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Porous films with very large internal surface area offer a number of intriguing features which have been exploited for the design of optoelectronic devices[5].
Results and discussion Growth of ZnO nanowhiskers on FTO substrate Fig. 1 shows XRD patterns of ZnO nanowhiskers formed on the FTO substrate with textured ZnO-seed layer (No ZnO diffraction peaks were detected to ZnO seeds layer by XRD due to the small amount.).
All the diffraction peaks are in good agreement with the JCPDS card (36-1451) for the typical wurtzite-type ZnO crystal (hexagonal, P63mc).
ZnO nanowhiskers just showed a non-polar plane.
In this study, PEI, as an additive, contains a large number of amino groups in the long molecular chain, which could preferentially adsorb at different crystal faces and modify the surface free energy and growth rate [9].

The formation of ZnO nanostructures (NSs) were characterized by XRD, SEM, UV-vis.
All the diffraction peaks were well indexed to pure hexagonal Wurtzite ZnO (JCPDS card no. 80-0075) with space group P63 mc (no. 186) having the lattice parameters a = 3.252(3) (Å), c = 5.208(6) (Å).
The percentage of scavenging capacity by ZnO NPs was up to 92 %.
The antioxidant activities of ZnO NPs were attributed to crystallite size.
The amount of catalyst used is directly related to number of active sites in the reaction mixture.

CHINA xpzou2005@gmail.com Keywords: ZnO nanomaterials; hydrothermal growth; solution concentration Abstract.
SEM, XRD were utilized to characterize morphologies and crystal structures of ZnO.
The morphologies of ZnO nanostructures include tubes, wires, rods, belts, rings, flowers and flakes.
In addition to the base outside the diffraction peak ITO, other diffraction peak can match with wurtzite structure of ZnO（JCPDS card number 76-704）, so can prove product is zinc oxide.
When the solution concentration reduced, ZnO nanorods also self-assemble into flower structure.

Microwave assisted method on the morphology of aluminium doped ZnO nanocrystals P.
Microwave assisted heating generates heat to activate the formation of ZnO.
All diffraction peaks fitted very well to JCPDS card #36-1451.
Table 1 BET data for 1 at% aluminium doped and 4 at% aluminium doped ZnO synthesized by microwave irradiation for 10 min at 160 W and 640 W, respectively Acknowledgements The authors would like to thank Department of Materials Science and Engineering, Silpakorn University, Silpakorn University Research and Development Institute and Office of the Higher Education Commission under contract number SURDI_MUA 54/01/02 for financial support.
Pang, Rapid synthesis of ZnO micro/nanostructures in large scale.

Aminopropyltriethoxysilane(APTES)　was selected to modify commercial ZnO nanoparticles by bonding with hydroxyl group of ZnO.
ZnO nanorods; b.modified ZnO nanorods; c.ZnO nanoparticles; d. modified ZnO nanoparticles) Fig. 2 shows the TEM images of ZnO nanocrystals with or without surface modification.
However, it could be seen a large number of ZnO agglomerative nanoparticles.
ZnO nanorods, b. modified ZnO nanorods, c.
It could be seen from fig. 3 that all the diffraction peaks can be indexed as the hexagonal ZnO, consistent with the values in the standard card (JCPDS 36-1451).

Finally, both of the samples were heated at 1150ᵒC for 3 minutes to dissociate ZnO2 into ZnO particles and to remove the by- products of ZnO.
The peak position and the peak intensity is in good agreement with the data based on JCPDS card No. 01-070-8070.
Zn (OH)2 + 2OH-→ ZnO22-+ 2H2O (3) ZnO2 2-+ 2H2O → ZnO (4) The high supersaturation of Zn2+ and OH- will yield ZnO22- precipitate whereby a large number of ZnO22- nuclei or particles will be produces until the supersaturation is depleted.
Conclusion In conclusion, ZnO microsphere with feeler like structure has been observed for ZnO sample without the utilization of iodine whereas ZnO spherical particles are observed for sample with the presence of iodine.
Thus, the inclusion of iodine ion in ZnO growth process has shown to have significant effect on the morphology, structural and optical properties of ZnO.

Experimental Details Two commercial grades of ZnO powder were obtained from the Approfit ZnO Mfg Co.
The observed lattice values agree with the hexagonal phase of ZnO (JCPDS card 36-1451).
Antibacterial activity of ZnO powder grades.
For the White ZnO sample, however, inhibition is only seen in 15 mM concentration (35%) and 20 mM (70%) that are lower than that of Pharma ZnO sample.
A number of studies have suggested, two mechanisms for the interaction between ZnO and bacteria that are (i) the production of increased levels of ROS, mostly hydroxyl radicals and singlet oxygen [10], and (ii) deposition of the ZnO on the surface of bacteria or gathering of ZnO either in the cytoplasm or in the periplasmic region causing disruption of cellular function and/or disruption and disorganization of membranes [11].

Synthesis of ZnO nanorods.
Results and discussion Figure 1(a, b) represents FTIR spectra of ZnO and ZnO/SiO2 core-shell nanorods.
Different vibrational modes for ZnO and silica coated ZnO are compared in Table 1.
Except for the broad peak around 23°, all the other visible diffraction peaks in the pattern can be well indexed to the wurtzite ZnO (hexagonal crystal system, P63 mc space group, JCPDS card No. 36-1451).
These two wave numbers (nm) were identified by finding the point of inflexion between high transmittance and high absorption and can be termed absorption edges.

Many semiconductors such as TiO2, CdS, WO3, Fe2O3, ZnS, and ZnO are used in photocatalysis [1] being ZnO and TiO2 the most used.
Results and discussion Structural properties The XRD patterns of the ZnO and ZnO@Cr powders showed only a set of diffraction lines ascribed to the wurtzite structure, which was identified from JCPDS card number 36-14-51.
Crystallographic data of ZnO and ZnO@Cr powders for each coating.
Crystallite size and lattice microstrain of the ZnO powder and ZnO@Cr powder for each coat.
The scanning electron microscopy (SEM) for the ZnO powder and the ZnO@Cr powders obtained for each coating is show in Fig. 2.

The ZnO seed layer was deposited on substrate to promote growth of ZnO nanorods.
ZnO is a direct wide bandgap material with a bandgap of 3.4 eV.
As shown in Fig. 3(a), the number of rods produced at 60oC is very little that indicate not enough energy to promote the formation of nanorods from the seed at this condition.
Fig. 6 shows the XRD patterns of ZnO nanorods.
All the peaks are indexed to typical wurtzite ZnO, with calculated cell parameter a=3.25A and c=5.19A, consistent with the standard value for ZnO (JCPDS card no. 036-1451) [25].