Search results

To overcome this problem, numerous experiments have been performed to fabricate superhydrophobic woods surfaces via a number of different approaches.
In this regard, ZnO/wood hybrid materials are investigated here.
After that, a transparent and stable ZnO colloid was thus obtained.
The XRD diffraction peaks of the hydrothermally treated wood shown in Fig. 1B are well indexed to the standard diffraction pattern of hexagonal phase ZnO (Fig. 1C; JCPDS card No. 36-1451), which suggests a wurtzite structured ZnO with high crystallinity covered onto the wood surface.
XRD patterns of: (A) the pristine wood; (B) the hydrothermally treated wood; (C) standard ZnO (JCPDS card No. 36-1451) Fig. 2a shows the SEM image of the tangential section of the pristine wood.

Table 2: The average diameter and roughness of ZnO:Cu2O NPs prepared under different number of pulses.
Cu2O peaks were centered at 2θ= 37, 43, 64 and 77 which corresponds to (111), (200), (220) and (222) planes similar to the JCPDS card No. 78-2076 [13].
ZnO peaks were centered at 2θ=32, 34, 56 and 63 with (100), (002), (110) and (103) planes same as in JCPDS card No. 79-0208 [14].
(a) (b) Figure 3: ZnO:Cu2O (a) absorption spectrum, (b) Energy gap at E=900 mJ, different number of pulses.
Conclusion Nd:YAG laser was used at different number of shots to prepare ZnO:Cu2O nanoparticles.

Many coupled semiconductor systems, such as ZnO-WO3 [7], ZnO-Fe2O3 [8], NiO-ZnO [9] and TiO2-ZnO [10] were used.
As shown in Fig. 1, the diffraction peaks at 2θ= 31.88◦, 34.41◦, 36.26◦, 47.52◦ and 56.62◦ are attributed to the typical wurtzite structure of ZnO (JCPDS Card No. 36-1451), and the diffraction peaks at 2θ= 35.5◦ and 38.7◦ are assigned to the (0 0 2) and (1 1 1) planes of CuO (JCPDS Card No. 80-1917), respectively.
It can be seen that the number of CuO nanoparticles increases with increasing Cu/Zn molar ratio.
Fig. 2 SEM image of the as-prepared samples: (a) ZnO, (b) CuO (at. 4%)/ZnO, (c) CuO (at. 12.5%)/ZnO.
When further increasing Cu/Zn molar ratio, some CuO nanoparticles exist in the form of agglomerates, subsequently the number of p-n junctions between CuO and ZnO will decrease.

CuO/ZnO/SiNWs shows diffraction peaks at 31.44 (1 1 0), 53.3 (0 2 0) and 58.5 (2 0 2) reveals that the presence of Cu species on ZnO-SiNWs is mainly CuO phase [JCPDS card no. 89-5896].
Further that there is no change in wurtzite structure of ZnO morphology, which is confirmed from the observed 2θ values at 31.86 (1 0 0), 34.17 (0 0 2), 56.57(1 1 0) [JCPDS card no.36-1451].
In addition, the corresponding lattice parameters for the ZnO component in the coupled system deviate from the standard values [JCPDS card no. 36-1451, a = 0.326 nm, c = 0.522 nm].
Fig. 4(c)The calculated value of k for the 5:95 (CuO:ZnO) CuO/ZnO /SiNWs (k = 3.6×10−2 min−1) sample was almost four times higher than 10:90 (CuO:ZnO) CuO/ZnO /SiNWs (k=0.8×10−2 min−1) and almost eight times higher than 50:50 (CuO:ZnO) CuO/ZnO / SiNWs samples (k=0.4×10−2 min−1).
The reason for such enhanced rate constant is due to the generation of enhanced number of surface active radicals by reaction between electron acceptors and CuO/ZnO/SiNWs.

Fig.1 shows the typical XRD pattern of the synthesized ZnO nanorods.
As is evident, all the peaks can be indexed to the hexagonal wurtzite structure of ZnO according to the values in the JCPDS(card no. 36-1451) data card.
Fig. 1 XRD pattern of the nano-size ZnO Fig. 2 TEM pattern of the nano-size ZnO TEM Analysis.
Fig.2 shows the TEM image of the nano-size ZnO, which is clearly rod conglomerates.The width and the length of ZnO nanorods are 20-30nm and 500-600nm respectively.
In the meantime, the higher the concentration of RhB, the less the transmissivity of the ultraviolet and the number of the quantum photon participated in the photocatalysis reaction.

The remarkable effects of anions on ZnO can be ascribed to the adsorption of the anions on the surface of ZnO, which hinders the further growth of ZnO nuclei.
In Fig. 1(a, b, c), all the diffraction peaks can be indexed to wurtzite ZnO with lattice constants of a=3.24 Å and c=5.19 Å, which is in good agreement with the literature values (JCPDS card number 36-1451).
However, the XRD spectrum exhibits same characteristic peak profile as the Zn4SO4(OH)6·4H2O (JCPDS card number 44-0673), which confirms the formation of basic zinc sulfate.
The anions has remarkable effects on the morphologies of ZnO, which can be ascribed to the adsorption of the anion on the surface of ZnO [18].
The remarkable effects of anions on ZnO can be ascribed to the adsorption of the anions on the surface of ZnO, which hinders the further growth of ZnO nuclei.

Then ZnO nanorods and ZnO nanosheets can be obtained by calcined procuesors at 300°C.
All diffraction peaks can be indexed to the hexagonal wurtzite structure ZnO and diffraction date were in agreement with JCPDS card of ZnO (JCPDS 36-1451).
No peeks other than ZnO were detected.
It clearly reveals that the product is primarily composed of nanorods with mean diameters of about 80 nm and lengths of 100-400 nm, indicating that ZnO nanorods can be obtained by this method though a small number of nanoparticles were observed. .
Then ZnO nanorods and ZnO nanosheets can be obtained by calcined procuesors at 300°C.

Experimental Preparing of ZnO powders.
(a)500; (b)4K; (c)10K; (d)20K Fig.2 XRD patterns of ZnO powders (a) and corresponding JCPDS card data (b).
Results and Discussion As shown in Fig.1, a large number of sphere-like ZnO powders are observed with about 5 mm in diameter The micro-spheres are made up of nano-petals connecting with each other (Fig.1d).
There are 5 peaks with 2q of 31.9, 34.5, 36.7, 47.4 and 57.6 indicated by , (0002), , and according to JCPDS Card (No.36-1451), respectively.
(a-b) ZnO powders before modification; (b) placed upside down; (c-f) ZnO powders after modification; (c) ODS; (d) HDS; (e) DDS; (f) FAS.

Pure ZnO diffraction peaks match well with those given by the JCPDS card No.36-1451 for the hexagonal wurtzite structure.
The SnO2-ZnO nanofibers are in the polycrystalline structure with two phases of tetragonal rutile SnO2 (JCPDS 41-1445) and hexagonal wurtzite ZnO (JCPDS 36-1451) structure.
Fig. 1 (a) XRD patterns of pure ZnO and SnO2-ZnO nanofibers, (b) EDS spectroscopy of SnO2-ZnO nanofibers.
In particular, the charge transfer contributes to the enhancement of surface reactions which are proportional to the number of available electrons.
Acknowledgement This work was supported by Shanghai Leading Academic Discipline Project, (Project Number: B604), Foundation of He’nan Educational Committee (No. 2009A150001), Foundation of He’nan Science and Technology Committee (No. 092102210404).

The crystalline diffraction lines observed for the C/ZnO composite correspond to ZnO phase with hexagonal symmetry and space group P63mc (JCPDS 36-14-51 card) [13].
For the C/TiO2 composite, the diffraction lines observed are attributed to the TiO2 anatase with tetragonal symmetry and space group I41/amd (JCPDS 22-1272 card) [13].
FTIR spectra for: a) ZnO and TiO2, b) C/amorphous, C/ZnO and C/TiO2.
[13] JCPDS – International Centre for Diffraction Data.
Copyright© JCPDS-ICDD. 2000