A new approach for synthesis of ZnO nanorod flowerets and subsequent pure free-standing ZnO nanorods

2019 ◽  
Vol 30 (1) ◽  
pp. 30-41 ◽  
Author(s):  
B. Bhushan ◽  
B.S. Murty ◽  
K. Mondal
2020 ◽  
Vol 20 (6) ◽  
pp. 3512-3518
Author(s):  
Saleh Khan ◽  
Xiao-He Liu ◽  
Xi Jiang ◽  
Qing-Yun Chen

Highly efficient and effective porous ZnO nanorod arrays were fabricated by annealing ZnO nanorod arrays grown on a substrate using a simple hydrothermal method. The annealing had a positive effect on the nanorod morphology, structure and optical properties. The porosity was closely related to the annealing temperature. After heating at 450 °C, pores appeared on the nanorods. It was demonstrated that the porosity could be exploited to improve the visible light absorption of ZnO and reduce the bandgap from 3.11 eV to 2.99 eV. A combination of improved charge separation and transport of the heat-treated ZnO thus led to an increase in the photoelectrochemical properties. At an irradiation intensity of 100 mW/cm−2, the photocurrent density of the porous nanorod array was approximately 1.3 mA cm−2 at 1.2 V versus Ag/AgCl, which was five times higher than that of the ZnO nanorods. These results revealed the synthesis of promising porous ZnO nanorods for photoelectrochemical applications.


CrystEngComm ◽  
2017 ◽  
Vol 19 (41) ◽  
pp. 6085-6088 ◽  
Author(s):  
Amany Ali ◽  
DongBo Wang ◽  
JinZhong Wang ◽  
ShuJie Jiao ◽  
FengYun Guo ◽  
...  

The ultraviolet luminescence of ZnO nanorods was greatly enhanced through introducing an AlN buffer layer.


Author(s):  
T. S. Rudnev ◽  

One of the primary goals of the European Union’s membership conditionality is to promote stability and de-mocracy outside its immediate borders. Thus, being subjected to EU conditionality can be a factor affecting democratization processes in candidate countries. The article attempts to locate the study of EU-induced de-mocratization within the bigger theoretical picture of democratization studies. This article starts with a dis-cussion of different theories and approaches to the study of democratization, including the theory of norm diffusion (Risse, 1999) and the theory of linkage/leverage (Levitsky and Way, 2002). After indicating how the study of EU-induced democratization can be and has been approached within those theories, and the arti-cle proceeds with an outline and analysis of a rather new approach utilizing an External Incentives Model (Schimmelfennig, 2003), which stemmed from the growing body of free-standing research dedicated specifi-cally to the problem of Europeanization. Thus, the article demonstrates that the study of Europeanization of candidate countries not only invited the application of pre-existing theoretical frameworks from different subdisciplines but also produced a new theoretical framework dedicated specifically to the study of Europe-anization.


2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Da Zhang ◽  
Yuanyi Wang ◽  
Liang Chen ◽  
Chengjing Xiao ◽  
Jing Feng ◽  
...  

A simple two-step method of growing ZnO nanorod arrays on the surface of BiOI nanosheets was developed under mild environment. The hierarchical structure of ZnO arrays@BiOI nanosheets was characterized by various measurements like X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray detector. The optical absorption of the ZnO arrays@BiOI nanosheets composite was investigated by UV-Vis diffuse reflectance spectra. The photocatalytic degradation of methanol orange under visible light shows that the obtained ZnO arrays@BiOI nanosheets heterostructures exhibit enhanced photocatalytic activity, contrasting to the sum of BiOI nanosheets and ZnO nanorods. The mechanism of the photocatalytic process was discussed. This method of growing ZnO nanorod arrays on other nanosheets also provides a potential method to fabricating other complex structures.


2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Weixuan Jing ◽  
Han Qi ◽  
Jiafan Shi ◽  
Zhuangde Jiang ◽  
Fan Zhou ◽  
...  

With ZnO nanorods hydrothermally synthesized on manually assembled arrays of optical fiber cores, 3D arrays of ZnO nanorod-based cylindrically hierarchical structures with nominal pitch 250 μm or 375 μm were constructed. Based on micrographs of scanning electron microscopy and image processing operators of MATLAB software, the 3D arrays of cylindrically hierarchical structures were quantitatively characterized. The values of the actual diameters, the actual pitches, and the parallelism errors suggest that the process capability of the manual assembling is sufficient and the quality of the 3D arrays of cylindrically hierarchical structures is acceptable. The values of the characteristic parameters such as roughness, skewness, kurtosis, correlation length, and power spectrum density show that the surface morphologies of the cylindrically hierarchical structures not only were affected significantly by Zn2+concentration of the growth solution but also were anisotropic due to different curvature radii of the optical fiber core at side and front view.


RSC Advances ◽  
2014 ◽  
Vol 4 (84) ◽  
pp. 44452-44456 ◽  
Author(s):  
Y. Yin ◽  
Y. Sun ◽  
M. Yu ◽  
X. Liu ◽  
B. Yang ◽  
...  

Annealing or plasma pre-treating the ZnO seed layer influences the nucleation and hydrothermal growth of ZnO nanorods and their photoluminescence.


2015 ◽  
Vol 3 (8) ◽  
pp. 4568-4577 ◽  
Author(s):  
A. Resmini ◽  
I. G. Tredici ◽  
C. Cantalini ◽  
L. Giancaterini ◽  
F. De Angelis ◽  
...  

Soft-lithography of Zn-loaded hydrogels and a subsequent hydrothermal growth process yield self-assembling networks of bridging ZnO nanorods (NRs). They are grown on seeding micropillars of ZnO until they touch, forming junctions that provide a preferred electrical path for the operative current of functional devices (e.g. gas senors).


Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1113 ◽  
Author(s):  
Bogumiła Kumanek ◽  
Tomasz Wasiak ◽  
Grzegorz Stando ◽  
Paweł Stando ◽  
Dariusz Łukowiec ◽  
...  

Despite the widespread use of sonication for individualization of nanomaterials, its destructive nature is rarely acknowledged. In this study, we demonstrated how exposure of the material to a hostile sound wave environment can be limited by the application of another preprocessing step. Single-walled carbon nanotubes (CNTs) were initially ground in a household coffee grinder, which enabled facile deagglomeration thereof. Such a simple approach enabled us to obtain high-quality CNT dispersion at reduced sonication time. Most importantly, electrical conductivity of free-standing films prepared from these dispersion was improved almost fourfold as compared with unground material eventually reaching 1067 ± 34 S/cm. This work presents a new approach as to how electrical properties of nanocarbon ensembles may be enhanced without the application of doping agents, the presence of which is often ephemeral.


Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 356
Author(s):  
Kasimayan Uma ◽  
Elavarasan Muniranthinam ◽  
Siewhui Chong ◽  
Thomas C.-K Yang ◽  
Ja-Hon Lin

This report presents the synthesis of ZnO nanorod/α-Fe2O3 composites by the hydrothermal method with different weight percentages of α-Fe2O3 nanoparticles. The as-synthesized nanorod composites were characterized by different techniques, such as X-ray diffraction (XRD), Fourier transform-infrared (FT-IR), field emission scanning electron microscopy (FE-SEM), electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS). From our results, it was found that the ZnO/α-Fe2O3 (3 wt%) nanorod composites exhibit a higher hydrogen evolution reaction (HER) activity when compared to other composites. The synergetic effect between ZnO and (3 wt%) of α-Fe2O3 nanocomposites resulted in a low onset potential of −125 mV, which can effectively produce more H2 than pure ZnO. The H2 production rate over the composite of ZnO/α-Fe2O3 (3 wt%) clearly shows a significant improvement in the photocatalytic activity in the heterojunction of the ZnO nanorods and α-Fe2O3 nanoparticles on nickel foam.


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