Template-Free Sonochemical Preparation of ZnO Cauliflower-Like Microstructures

2010 ◽  
Vol 663-665 ◽  
pp. 125-128
Author(s):  
Chong Hai Deng ◽  
Han Mei Hu ◽  
Shang Lin Wang ◽  
Guo Quan Shao

Cauliflower-like ZnO superstructures composed of nanoparticles in large scale were successfully synthesized only using Zn(CH3COO)2•2H2O and triethanolamine (TEA) aqueous solution mixtures via a template-free sonochemical process at the ambient condition. A number of techniques, including X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), UV-visible absorption and photoluminescence (PL) were used to characterize the obtained ZnO products. It has been interestingly found that UV-Vis absorption spectrum shows not only a weak and sharp peak at 367 nm in ultraviolet region but also a strong and broad band centered at 564 nm in visible region. The possible formation mechanism of ZnO cauliflower-like structure is also proposed.

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Honghui Teng ◽  
Shukun Xu ◽  
Dandan Sun ◽  
Ying Zhang

Fe-doped TiO2nanotubes (Fe-TNTs) have been prepared by ultrasonic-assisted hydrothermal method. The structure and composition of the as-prepared TiO2nanotubes were characterized by transmission electron microscopy, X-ray diffraction, and UV-Visible absorption spectroscopy. Their photocatalytic activities were evaluated by the degradation of MO under visible light. The UV-visible absorption spectra of the Fe-TNT showed a red shift and an enhancement of the absorption in the visible region compared to the pure TNT. The Fe-TNTs were provided with good photocatalytic activities and photostability and under visible light irradiation, and the optimum molar ratio of Ti : Fe was found to be 100 : 1 in our experiments.


2012 ◽  
Vol 502 ◽  
pp. 164-168
Author(s):  
Ling Xu ◽  
Han Mei Hu ◽  
Hai Yan Xu

Novel mace-like (wolf-teeth clubs) CdS nanostructures were successfully prepared on a large scale using CdCl2•2.5H2O and NH2CSNH2 as starting materials through a convenient mixed-solvothermal route. The as-synthesized products were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDX), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and UV-visible absorption spectroscopy. The experimental results reveal that the morphology of CdS products was greatly affected by the volume ratio of anhydrous ethanol and distilled water. The possible mechanism for the formation of mace-like CdS nanostructures is simply discussed.


2019 ◽  
Vol 34 (3) ◽  
pp. 242-250 ◽  
Author(s):  
J. Anike ◽  
R. Derbeshi ◽  
W. Wong-Ng ◽  
W. Liu ◽  
D. Windover ◽  
...  

Structural characterization and X-ray reference powder pattern determination have been conducted for the Co- and Zn-containing tridymite derivatives Ba(Co1−xZnx)SiO4 (x = 0.2, 0.4, 0.6, 0.8). The bright blue series of Ba(Co1−xZnx)SiO4 crystallized in the hexagonal P63 space group (No. 173), with Z = 6. While the lattice parameter “a” decreases from 9.126 (2) Å to 9.10374(6) Å from x = 0.2 to 0.8, the lattice parameter “c” increases from 8.69477(12) Å to 8.72200(10) Å, respectively. Apparently, despite the similarity of ionic sizes of Zn2+ and Co2+, these opposing trends are due to the framework tetrahedral tilting of (ZnCo)O4. The lattice volume, V, remains comparable between 626.27 Å3 and 626.017 (7) Å3 from x = 0 to x = 0.8. UV-visible absorption spectrum measurements indicate the band gap of these two materials to be ≈3.3 and ≈3.5 eV, respectively, therefore potential UV photocatalytic materials. Reference powder X-ray diffraction patterns of these compounds have been submitted to be included in the Powder Diffraction File (PDF).


2012 ◽  
Vol 621 ◽  
pp. 172-177 ◽  
Author(s):  
Su Hua Chen ◽  
Bi Xuan Wang ◽  
Xian Hua Qiu ◽  
Zhen Sheng Xiong

In order to improve ZnWO4 photocatalytic activity under visible light, the C, N-codoped ZnWO4 nanoparticles have been successfully synthesized by choosing C3N4 generated from tripolycyanamide pyrolysis as the source of Carbon and Nitrogen and the influence of C3N4 concentration on structural, optical and morphological properties of C, N-codoped ZnWO4 using X-ray diffraction (XRD), UV-visible spectroscopy, scanning electron microscopy (SEM) and photocatalytic decoloration of rhodamine B (RhB) aqueous solution under visible light. It was found that the presence of carbon and nitrogen could not improve the crystallization of ZnWO4 species but could enhance their photoabsorption property in the visible region. The results also showed that the photocatalytic activity of the as-prepared ZnWO4 is higher than that of pure ZnWO4 with the optimum effect occurring at RC3N4 = 9 % (the weight ratio of tripolycyanamide to ZnWO4)


2021 ◽  
Author(s):  
Nejeh Hannachi ◽  
Thierry ROISNEL ◽  
Faouzi HLEL

Abstract A new non-centrosymmetricorganotin (IV) hybrid compoundC5H14N2 [SnCl6] 2H2O was determined by single crystal X-ray diffraction at 150(2) K. Its crystal structure was solved by single crystal X-ray diffraction reveling that compound crystallizes in the orthorhombic system with Pbca space group with the following lattice parameters: a = 12.1486 (15) Å, b= 15.4571 (17) Å, c = 16.7610 (18) Å with Z = 8. The bonding between inorganic and organic entities in the compounds is realized by hydrogen bonding O−H…O ,O−H…Cl , NH • • • Cl, N-H…Cl and O−H…Cl. Finally,UV-visible absorption measurements exhibit two absorption bands (226 nm and 262 nm).The optical band gap (Eg) is deduced to be 3.46 Ev.


2019 ◽  
Vol 14 (11) ◽  
pp. 1523-1531
Author(s):  
Manjit Kaur ◽  
Rakesh Dogra ◽  
Narinder Arora ◽  
Navjeet Sharma ◽  
Rajesh Kumar

AC transport properties and dielectric response of sandwich geometry (Ag/CuPc/Ag) of CuPc(CuPc) thin films deposited using thermal evaporation technique have been studied within frequency range 1 Hz–10 KHz and in temperature range 303–383 K. Scanning electron microscope (SEM) investigations of these films reveal fiber like morphology. Crystalline natures of CuPc films have been characterized using X-ray diffraction for different temperatures. The molecular orientations in films for different substrate temperatures have been confirmed by Raman spectroscopy. The optical band gaps calculated from the UV–Visible absorption spectra is found to lie in the range 3.01–3.15 eV. Electrical conductivity of CuPc films increases with increase of temperature. The hole mobility values of CuPc films at different temperatures have been calculated using negative differential susceptance (–ΔB) technique. Both capacitance and dielectric constant have been found to decrease with the increase of frequency and temperature.


2007 ◽  
Vol 119 ◽  
pp. 239-242 ◽  
Author(s):  
Xiao Li Zhang ◽  
Young Hwan Kim ◽  
Young Soo Kang

Core/shell structured TiO2/ZnO was synthesized in a basic aqueous solution through a simple hydrolyzing method. The powder X-ray diffraction (XRD) and transmission electron microscopy of the initial TiO2/ZnO powder showed diffraction peaks corresponding to the ZnO and TiO2 phase. The structure and thickness of ZnO shell (about 2.5 nm) coated TiO2 surface as thin layers or nanoclusters, depends upon the reactant concentration and the reaction time. The characteristics of the optical absorption were described by UV-visible absorption spectroscopy.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 763
Author(s):  
Pejman Hajipour ◽  
Abbas Bahrami ◽  
Maryam Yazdan Mehr ◽  
Willem Dirk van Driel ◽  
Kouchi Zhang

This paper investigates the photocatalytic characteristics of Ag nanowire (AgNW)/TiO2 and AgNW/TiO2/graphene oxide (GO) nanocomposites. Samples were synthesized by the direct coating of TiO2 particles on the surface of silver nanowires. As-prepared AgNW/TiO2 and AgNW/TiO2/GO nanocomposites were characterized by electron microscopy, X-ray diffraction, UV/visible absorption spectroscopy, and infrared spectroscopy. Transmission electron microscope (TEM) images confirmed the successful deposition of TiO2 nanoparticles on the surface of AgNWs. The photocatalytic activity of synthesized nanocomposites was evaluated using Rhodamine B (RhB) in an aqueous solution as the model organic dye. Results showed that synthesized AgNW/TiO2/GO nanocomposite has superior photocatalytic activities when it comes to the decomposition of RhB.


Author(s):  
M. Abd Elkodous ◽  
(Dr.) Ahmed Hassaan ◽  
Prof (Dr.) KAUSHIK PAL ◽  
(Dr.) A I Ghoneim ◽  
(Dr.) Zizi Abdeen

Synthesis of macro-mesoporous Titania (Titanium dioxide-TiO2) nanospheres was successfully achieved using a modified template-free methodology to incorporate macroporous channels into a mesoporous TiO2 framework to form mixed macro-mesoporous TiO2 spheres (MMPT), which were doped with carbon dots (C-dots) to form improved nanocomposites (C-dots@MMPT). Elemental composition, surface bonding and optical properties of these nanocomposites were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR) and ultraviolet-visible absorption spectroscopy (UV-VIS). Evaluation of photocatalytic activity for each (C-Dots@MMPT) sample was performed via degrading the Methylene Blue (MB) dye compared with bare samples (MMPT) under visible light irradiation using 300 Watt halogen lamp.


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