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91.
In this study, we grew zinc oxide (ZnO) nanowire arrays on paper substrates using a two-step growth strategy. In the first step, we formed single-crystalline ZnO nanoparticles of uniform size distribution (ca. 4 nm) as seeds for the hydrothermal growth of the ZnO nanowire arrays. After spin-coating of these seeds onto paper, we grew ZnO nanowire arrays conformally on these substrates. The crystal structure of a ZnO nanowire revealed that the nanowires were single-crystalline and had grown along the c axis. Further visualization through annular bright field scanning transmission electron microscopy revealed that the hydrothermally grown ZnO nanowires possessed Zn polarity. From photocatalytic activity measurements of the ZnO nanowire (NW) arrays on paper substrate, we extracted rate constants of 0.415, 0.244, 0.195, and 0.08 s-1 for the degradation of methylene blue at incident angles of 0°, 30°, 60°, and 75°, respectively; that is, the photocatalytic activity of these ZnO nanowire arrays was related to the cosine of the incident angle of the UV light. Accordingly, these materials have promising applications in the design of sterilization systems and light-harvesting devices. 相似文献
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Duan Li Elisângela Guzi de Moraes Peng Guo Ji Zou Junzhan Zhang Paolo Colombo 《Science and Technology of Advanced Materials》2014,15(4)
Silicon nitride foams were prepared by direct foaming and subsequent rapid sintering at 1600 °C. The intense thermal radiation generated under the pressureless spark plasma sintering condition facilitated necking of Si3N4 grains. The prepared foams possessed a porosity of ~80 vol% and a compressive strength of ~10 MPa, which required only ~30 min for the entire sintering processes. Rapid growth of one-dimensional SiC nanowires from the cell walls was also observed. Thermodynamic calculations indicated that the vapor–liquid–solid model is applicable to the formation of SiC nanowires under vacuum. 相似文献
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Xinhui Xia Changrong Zhu Jingshan Luo Zhiyuan Zeng Cao Guan Chin Fan Ng Hua Zhang Hong Jin Fan 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(4):766-773
Metal sulfides are an emerging class of high‐performance electrode materials for solar cells and electrochemical energy storage devices. Here, a facile and powerful method based on anion exchange reactions is reported to achieve metal sulfide nanoarrays through a topotactical transformation from their metal oxide and hydroxide pre‐forms. Demonstrations are made to CoS and NiS nanowires, nanowalls, and core‐branch nanotrees on carbon cloth and nickel foam substrates. The sulfide nanoarrays exhibit superior redox reactivity for electrochemical energy storage. The self‐supported CoS nanowire arrays are tested as the pseudo‐capacitor cathode, which demonstrate enhanced high‐rate specific capacities and better cycle life as compared to the powder counterparts. The outstanding electrochemical properties of the sulfide nanoarrays are a consequence of the preservation of the nanoarray architecture and rigid connection with the current collector after the anion exchange reactions. 相似文献
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Daijiro Nozaki Jens Kunstmann Felix Zörgiebel Sebastian Pregl Larysa Baraban Walter M. Weber Thomas Mikolajick Gianaurelio Cuniberti 《Nano Research》2014,7(3):380-389
For the development of ultra-sensitive electrical bio/chemical sensors based on nanowire field effect transistors (FETs), the influence of the ions in the solution on the electron transport has to be understood. For this purpose we establish a simulation platform for nanowire FETs in the liquid environment by implementing the modified Poisson-Boltzmann model into Landauer transport theory. We investigate the changes of the electric potential and the transport characteristics due to the ions. The reduction of sensitivity of the sensors due to the screening effect from the electrolyte could be successfully reproduced. We also fabricated silicon nanowire Schottky-barrier FETs and our model could capture the observed reduction of the current with increasing ionic concentration. This shows that our simulation platform can be used to interpret ongoing experiments, to design nanowire FETs, and it also gives insight into controversial issues such as whether ions in the buffer solution affect the transport characteristics or not. 相似文献
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Wenqing Li Lei Liao Xiangheng Xiao Xinyue Zhao Zhigao Dai Shishang Guo Wei Wu Ying Shi Jinxia Xu Feng Ren Changzhong Jiang 《Nano Research》2014,(11):1691-1698
In this paper, we report a method to change the threshold voltage of SnO2 and In2O3 nanowire transistors by Ga^+ ion irradiation. Unlike the results in earlier reports, the threshold voltages of SnO2 and In2O3 nanowire field-effect transistors (FETs) shift in the negative gate voltage direction after Ga^+ ion irradiation. Smaller threshold voltages, achieved by Ga^+ ion irradiation, are required for high-performance and low-voltage operation. The threshold voltage shift can be attributed to the degradation of surface defects caused by Ga+ ion irradiation. After irradiation, the current on/off ratio declines slightly, but is still close to -106. The results indicate that Ga^+ ion beam irradiation plays a vital role in improving the performance of oxide nanowire FETs. 相似文献
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结合离子交换-高温烧结法,由钛酸钠纳米线制备了TiO_2纳米线。通过XRD、Uv-vis漫反射和SEM等测试手段,探讨离子交换时间和高温烧结温度对制备TiO_2纳米线的影响,并以甲基橙为目标污染物测试其光催化性能。结果表明:离子交换时间越长越有利于钛酸纳米线的形成,离子交换48h时钛酸钠纳米线基本转换成为钛酸纳米线;过低的烧结温度不利于TiO_2纳米线的形成,烧结温度650℃时钛酸纳米线基本分解成为TiO_2纳米线;钛酸钠纳米线几乎没有光催化性能,而TiO_2纳米线具有很强的光催化性能。 相似文献