scholarly journals Synthesis and Characterization of Nano-Tungsten Oxide Precipitated onto Natural Inorganic Clay for Humidity-Sensing Applications

Ceramics ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 120-127 ◽  
Author(s):  
Ahmed Afify ◽  
Ahmed Elsayed ◽  
Mohamed Hassan ◽  
Mohamed Ataalla ◽  
Amr Mohamed ◽  
...  

A wet chemical method was used to obtain tungsten oxide nanoparticles from tungsten tetrachloride and natural microfibrous inorganic clay (sepiolite) as a starting material. Precipitation of tungsten oxide species onto sepiolite under basic conditions and subsequent thermal treatment was investigated, prompted by the abundance of sepiolite in nature and the useful environmental applications that could be attained. Laser granulometry, X-ray diffraction, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), and high-resolution transmission electron microscopy (HR-TEM) techniques were used to study the particle-size distribution, the morphology, and the composition of the prepared sample. Our findings show the presence of tungsten oxide nanoparticles, which are less than 50 nm, on the needles of the modified sepiolite.

2012 ◽  
Vol 268-270 ◽  
pp. 176-179 ◽  
Author(s):  
Yang Rong Yao ◽  
Rong Ma ◽  
Xu Chun Song

In the present paper, the tungsten oxide nanoparticles were fabricated via a hydrothermal treatment of the H2WO4 precursors. The H2WO4 precursors were prepared by method of precipitation reaction between aqueous Na2WO4 and HCl solution. The products are characterized in detail by multiform techniques: scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray analysis. The results show that products are WO3 nanoparticles with diameter of about 100-150 nm.


Biomolecules ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 38 ◽  
Author(s):  
Banzeer Ahsan Abbasi ◽  
Javed Iqbal ◽  
Riaz Ahmad ◽  
Layiq Zia ◽  
Sobia Kanwal ◽  
...  

This study attempts to obtain and test the bioactivities of leaf extracts from a medicinal plant, Geranium wallichianum (GW), when conjugated with zinc oxide nanoparticles (ZnONPs). The integrity of leaf extract-conjugated ZnONPs (GW-ZnONPs) was confirmed using various techniques, including Ultraviolet–visible spectroscopy, X-Ray Diffraction, Fourier Transform Infrared Spectroscopy, energy-dispersive spectra (EDS), scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The size of ZnONPs was approximately 18 nm, which was determined by TEM analysis. Additionally, the energy-dispersive spectra (EDS) revealed that NPs have zinc in its pure form. Bioactivities of GW-ZnONPs including antimicrobial potentials, cytotoxicity, antioxidative capacities, inhibition potentials against α-amylase, and protein kinases, as well as biocompatibility were intensively tested and confirmed. Altogether, the results revealed that GW-ZnONPs are non-toxic, biocompatible, and have considerable potential in biological applications.


2008 ◽  
Vol 8 (3) ◽  
pp. 1398-1403 ◽  
Author(s):  
Liqin Liu ◽  
En Ma ◽  
Renfu Li ◽  
Xueyuan Chen

Eu3+:Gd2O3 nanorods were prepared by a hydrothermal method. X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and Fourier transform-infrared spectroscopy were used to characterize the resulting samples. Emission and excitation spectra were studied using xenon excited spectroscopic experiments at 10 K. Energy transfer from Gd3+ to Eu3+, from the band gap of the host to Eu3+, and from Eu3+ (S6) to Eu3+ (C2) was observed. The energy levels of Eu3+ at the C2 site of cubic Gd2O3 were experimentally determined according to the fluorescence spectra at 10 K, and fit well with the theoretical values. The standard deviation for the optimal fit was 12.9 cm−1. The fluorescent lifetime of 5D0 (2.3 ms at 295 K) was unusually longer than that of the bulk counterparts (0.94 ms), indicating a small filling factor (0.55) for the nanorod volume. However the lifetime of 5D1 was much shorter than that of the bulk counterparts, 65 μs at 10 K, 37 μs at 295 K.


2018 ◽  
Vol 43 (3-4) ◽  
pp. 201-210
Author(s):  
Raheleh Nikonam Mofrad ◽  
Sayed Khatiboleslam Sadrnezhaad ◽  
Jalil Vahdati Khaki

We determined the mechanism of mechanochemical synthesis of fluorapatite from CaO, CaF2 and P2O5 by characterisation of the intermediate compounds. We used atomic absorption spectroscopy, X-ray diffraction, field emission scanning electron microscopy, FTIR spectroscopy and transmission electron microscopy to find the transitional compounds. Investigation of the binary and ternary powder mixtures revealed the appearance of H3PO4, Ca(OH)2, Ca2P2O7 and CaCO3 as the intermediate compounds. At early stages of the milling, conversions of P2O5 to H3PO4 and CaO to Ca(OH)2 occurred in the wet atmosphere. Later, a combination of Ca(OH)2 and H3PO4 formed C a2P2O7 while the unreacted CaO was converted to CaCO3 by CO2 of the ambient atmosphere. Spherical crystalline Ca10 (PO4)6F2 particles formed after 48 hours of milling due to the reaction between Ca2P2O7, CaCO3 and CaF2.


2009 ◽  
Vol 08 (03) ◽  
pp. 277-279 ◽  
Author(s):  
MOHSEN OFTADEH ◽  
MASOUD SALAVATI-NIASARI ◽  
FATEMEH DAVAR

Zinc oxide nanoparticles were successfully prepared through the decomposition of zinc acetylacetonate precursor in oleylamine in the presence of triphenylphosphine. The products were characterized by X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy.


2004 ◽  
Vol 19 (5) ◽  
pp. 1369-1373 ◽  
Author(s):  
Guozhen Shen ◽  
Di Chen ◽  
Kaibin Tang ◽  
Yitai Qian

In this paper, we reported the rapid synthesis of disklike (ZnSe)2·EN precursor via a simple and convenient polyol method. Annealing the precursor in argon stream at 500 °C resulted in the formation of ZnSe crystals with unique quasi-network structure. The obtained samples were characterized by powder x-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, infrared absorbance spectra, and thermogravimetric analysis. The influence of PEG200 on the final products in the system was also discussed.


2013 ◽  
Vol 663 ◽  
pp. 421-425
Author(s):  
Zao Yang ◽  
Quan Hui Liu

Metallic oxide ZnO short-nanorod of 33-83 nm in diameters and length up to 0.3um.with biological compatibility are environmentally fabricated by organic solvent-assisted annealing pro- cess. The sample was characterized by X-ray diffraction, field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM). It demonstrates that the obtained ZnO short-nanorods have good crystal quality. A growth mechanism is proposed. This paper establish base for application of Metallic oxide short-nanorod to the area of bioscience in our future work.


2007 ◽  
Vol 22 (9) ◽  
pp. 2505-2511 ◽  
Author(s):  
M. Damayanti ◽  
T. Sritharan ◽  
S.G. Mhaisalkar ◽  
E. Phoon ◽  
L. Chan

The reaction mechanisms and related microstructures in the Cu/Si, Ru/Si, and Cu/Ru/Si metallization system were studied experimentally. With the help of sheet resistance measurements, x-ray diffraction, field-emission scanning electron microscopy, secondary ion mass spectroscopy, and transmission electron microscopy, the metallization structure with Ru barrier layer was observed to fail completely at temperatures around 700 °C, regardless of the Ru thickness because of the formation of polycrystalline Ru2Si3 followed by Cu3Si protrusions.


2019 ◽  
Vol 8 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Henam Sylvia Devi ◽  
Muzaffar Ahmad Boda ◽  
Mohammad Ashraf Shah ◽  
Shazia Parveen ◽  
Abdul Hamid Wani

Abstract In this report, aqueous phase green synthesis of iron oxide nanoparticle utilizing Platanus orientalis is elucidated for the first time. The phytoconstituents of the P. orientalis leaf extract serve a dual role as reducing and capping agent during the fabrication of iron oxide nanoparticles. The role of the leaf extract in the synthesis of iron oxide has been briefly demonstrated in this work. The tailored iron oxide particles were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray analysis, infrared spectroscopy, ultraviolet-visible spectroscopy, and dynamic light scattering technique. Nonetheless, X-ray diffraction pattern reveals the mixed phase nature of the ensuing iron oxide, i.e. α-Fe2O3 and γ-Fe2O3. The spherical oxide particles have an average diameter of 38 nm as determined from transmission electron microscopy. Infrared spectroscopy results confirmed the stabilization of iron oxide nanoparticles by the phytochemicals present in the leaf extract. Iron oxide nanoparticles show significant antifungal activity against Aspergillus niger and Mucor piriformis, employed as model fungi, but found to be more active toward M. piriformis.


2016 ◽  
Vol 7 ◽  
pp. 1129-1140 ◽  
Author(s):  
Wanggang Zhang ◽  
Yiming Liu ◽  
Diaoyu Zhou ◽  
Hui Wang ◽  
Wei Liang ◽  
...  

Using magnetron sputtering and heat treatment, Ag@TiO2 nanotubes are prepared. The effects of heat-treatment temperature and heating time on the evolution of Ag nanofilms on the surface of TiO2 nanotubes and microstructure of Ag nanofilms are investigated by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Ag atoms migrate mainly on the outmost surface of the TiO2 nanotubes, and fast diffusion of Ag atoms is observed. The diffusivity for the diffusion of Ag atoms on the outmost surface of the TiO2 nanotubes at 400 °C is 6.87 × 10−18 m2/s, which is three orders of magnitude larger than the diffusivities for the diffusion of Ag through amorphous TiO2 films. The activation energy for the diffusion of Ag atoms on the outmost surface of the TiO2 nanotubes in the temperature range of 300 to 500 °C is 157 kJ/mol, which is less than that for the lattice diffusion of Ag and larger than that for the grain boundary diffusion. The diffusion of Ag atoms leads to the formation of Ag nanocrystals on the outmost surface of TiO2 nanotubes. Probably there are hardly any Ag nanocrystals formed inside the TiO2 nanotubes through the migration of Ag.


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