Synthesis and Characterization of Fluorine-Doped Tin Oxide Nanocrystals Prepared by Sol-Gel Method

2014 ◽  
Vol 977 ◽  
pp. 59-62 ◽  
Author(s):  
Jun Qing Tian ◽  
Hai Ying Shi ◽  
Wei Zheng

Fluorine-doped tin dioxide (FTO) nanocrystals were prepared with sol–gel method using SnCl4·5H2O and NH4F as precursor material. The FTO was characterized with X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Differential Thermal Analysis and Thermal Grativity (DTA-TG) and Infrared Radiation (IR) respectively. The electrical property was measured with Hall Effect Sensor. The result of XRD and SEM shows that FTO nanocrystal size is about 20 nm and the dimension of the grain is about 300 nm. IR spectrum analysis proves fluorine doping. The crystal phase transformation was discussed with DTA-TG curve. When the sintering temperature is 450°C, the sintering time is 60 min, and the molar ratio of F to Sn is 2:10, the sheet resistance of FTO film is 107Ω/□.

2004 ◽  
Vol 03 (06) ◽  
pp. 749-755 ◽  
Author(s):  
YING LI ◽  
SUO HON LIM ◽  
TIM WHITE

The properties influencing the photocatalytic activity of TiO 2 particles have been suggested to include the surface area, crystallinity, crystallite size and crystal structure. Therefore, manipulation of the microstructure of titania, especially of nanocrystalline powders, is very important in the preparative process. In this study, nanocrystalline TiO 2 powders with controlled particle size and phase composition were synthesized at low temperature (<80°C) by a modified sol–gel method. The effects of gelation temperature were systematically investigated. It was found that this parameter played a critical role in determining the crystallinity of single phase anatase. With increasing gelation temperature, the crystallinity of anatase improved initially and then decreased if the temperature was raised to 80°C. These nanomaterials were characterized comprehensively by powder X-ray diffraction (including Rietveld analysis), high-resolution transmission electron microscopy, DSC/TGA thermal analysis and UV–Vis spectrometry.


2002 ◽  
Vol 17 (3) ◽  
pp. 590-596 ◽  
Author(s):  
G. Ennas ◽  
M. F. Casula ◽  
G. Piccaluga ◽  
S. Solinas ◽  
M. P. Morales ◽  
...  

γ–Fe2O3/SiO2 and Fe/SiO2 nanocomposites, with a Fe/Si molar ratio of 0.25, were prepared by the sol-gel method starting from ethanolic solutions of tetraethoxysilane and iron (III) nitrate. After gelation the xerogels were oxidated or reduced. Samples were investigated by transmission electron microscopy, x-ray diffraction, differential scanning calorimetry, and thermogravimetry. Magnetic properties of the samples were investigated at room temperature (RT) and at 77 K. Nanometric particles supported in the silica matrix were obtained in all cases. Bigger particles (10 nm) were obtained in the case of Fe/SiO2 nanocomposites with respect to the γ–Fe2O3/SiO2 samples (5–8 nm). A slight effect of sol dilution on particle size was observed only in the case of γ–Fe2O3/SiO2 nanocomposites. A superparamagnetic behavior was shown at RT only by γ–Fe2O3/SiO2 nanocomposites. Iron-based composites exhibited coercivity values higher than 700 Oe at RT.


2011 ◽  
Vol 393-395 ◽  
pp. 1287-1290
Author(s):  
Min Wang ◽  
Qiong Liu ◽  
Qi Xing

The N-doped Cu11O2 (VO4)6 photocatalyst was prepared using the sol-gel method. Techniques of X-ray diffraction (XRD), scanning electron microscope (SEM) have been employed to characterize the as-synthesized materials. During liquid phase photocatalytic degradation of Methy lorange(MO) under the UV-light, the as-prepared N-doped Cu11O2 (VO4)6 exhibits higher activity than the pure Cu11O2 (VO4)6 without doped N. It found that the N-doped Cu11O2 (VO4)6 prepared with the molar ratio of citric acid to metal inons be 2:1, N/Cu molar ratio of 12%, pH=7 and calcinated under 500°C for 4 hours was pure triclinic phase. In this conditions, the sample had highest photocatalytic activity with the photodegradation rate was about 94.42% or so in 60min under 20W ultraviolet lamp.


2006 ◽  
Vol 972 ◽  
Author(s):  
C. Hu ◽  
W. Zhang ◽  
H. Hao ◽  
M. H. Cao ◽  
S. J. Lai ◽  
...  

AbstractIn the study Li4/3Ti5/3O4 thin films were deposited on Pt substrates by sol-gel method using a spin coator. The coated films are dried at 310-360 °C, and then annealed at 500-800 °C for 30min. The prepared films were characterized by X-ray diffraction, atomic force microscope and scanning electron microscope. The results indicated that the prepared film belonged to a spinel structure and had a uniform morphology. Electrochemical properties of the prepared electrode films were evaluated by using a discharge and charge test. From these results, it can be showed that the thin film electrode annealed at 700 °C exhibited good crystallinity, smooth surface morphology, high capacity, and good rechargeability. Therefore, This film was therefore suitable for use as an anode for thin-film microbatteries.


2013 ◽  
Vol 829 ◽  
pp. 544-548 ◽  
Author(s):  
Hossein Heydari ◽  
Rahim Naghizadeh ◽  
H.R. Samimbanihashemi ◽  
Maryam Hosseini-Zori

Hematite widely used since ancient times as a pigment but its chemical and thermal stability at high temperatures application is not enough. In this study, hematite nanoparticles were included into the zircon matrix and its stability was increased. Fe2O3 ZrSiO4 nanocomposite with Fe/Zr molar ratio of 5 to 30% was synthesized from Si and Zr alkoxides by sol-gel method. The products of the solgel method were calcined in the 1200°C /2.5 h. The structural and morphological characteristics of nanocomposite are determined by X-ray diffraction (XRD), simultaneous thermal analysis (STA) and scanning electron microscopy (SEM) investigations. The results indicate that formation of zircon promoted with iron addition. Finally, colorimetric parameters of the glazed ceramic samples were measured by the CIE colorimetric method. It was found that the samples withe 20% molar Fe has the highest red shade and is the best color according to the a* parameter.


2012 ◽  
Vol 545 ◽  
pp. 157-160 ◽  
Author(s):  
Nurhanna Badar ◽  
Nor Fadilah Chayed ◽  
Rusdi Roshidah ◽  
Norashikin Kamarudin ◽  
Norlida Kamarulzaman

In this work, the band gap energies of magnesium oxide (MgO) were investigated to see if calcination time affects the band gap energies of the MgO. MgO nanomaterials have been prepared by a sol-gel method. MgO precursors produced were calcined at a temperature of 600 °C for 24 hours and 48 hours. The structural characterization of samples is achieved using X-Ray Diffraction (XRD) and the morphology as well as particle size of MgO were examined by Field Emission Scanning Electron Microscopy (FESEM). UV-Vis NIR spectroscopy was used to determine the band gap energies of the materials. From the results, the band gap energy of the MgO with a longer heating time exhibited a higher value.


Author(s):  
Haiwen Chen ◽  
Shengli Hu ◽  
Ge Zhang ◽  
Zhengming Jiang ◽  
JiaJun Mo ◽  
...  

Multiferroic nanocrystalline Bi[Formula: see text]Sr[Formula: see text]FeO3 ([Formula: see text], 0.05, 0.1) samples were synthesized using the sol–gel method and characterized by powder X-ray diffraction, Mössbauer spectroscopy and SQUID system. The small-angle X-ray diffraction analysis showed that the sample underwent phase transition from rhombohedral to pseudo-cubic structure with the enhancement of Sr content. In addition, impurity peaks gradually diminished, indicating that content of impurities of samples reduced. Furthermore, it can be determined that there is only Fe[Formula: see text] in all the samples and impurity phase that existed in the samples was Bi[Formula: see text]FeO[Formula: see text] by fitting Mössbauer spectra. It is further confirmed that Bi[Formula: see text] Sr[Formula: see text]FeO3 samples were generated by oxygen vacancy equilibrium valence state when Sr[Formula: see text] ions replaced Bi[Formula: see text] ions. The change of quadrupole splitting indicated that a low concentration of Sr[Formula: see text] ions diffused homogeneously in the sample. Magnetization measurement showed that the magnetization of the sample increased gradually with the substitution of Bi[Formula: see text] by nonequivalent Sr[Formula: see text] ions, which can be ascribed to the decrease of grain size and the increase of oxygen vacancy and specific surface in the samples.


2016 ◽  
Vol 680 ◽  
pp. 189-192
Author(s):  
Zhao Jun Liu ◽  
Kang Ning Sun ◽  
Ai Min Li ◽  
Xiao Ning Sun ◽  
Shu Pin Zhang

In this study, LiZn ferrites with different content of CNTs (1%-9%) were successfully prepared by a sol-gel method. X-ray diffraction pattern exhibit a relatively high crystallinity of the Li0.25Zn0.5Fe2.25O4/CNTs composite, and the CNTs still exist after acid treatment and subsequent heat treatment. Then the composite was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), the results demonstrate that the particles are nearly spherical in shape and agglomerated to some extent. By a sol-gel method and subsequent calcination, the temperature of LiZn ferrites/CNTs temperature control biomaterials gradually increase and maintain at a certain temperature in the alternating magnetic field, so it can be a potential material used for hyperthermia applications.


2007 ◽  
Vol 353-358 ◽  
pp. 2111-2114 ◽  
Author(s):  
Chun Cheng Zhu ◽  
Yan Hong ◽  
Jian Guang Zhang ◽  
Bai Bin Zhou

Cr2O3 nano-powders were successfully fabricated with using chromium nitrate and aqueous ammonia as starting material and urea as dispersant agent by sol-gel method. The formation of crystalline phase during heat treatment of dry gel was characterized by differential thermogravimetry (DTG) and X-ray diffraction (XRD) techniques and the temperature of calcination was determined as 400°C. Scanning electron microscopy (SEM) was utilized to observe the morphology of the as-fabricated Cr2O3 particles. The results showed that Cr2O3 particles are spherical or square with little agglomeration and a diameter of about 30 nm. The specific surface area of Cr2O3 particles was measured as 44.23 m2/g by Brunauer-Emmett-Teller (BET).


2021 ◽  
Vol 37 (1) ◽  
pp. 177-180
Author(s):  
Alimuddin Alimuddin ◽  
Mohd Rafeeq

Synthesis of strontium oxide nanoparticles was carried out by sol –gel method using strontium nitrate and sodium hydroxide at room temperature which is very simple and cost effective. The characterization of strontium oxide nanoparticles was done using X-ray diffraction, scanning electron microscopy (SEM) and Fourier transform infra-red (FTIR). X-ray diffraction pattern indicates that the nanoparticles are crystalline in nature. The crystalline size of strontium oxide nanoparticle was calculated by Debye-Scherrer formula. The crystalline sizes are about 80nm. The morphology of nanoparticles was observed and investigated using SEM. The material at room temperature, calcined at 2000C, 400 0C and 6000C respectively shows pseudo spherical shape, cubic form and finally it becomes cylindrical this shows that there is a agglomeration with increase in temperature. FTIR spectrum of strontium oxide shows the peak at 854.64 cm-1 which is due to Sr -O bond.


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