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As a result, the pure ZnO nanofibers were obtained.
But in Fig. 2(d), the number of the fibers decreased and the diameter of the composite fibers increased.
All the peaks agreed well with the JCPDS card (No.89-1397), that conforming the formation of pure ZnO phase after the calcination.
Fig.3 XRD pattern of calcined ZnO nanofibers(The inset was the standard XRD pattern of ZnO).
The XRD detection confirmed the typical ZnO constructions of ZnO nanofibers.

Further analyses also proved that, with the increased precursor concentrations, the number density of the ZnO nanorods was progressively increased along with the more complete hexagonal wurtzite structures.
Fig. 3(b) demonstrates a calculated number density of the ZnO nanorods per 100 mm2 with respect to the utilized precursor concentration.
This limitation thus resulted in a nearly constant diameter size (Zone II) on the ZnO nanorods prepared at high concentrations, although the number density was significantly increased.
mm2 Fig. 3 Plots of (a) average diameter and the length, and (b) number density of the ZnO nanorods with respect to the utilized precursor concentration. 5 mM 20 mM Fig.4 compares and contrasts the selected XRD patterns of the ZnO nanorods synthesized in the aqueous solution with the precursor concentration 5 and 20 mM.
From the figure, both samples were identified as polycrystalline, according to the JCPDS 76-0704 standard card.

Study on Preparation of Porous ZnO Microspheres and Photocatalytic Performance Leilei Qi School of Science, Sichuan University of Science & Engineering, China Keywords: ZnO; Porous microspheres; Solvothermal method; Nanometer material Abstract.
ZnO is the most abundant morphology in semiconductor materials for metal oxide, its photocatalytic performance dependent on the morphology and structure of ZnO, and has been reported to demonstrate a multi-level structure of ZnO micro nano materials that can exhibit better photocatalytic properties.
In order to establish the relationship of ZnO morphology and photocatalytic performance, still need to base a large number of experimental studies lay the foundation for the theory system.
As can be seen from the graph, all peaks match the peak of Zinc Carbonate Hydroxide on standard card (JCPDS 19-1458), the precursor with this method for the synthesis is Zinc Carbonate Hydroxide.
All peaks in B diagram (JPCDS 16-3451) is exactly the same as all peaks of Zinc Oxide Standard card, and did not detect other miscellaneous peak, that after firing, precursor into the Zinc Oxide.

The Influence of Mechanical Activation on the Stoichiometry and Defect Structure of a Sintered ZnO-Cr2O3 System Z.
The structure of spinel oxides is responsible for a variety of interesting physical and chemical properties exhibited by these compounds, since it can accommodate a very large number of different cations, some in more than one oxidation state, distributed in different ways among the A and B sites [4-6].
A wellcrystallized cubic spinel phase, ZnCr2O4, was clearly detected in all sintered samples due to the presence of diffraction lines indicated on the JCPDS cards 22-1107.
Also, small amounts of impurities such as unreacted ZnO (JCPDS cards 36-1451) and Cr2O3 (JCPDS cards 38-1479) were confirmed.
The amount of unreacted Cr2O3 is slightly greater than that of ZnO in the sintered sample ZC-00.

Heterostructure of Ag/ZnO was synthesized by a reduction of Tollen’s reagent on ZnO powders.
The efficiencies of dye degradations for all three dyes by Ag/ZnO are better than that of pure ZnO.
The diffraction peaks at 2q were at 38.03, 43.95 and 63.99, and these matched well with the (111), (200) and (220) plane, respectively, of a face-centered cubic structure for metallic Ag (JCPDS card number 04-0783).
The uv-vis spectra of ZnO and Ag/ZnO powders are presented in Fig 3.
Fig. 1 X-ray diffraction patterns of ZnO and Ag/ZnO powders Fig. 2 Transmission electron microscope image of Ag/ZnO powders Fig. 3 Absorption spectra of ZnO and Ag/ZnO powders Fig. 4 Comparative photocatalytic activities between ZnO and Ag/ZnO for degrading methylene blue (MB), rhodamine B (RhB) and reactive orange 16 (RO) dyes The comparative studies between the ZnO and the Ag/ZnO are shown in Fig 4.

Using soft template for controlling ZnO morphology, a stabilizer must be added during its synthesis and this increases the number of preparation steps.
All diffraction peaks matched well with the JCPDS card number 36-1451 so it can be concluded that all prepared ZnO solids crystallized in a hexagonal würtzite structure.
Photocatalytic efficiencies of ZnO Fig. 4.
At 1-3 mol% of Ag, the photocatalytic activity of Ag/ZnO was much better than pure ZnO as shown in Fig. 4, because the added Ag on the surface of the ZnO generated a new level that was below the conduction band (CB) of ZnO [9].
This could result from a reduction of light absorption by ZnO due to an overloading of the Ag coverage on the surface of the ZnO.

A small number of flower-like structures compared to the majority oval type structure suggest that secondary nucleation had occurred during the process of growth.
All of the high intensity peaks, including the strong (101) peak, are assigned to wurtzite ZnO hexagonal indicating that the product is pure ZnO.
The morphology of ZnO grown on the Si (100) is shown in Fig. 1(a).
XRD pattern of the ZnO nanostructured films is shown in Fig. 2.
All of the high intensity peaks can be indexed as hexagonal wurtzite structures of ZnO with lattice parameter of a = 3.24982 Å and c = 5.20661 Å (JCPDS Card No. 36-1451) indicating the product is pure.

The 2θ values obtained were compared to data files from the Joint Committee on Powder Diffraction Standards (JCPDS).
The hkl parameters of the CuO-ZnO thin film are determined using the JCPDS Card.
The XRD peaks match the reported diffraction pattern of CuO with a monoclinic structure (JCPDS card # 80-1917).
Similarly, diffraction peaks for ZnO having a hexagonal structure match well with the reported XRD pattern (JCPDS card # 36- 1451).
High porosity, voids, and trapezium-shaped grains are also available in large numbers, and a more effective surface area has been observed for oxygen species adsorption.

China a30300698@qq.com Keywords: ZnO nanorod arrays; Morphologies; Aqueous solutions; Low temperature Abstract. well-aligned ZnO nanorod arrays (ZNRAs) grown on the ZnO seed layers coated p-silicon (p-Si) substrates in various times from 1.5 to 5 hr have been fabricated from aqueous solutions at low temperature.
The XRD results showed that ZnO nanorods were wurtzite-structured (hexagonal) ZnO.
Up till now, a number of physical and chemical techniques such as the vapour liquid solid method [8], chemical vapour deposition [9], hydrothermal growth [10-13] and chemical bath deposition [15-17] were used to fabricate well-aligned ZNRAs or ZNWAs.
It can be noted that all of the diffraction peaks of ZnO nanorods can be indexed as those from the known wurtzite-structured (hexagonal) ZnO (JCPDS card No. 36-1451), the (002) diffraction peak of ZnO.nanorods displays a substantially greater intensity, further confirming that ZnO nanorods are much better aligned on a ZnO seeds-coated p-Si substrate and also that nanorods grow along (0001) direction.
The ZnO nanorods grew vertically from the substrates, having uniform thickness and length distribution.

Preparation of ZnO and ZnO/CS films.
Fig. 2 XRD patterns of (a) ZnO and (b) ZnO/CS films.
Fig.3 FT-IR spectra of (a) CS，(b)ZnO and (c) ZnO/CS films The phase and surface morphologies of ZnO and ZnO/CS films.
The ZnO film is highly crystalline, and all peaks matched well with the hexagonal structure of ZnO [JCPDS card No. 36-1451].
This process can be easily scaled up for industrial production and a large number of metal oxides/polyelectrolyte anticorrosion composite functional films can be fabricated by using this strategy.