Using a Sol-Gel Method to Prepare the TiO2/CNTs Nanocomposite

2014 ◽  
Vol 529 ◽  
pp. 108-111 ◽  
Author(s):  
Sheng Hao Meng ◽  
Yan Jun ◽  
Hong Guang Li ◽  
Shi Guo Du

Summarizd the methods of oxide coated on the surface of carbon nanotubes. Using carbon nanotubes (CNTs) as template, TiO2/CNTs nanocomposite was prepared by a sol-gel method. Urea as a promoter, obtained by the slow hydrolysis of tetrabutyl titanate Ti (OH)4 precursor is deposited on the carbon nanotubes, is further dehydrated to form TiO2. Its structure was characterized by X-ray energy spectroscopy (EDS) and scanning electron microscopy (SEM), and obtain uniform coating of TiO2/CNTs composites

2021 ◽  
Author(s):  
V Maphiri ◽  
L Melato ◽  
Mhlongo ◽  
TT Hlatshwayo ◽  
TE Motaung ◽  
...  

Abstract Un-doped and ZnAlxO(1.5x + 1):0.1% Tb3+ (ZAOT) nano-powders were synthesized via citrate sol-gel method. The Alx moles were varied in the range of 0.25 ≤ x ≤ 5.0. The X-ray powder diffraction (XRD) data revealed that for the x < 1.5, the prepared samples crystal structure consists of mixed phases of the cubic ZnAl2O4 and hexagonal ZnO phases, while for the x ≥ 1.5 the structure consists of single phase of cubic ZnAl2O4. This was confirmed by the Raman and Fourier-Transform Infrared (FTIR) vibrational spectroscopy. Scanning electron microscopy (SEM) showed that varying Alx moles influences the morphology while Transmission electron microscopy (TEM) shows the dual morphology at x < 1.5. The photoluminescence (PL) revealed intense and distinct emissions attributed to both the host and Tb3+ transitions. The emission intensity highly depends on the Alx moles. The International Commission on Illumination (CIE) colour chromaticity showed that the emission colour could be tuned by varying the Alx moles.


2012 ◽  
Vol 1494 ◽  
pp. 253-258
Author(s):  
Dan Jiang ◽  
Songwei Han ◽  
Xuelian Zhao ◽  
Jinrong Cheng

ABSTRACTBa0.6Sr0.4TiO3 (BST) thin films were deposited on La0.5Sr0.5CoO3 (LSCO) buffered Ti substrates. Both BST and LSCO were prepared by sol-gel method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were used to investigate the effect of LSCO sol concentration on the crystallinity and surface morphology of the films. The results show that with the increase of LSCO sol concentration, BST films show variation of the structure and dielectric properties. BST films for LSCO of 0.2 mol/L exhibit a better crystallinity and improved dielectric properties, with the tunability, dielectric constant and tanδ of 30%, 420 and 0.028 respectively.


1996 ◽  
Vol 5 (1) ◽  
pp. 096369359600500 ◽  
Author(s):  
R. Rodríguez ◽  
J. Coreño ◽  
J.A. Arenas ◽  
V.M. Castaño

The growth of hydroxyapatite, a calcium phosphate, on silica particles prepared by the sol-gel method is reported. The size of the silica sols was controlled by changing the pH of water before the mixing with the alcoxide. Particle size profiles of sols were obtained by using dynamical light scattering. The characterisation of the composites, of nanometer sizes, was performed by employing X-ray diffraction, scanning electron microscopy and Raman spectroscopy.


2020 ◽  
Vol 840 ◽  
pp. 454-458
Author(s):  
Adya Rizky Pradipta ◽  
Kurniawan Mauludi ◽  
Indriana Kartini ◽  
Eko Sri Kunarti

TiO2 modified Fe3O4 nanocomposite as photocatalyst in CO2 indirect reduction was synthesized by an ultrasonic-assisted sol-gel method and its photocatalytic activity was studied as well. The modification of the TiO2 composite was attempted to modify titanium dioxide to have better performance as a photocatalyst. Magnetite synthesis was carried out by the sono-coprecipitation method with the addition of the capping agent. The magnetite was coated with TiO2 via the sol-gel method under ultrasonic irradiation. The products were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectrophotometry (FT-IR), transmission electron microscopy (TEM), and turbidimetry. The final product was also analyzed by diffuse reflectance UV-Visible (DR-UV) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX). The product of indirect reduction was analyzed by gas chromatography-mass spectrometry (GC-MS). Photocatalytic reaction with Fe3O4/TiO2 nanocomposite produced a higher concentration of methanol than using TiO2. Methanol concentration produced from the photocatalytic reaction using TiO2 and Fe3O4/TiO2 was 6.63% and 16.82%.


2013 ◽  
Vol 740 ◽  
pp. 473-477
Author(s):  
Yi Zhang ◽  
Cai Li Zhang ◽  
Xiang Meng ◽  
Guo Qin Cao ◽  
Chuan Shuai Li

TiO2 films were prepared on the AZ31 Mg alloy substrate by sol-gel method. The morphology was characterized via X-ray diffractometer (XRD), scanning electron microscopy (SEM) and energy disperses spectroscopy (EDS). The corrosion rate of the coated AZ31 mg alloy was tested with the method of orthogonal experiment design. The influence of the hydrolysis temperature, coating times, calcinations temperature and time was investigated.


2011 ◽  
Vol 320 ◽  
pp. 135-139
Author(s):  
Yung Kuan Tseng ◽  
Ming Hung Chuang ◽  
Yen Cheng Chen

This study proposes a novel sol-gel method of fabricating the two-dimensional flakes polycrystalline zinc oxide (ZnO). Apply zinc acetate dehydrate in glycerol and hydrolyzed to get the precursor zinc alkoxide particles at 160°C, and self-assemble into flakes ZnO nanostructures, and then got higer crystallinity polycrystalline ZnO after calcination for one hour at 500°C. Field-emission scanning electron microscopy (FE-SEM) was used to observe the morphology of the flakes. Its size got to a few μm2. Analyze the crystal structure and crystallinity by X-ray powder diffraction (XRD). After calcination for one hour at 500°C, we can determine it is the hexagonal wurtzite structure of ZnO. And TGA/DSC to observe the loss and phase change of the solution. The Study has successfully synthesized ZnO polycrystalline flakes by sol-gel method.


2014 ◽  
Vol 881-883 ◽  
pp. 960-963 ◽  
Author(s):  
Ji Qi ◽  
Bin Zhao ◽  
Naisen Yu ◽  
Chen Niu ◽  
Guan Gran Sun

A new process was developed for synthesizing tungsten-doped vanadium dioxide VO2(M) from ammonium metavanadate. The process includes obtaining V2O5by pyrolysing NH4VO3, doping tungsten in V2O5by sol-gel method, and reducing V2O5to VO2(M) with hydrazine by hydrothermal method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were applied to characterizing the product. The experimental results indicated that tungsten doped VO2(M) nanoparticles were successfully synthesized. The product VO2(M) presents mainly rod-like and block-like morphology. The phase transition temperature decreases with tungsten doped amount increasing, the phase transition takes place over the range from 36.23°C to 62.16°C and the largest enthalpy of the phase transition is 16.24J/g.


2019 ◽  
Vol 64 (1) ◽  
pp. 61-74 ◽  
Author(s):  
Behnam Khanizadeh ◽  
Morteza Khosravi ◽  
Mohammad A. Behnajady ◽  
Ali Shamel ◽  
Behrouz Vahid

In this study, La and Mg doped, and co-doped ZnO nanoparticles were prepared using the sol-gel method. The prepared samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DRS), and N2 physisorption techniques. The XRD results indicated that the prepared nanoparticles can be well adopted by the hexagonal wurtzite structure crystal and there are no second impurity peaks. Studies of the FESEM, EDX and TEM have shown that the samples have uniform spherical-like morphology with a homogenous distribution. The incorporation of La and Mg into the ZnO lattice had no effect on the morphology of the nanoparticles, but a reduction in the size of the grains (≈ 14 nm to ≈ 7 nm) was observed due to the insertion of these ions. The results of N2 physisorption indicated that there was an increase in BET surface area and pore volume for doped and co-doped samples. The results of DRS showed an increase in band gap energy and a blue shift at the absorption edge for doped and co-doped samples. The photocatalytic activity of the prepared catalysts was evaluated in the removal of RhB under UVA irradiation. The results showed that Mg5%-La5%/ZnO had the highest photoactivity (91.18 %) among all samples.


2016 ◽  
Vol 254 ◽  
pp. 200-206 ◽  
Author(s):  
Catalina Nuțescu Duduman ◽  
María Isabel Barrena Pérez ◽  
José Maria Gómez de Salazar ◽  
Ioan Carcea ◽  
Daniela Lucia Chicet ◽  
...  

Nanostructured SnO2 was prepared based on the sol-gel method used in the preparation of crystalline metal oxides. Sol-gel process can be described as a forming network of oxide polycondensation reaction of a molecular precursor in a liquid. Six experiments were carried out. Morphological structures and chemical composition were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) after calcination. It is noted that TEM images show that the spheres consist from nanocrystals, quantitative EDS analysis of the chemical composition shows an absence of the chlorine, which is a desired fact. For structural characterization of the material we used X-Ray Diffraction (XRD). The X-ray diffraction pattern for all samples indicates peaks which are agreeable with standard diffraction pattern of SnO2. The particle size of all samples was in the range of 28-92 nm calculated according to Scherrer equation.


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