度和结晶质量,从而推断出模板表面有序ZnO纳米棒的形成应该同模板表面局域化负电荷的存在有关.同Si基片上所形成无序纳米棒的光致发光谱相比,模板表面所形成的有序ZnO纳米棒束具有更强的紫外峰,表明有序的ZnO纳米棒具有更好的结晶质量和光学特性.  相似文献   

6.
Cadmium sulfide nanoparticles (CNPs) sensitized zinc oxide nanorod arrays (ZNRs) were synthesized in the two step deposition process at relatively low temperature. The vertically aligned ZNRs were grown on the conducting glass substrates (FTO) using aqueous chemical method, followed by the deposition of CNPs at 70 °C using chemical bath deposition (CBD) technique. The samples were characterized by optical absorption, X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy (PL). Further, the photoelectrochemical (PEC) performance of ZNRs with and without CNPs sensitization was tested in Na2S-NaOH-S and Na2SO4 electrolyte, respectively. When the CNPs are coated on the ZNRs, the optical absorption is enhanced and band edge is shifted towards visible region (525 nm) as compared with ZNRs (375 nm). The sample sensitized with CNPs shows higher photoelectrochemical (PEC) performance with maximum short circuit current of (Isc) 2.60 mA/cm2.  相似文献   

7.
Simple and low cost solution synthesis method was used to synthesise ZnO nanorods. Dodecyl benzene sulfonate was used to control the growth process and monodispersed nanorods with diameters in the range of 25 to 44 nm were obtained. X-ray diffraction, transmission electron microscopy and high resolution transmission electron microscopy measurements demonstrate the structure and morphology of the products. Laser power- and temperature-dependent photoluminescence (PL) experiments confirm the good ultraviolet emission characteristics. Short exciton lifetime feature relevant to thin nanorods was examined by time-resolved PL. Good optical quality and the size characteristics of the obtained products are discussed.  相似文献   

8.
We report growth of ZnO nanorods by low temperature (<100°C) solution growth method. The substrates (Si, glass and fused Quartz) were seeded by pre-coating with ZnO nanoparticles (4–7 nm diameter) prepared by chemical precipitation route. Nanorods were grown on the seeded substrate in aqueous solution of Zinc Nitrate and Hexamethylenetetramine (HMT). The growth process lasts for up to 8 h and at the maximum time of growth, the nanorods have a width of ∼230–250 nm and length of ∼1.5–1.6 μm. The growth process after some initial growth (<2 h) preserves the aspect ratio and leads to about 90% texturing along the (002) direction. The growth of the nanorods was studied with time and observed growth data suggests a two-stage growth process. The nanorods have a well-defined hexagonal morphology and have a Wurtzite structure. The nanorods were characterized by different techniques and have a band gap of 3.25 eV.  相似文献   

9.
Well-aligned ZnO nanorod arrays have been synthesized by a simple hydrothermal method with polyvinyl alcohol as surfactant on F:SnO2 conductive glasses substrates. Visible violet photoluminescence has been observed at room temperature. A series of annealing treatments in different environments have been made in order to investigate the nature of these emissions. The violet emission shows no change after annealing in air, while shifts to the ultra-violet region after annealing in H2. It is concluded that the violet emission is due to VZn defect formed at the surface of the ZnO nanorods.  相似文献   

10.
Plasmonic field absorption enhancement (PFAE) of Ag nanoparticles (Ag NPs) periodic arrays in CdSe-quantum dot (QD) sensitized ZnO nanorods was numerically investigated by the three-dimensional finite difference time domain (FDTD). The Ag NPs with spherical morphology were found to have an optimum PFAE compared to other Ag NP morphologies such as cubic and pyramidal. The results also showed that PFAE intensity in CdSe-QD-sensitized ZnO nanorods is increased with the reduction of Ag NP diameter until 10 nm and decreases thereafter. Moreover, the optimum density of spherical Ag NPs for optimum PFAE was observed as 20%. PFAE in CdSe-QD-sensitized ZnO nanorods is improved with increasing space between ZnO nanorods until 180 nm and reduces thereafter. Finally, the results showed that PFAE of Ag NPs for the high distance between ZnO nanorods is dependent on radiation angle; while for the low distance between ZnO nanorods it is free of radiation angle.  相似文献   

11.
刘然  章婷  赵谡玲  徐征  张福俊  李远  宋林  徐叙瑢 《功能材料》2008,39(3):488-489,493
采用3种不同的方法在氧化铟锡玻璃衬底上沉积一层ZnO纳米晶薄膜,然后采用改进的水热法在制备有ZnO纳米晶薄膜的衬底上生长ZnO纳米棒,实现了纳米棒从无序到有序的生长.从XRD和SEM图可得,有序的纳米棒沿(002)择优取向,基本与衬底垂直,平均直径约为40nm.  相似文献   

12.
A simple and rapid method has been developed for the preparation of rod-like ZnO nanocrystals via ultrasonic irradiation. The as-synthesized ZnO nanocrystals were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). The ZnO nanorods had an average diameter of 15-70 nm that varied from the ultrasonic operation mode. The results showed that Zn powder played an important role in the synthesis of ZnO nanorods. Through adding a sulfur source in the reaction system, ZnO/ZnS nanocables and ZnS nanotubes could be obtained with continuous ultrasonic irradiation. The formation mechanism of ZnS nanotubes could be attributed to the Kirkendall effect.  相似文献   

13.
采用简单、低温的方法,在修饰过的Zn片上成功制备出具有高度取向的ZnO纳米棒阵列.用SEM、XRD和PL技术对制备出的ZnO纳米棒的结构和谱学特性进行了表征,并通过降解甲基橙溶液研究了其光催化活性.结果表明,ZnO纳米棒是六方钎锌矿晶,与基底垂直,具有沿(002)晶面择优生长的特征.统计结果显示,湿化学反应24h后90%以上的ZnO纳米棒直径为80~140nm,长度为4μm.在PL谱中观察到3个荧光发射带,中心波长分别位于386nm的紫带、524nm的绿带和450~500nm附近的蓝带.ZnO纳米棒的光催化反应为一级反应,表观速率常数与甲基橙的初始浓度有关.  相似文献   

14.
ZnO nanorods were produced by pulsed laser deposition (PLD). Drops of nanoparticle colloid (gold or silver) were placed on silica substrates to form growth nuclei. All nanoparticles were monocrystalline, with well-defined crystal surfaces and a negative electrical charge. The ZnO nanorods were produced in an off-axis PLD configuration at oxygen pressure of 5 Pa. The growth of the nanorods started from the nanoparticles in different directions, as one nanoparticle could become a nucleus for more than one nanorod. The low substrate temperature used indicates the absence of a catalyst during the growth of the nanorods. The diameters of the fabricated 1-D ZnO nanostructures were in the range of 50-120 nm and their length was determined by the deposition time.  相似文献   

15.
Thin films of ZnO of 20, 40,160 and 320 nm thickness were deposited on Si (100) substrates by rf-magnetron sputtering and then nanorods were grown on the seed layer at 95 °C for 2 h. The ZnO nanorods were synthesized in C6H12N4 and Zn (NO3)2·6H2O solution by a hydrothermal method and the effect of seed layer thickness on the alignment, diameter, density and growth rate of nanorods was studied.The results revealed that the alignment of nanorods depended on crystallinity, grain size and roughness frequency of the sputtered seed layer, so that, with increase of seed layer thickness, crystallinity improved. In addition the grain size increased and the roughness frequency decreased and hence alignment and diameter of nanorods increased.Finally, we present a model for the effect of seed layer thickness on the alignment and diameter of the nanorods.  相似文献   

16.
在较低温条件下,采用直流电沉积法在AAO模板中成功制备出了大面积生长均匀的单晶Ag蚋米棒阵列.利用扫描电子显微镜(SEM),能谱仪(EDS),透射电子显微镜(TEM),选区电子衍射(SAED)和XRD等分析手段对样品进行形貌表征及成分分析.结果表明,阵列中的Ag纳米棒尺寸均匀,保持着良好的平行度,直径接近200nm,与AAO模板的孔径大小相当,且可以通过控制沉积时间来实现对Ag纳米棒长度的控制.  相似文献   

17.
在Au点阵模板上磁控溅射ZnO薄膜,然后在O2气氛下1000℃退火制备了ZnO单晶堆垒纳米棒。采用扫描电子显微镜(SEM)、高分辨透射电子显微镜(HRTEM)、X射线衍射(XRD)和傅立叶变换红外(FTIR)光谱对样品进行分析。结果表明,ZnO纳米棒是由诸多单晶堆垒而成,每个单晶均为六方纤锌矿结构,纳米棒直径在100nm左右。初步探讨了ZnO单晶堆垒纳米棒可能的生长机理。  相似文献   

18.
采用水热法制备了ZnO和不同Cd掺杂浓度的ZnO:Cd纳米棒。通过x射线衍射仪、扫描电子显微镜、紫外-可见-近红外分光光度计和拉曼光谱对ZnO:Cd纳米棒的结构和光学特性进行了系统研究。结果显示,样品为一维纳米棒结构,Cd的掺杂可以减小ZnO纳米棒的晶粒尺寸和光学带隙。利用分光光度计检测ZnO:Cd纳米棒对偶氮结构染料(甲基橙溶液)的光催化降解效率,结果表明Cd掺杂可以改善ZnO的光催化性能,掺杂浓度为16%时ZnO:Cd纳米棒对甲基橙溶液的光催化降解效率最高。  相似文献   

19.
Cobalt-doped ZnO nanorods were successfully synthesized on Si/SiO2 substrate using RF-magnetron sputtering at room temperature. The undoped and Co-doped ZnO nanostructures were characterized by XRD, FE-SEM, AFM, and PL spectra. The results showed that Co2+ replaced Zn2+ in the ZnO lattice without changing the wurtzite structure. The ZnO structure became high crystallite and was gradually converted into nanorods without extra phases as increased cobalt doping levels to 3 at.% and 4 at.%. The as-synthesized nanorod arrays were dense and vertically grew on the substrate with lengths of approximately 341 and 382.3 nm for 3 at.% and 4 at.% CO, respectively. PL analysis revealed that the ultraviolet (UV) emission intensity decreased and exhibited a blue shift with increased Co atomic percentage. This result was consistent with the energy bandgap values (3.26–3.3 eV) obtained from UV–vis spectra. The IV characteristics revealed that the Shottky diodes based on Co-doped ZnO nanostructure with Pd electrodes have high barrier height (0.715–0.797 eV) and low saturation current (0.035–0.841 μA). The barrier height decreased after annealing the diodes at 500 °C for 2 h. To the best of our knowledge, Schottky diodes based on Co-doped ZnO nanorods prepared by RF-magnetron sputtering have not yet been reported.  相似文献   

20.
ZnO纳米棒水热法制备及其发光性能   总被引:1,自引:0,他引:1  
采用水热法在玻璃基底上成功制备出了ZnO纳米棒.用x射线衍射仪(xRD)和扫描电子显微镜(SEM)对ZnO纳米棒的晶体结构和表面形貌进行了表征,初步探讨了ZnO纳米棒的生长机理;同时对ZnO纳米棒的光致发光性能进行测量,分析了水热温度和反应时间对ZnO纳米棒光致发光性能的影响.结果表明:ZnO纳米棒呈现六方纤锌矿结构,具有沿(002)晶面择优生长特征;随着水热反应温度的升高,ZnO纳米棒的发光强度逐渐增强;随着反应时间的延长,ZnO纳米棒发光强度在1~3 h内增强,而在3~10 h反而减弱.  相似文献   

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