ZnO nanorods

Alammar T, Mudring AV (2009) Facile ultrasound-assisted synthesis of ZnO nanorods in an ionic liquid. Mater Lett 63 732-735... 

Figure4.8 SEM cross-section (a) and top surface (b) images of lollipop-like V205-Zn0 core-shell structures. The top heads are V2O5 crystal balls and the stems are ZnO nanorods. Reprinted from [117] (2010) American Chemical Society.

Figure 10.13. (a) SEM image of ZnO nanorods coated with octylamine. Scale bar, 200 nm. (b) Uniform nanorod film fabricated by spin coating of ZnO nanorods. Scale bar, 500 nm. The nanorods assemble into domains with nematic ordering, (c) Saturated transfer characteristics for a thin-film transistor fabricated by spin coating of ZnO nanorods with different ligands octylamine (solid line), butylamine (dashed line). Vi = 60V. (d) Output characteristics of a spin-coated device made from octylamine-stabilized ZnO nanorods.The device structure is shown in the inset in (c). Reproduced from Ref. 83, Copyright 2006, with permission from the American Chemical Society. 

Sun, B. Sirringhaus, H. 2006. Surface tension and fluid flow driven self-assembly of ordered ZnO nanorod films for high-performance field effect transistors. /. Am. Chem. Soc. 128 16231-16237. 

Harnack, O. Pacholski, C. Weller, H. Yasuda, A. Wessels, J. M. 2003. Rectifying behavior of electrically aligned ZnO nanorods. Nano Lett. 3 1097-1101. 

Figure 14.3. Cross-sectional SEM of a ZnO nanorod carpet grown on fluorine-doped Sn02 by solution growth.16 Scale bar is 100 nm. 

In conclusion, nanorods are a potentially interesting material, but present results still do not allow understanding of whether the nanostructure leads to an improvement of the intrinsic photocatalytic behaviour, or whether other factors (accessible surface area, enhanced adsorption, etc) are responsible for the observed differences. In ZnO nanorods have been shown quite recently by surface photovoltage spectroscopy that the built-in electrical field is the main driving force for the separation of the photogenerated electron-hole pairs.191 This indicates that the nano-order influences the photophysical surface processes after photogeneration of the electron-hole pairs. A similar effect could be expected for Titania nanorods. However, present data do not support this suggestion, mainly due to the absence of adequate photo-physical and -chemical characterization of the materials and surface processes. 

Li Q, Kumar V, Li Y, Zhang H, Marks TJ, Chang RPH (2005) Fabrication of ZnO nanorods and nanotubes in aqueous solutions. Chem Mater 17 1001-1006... 

Patterned nanorod arrays of Ti02 for photonic applications could be produced by coating patterned and aligned ZnO nanorod arrays. 

Yin Z, Wu S, Zhou X et al (2010) Electrochemical deposition of ZnO nanorods on transparent reduced graphene oxide electrodes for hybrid solar cells. Small 6 307-312... 

Ishizumi and Kanemitsu (2005) have studied PL properties of Eu3+ doped ZnO nanorods fabricated by a microemulsion method. The PL of bound exciton recombination and ZnO defects was observed near 370 and 650 nm under 325-nm light excitation, but no emission of Eu3+ occurred. On the other hand, the sharp PL peaks due to the intra-4f transitions of Eu3+ ions appeared under nonresonant excitation below the band-gap energy of ZnO (454 and 457.9 nm) in addition to direct excitation to 5D2 (465.8 nm). Therefore the authors concluded that the energy transfer occurs from the ZnO nanorods to Eu3+ ions through ZnO-defect states. This energy transfer mechanism seems very different from the previous one and more spectroscopic evidence is required to confirm it. 

A seed-assisted chemical reaction at 368 K is found to yield uniform, straight, thin single-crystalline ZnO nanorods on a hectogram scale,181 Zinc oxide nanowires have been synthesized in large quantities using plasma synthesis.1 Variable-aspect-ratio,... 

Growth Kinetics of ZnO Nanorods Capping-Dependent Mechanism and Other Interesting Features... 

Synthesis of ZnO Nanorods. In order to carry out the growth study in the absence of any capping agent, ZnO nanorods were prepared by the reaction of zinc acetate dihydrate (Zn(CH3-C00)2 2H20) and sodium hydroxide in ethanol at 100 °C under solvothermal conditions. The reaction was stopped at different times (I, 2, 3, 6, 12, 18, and 24 h), and the products were analyzed by TEM and SAXS. In a typical synthesis, Zn(CH3-... 

Figure 2. Time evolution of the length distributions of the uncapped (blue) and the PVP-capped (black) ZnO nanorods obtained from TEM images.

Figure 3. SAXS data of (a) uncapped and (b) PVP-capped ZnO nanorods obtained after different times of reaction. Solid lines are the model fits to the experimental data.

Figure 5. Time evolution of the (a) average diameter ((D)) and (b) aspect ratio of the uncapped ZnO nanorods obtained from TEM and SAXS.

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