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1.
Preparation and characterization of TiO<Subscript>2</Subscript> sol–gel modified nanocomposite films
In this study, the role of TiO2 MT-150A loading in the polymeric sol was investigated for the synthesis of immobilized TiO2 nanocomposite films on glass substrate using the MT-150A nanoparticles-modified sol–gel method. The nanocomposite film properties
were examined using different material characterization techniques including X-ray diffraction, X-ray photoelectron spectroscopy,
field emission scanning electron microscopy, UV–Vis spectrophotometer, Scotch tape test and pencil hardness test. The hydrophilicity
of films during UV/Vis irradiation and storage in a dark place were evaluated by a contact angle analyzer. The MT-150A loading
had a significant effect on the amount of crystallite phases in the films. However, increasing the MT-150A loading in the
sol resulted in an increase in rutile phase content. In addition, increasing MT-150A loading in the sol yielded films with
higher hydrophilicity but a concentration of 10–30 g/L MT-150A in the sol was found as the maximum for obtaining films with
good adherence on the glass substrate. 相似文献
2.
Akash Katoch Hohyeong Kim Taejin Hwang Sang Sub Kim 《Journal of Sol-Gel Science and Technology》2012,61(1):77-82
Highly stable TiO2 sols were prepared by adjusting the water-to-titanium molar ratio to ~4 in the process of hydrolysis and condensation of
titanium isopropoxide in ethanol with HNO3. Particularly, long-term stable TiO2 sols were prepared without adding any chemical additives. Anatase TiO2 nanocrystallites with sizes of 3–5 nm in diameter were uniformly dispersed in the stable sol. Crystallized TiO2 films were successfully deposited on Si (100) using the stable sol via a dip-coating process with low temperature curing
at as low as 100 °C. The synthesized TiO2 sols and films are promising for use in flexible or dye-sensitized solar cells. 相似文献
3.
This study describes the In2S3 semiconductor thin film coating on glass substrate by sol–gel method. The In2S3 thin film samples were prepared and examined by the X-ray diffraction (XRD), the UV–visible optical absorption and transmission
study, and the Scanning Electron Microscope (SEM) image analyses. The XRD analysis results show that the In2S3 semiconductor thin films prepared by sol–gel method is formed at T~360–520 °C temperature interval. Band gap energy and optical
absorption spectrum analysis of the In2S3 thin films reveal that Eg~2.51 eV for the In2S3 thin films. According to the EDX result the film was In-rich with the In/S = 1.42 ratio. The thickness of prepared In2S3 layer is about 400 nm. 相似文献
4.
Chao-Ching Chang Liao-Ping Cheng Feng-Hsi Huang Chia-Ying Lin Chi-Fa Hsieh Wei-Hong Wang 《Journal of Sol-Gel Science and Technology》2010,55(2):199-206
In this study, UV-curable hybrid thin films were successfully prepared from TiO2 and TiO2 hybrid sols containing the acrylic monomer DPHA on PMMA substrates. The prepared TiO2 and TiO2 hybrid sols showed long-term storage stability and can provide operating control for the preparation of high-refractive-index
hybrid thin films. The existence of interaction between the TiO2 particle and the coupling agent was evidenced by FT-IR and UV–visible spectra. All hybrid thin films showed good adhesion
to the PMMA substrate with refractive index falling over the range 1.64–1.77. These results suggested the potential application
of present TiO2 hybrid films in optical devices, such as anti-reflective coatings. 相似文献
5.
Nursen Avci Philippe F. Smet Hilde Poelman Nigel Van de Velde Klaartje De Buysser Isabel Van Driessche Dirk Poelman 《Journal of Sol-Gel Science and Technology》2009,52(3):424-431
Stable TiO2 sols were prepared using two non-aqueous sol–gel processes with titanium n-butoxide and titanium isopropoxide, respectively. Crystallization and phase transitions of powders and thin films were studied
by ex situ and in situ X-ray diffraction. For both methods, TiO2 began to crystallize around 320 °C in air. Using helium instead of air during heat treatment slowed down the crystallization
and substoichiometric powders were formed. TiO2 thin films were obtained by spin coating. The morphology of the films was evaluated using scanning electron microscopy. The
films were homogeneous and transparent in the visible range. The effect of the heating atmosphere and the type of substrate
was investigated. 相似文献
6.
Yang Ren Gaoyang Zhao Chenxi Zhang Yuanqing Chen 《Journal of Sol-Gel Science and Technology》2012,61(3):565-569
CuAlO2 thin films were deposited on quartz substrates by sol–gel process using copper acetate monohydrate and aluminum nitrate nanohydrate
as starting materials and isopropyl alcohol as solvent. The influence of annealing temperature on the film structure and the
phase evolution of CuAlO2 films were investigated, so as to obtain CuAlO2 films with superior performance. The phase compositions of the films were dependent on the annealing temperature. The films
annealed at temperatures below 400 °C were amorphous while those annealed above 400 °C were polycrystalline. The phases of
CuO and CuAl2O4 appeared gradually with the increase of annealing temperature. When the heat treatment temperature was elevated to 900 °C,
the uniform and dense films with single phase of CuAlO2 were obtained, with a resistivity of 15 Ωcm. The transmittance of the 310 nm-thick CuAlO2 film is 79% at 780 nm and the direct optical band gap is 3.43 eV. 相似文献
7.
8.
TiO2 films were deposited on soda-lime and borosilicate glass substrates, their optical and microstructural properties were investigated.
X-ray diffraction showed significant differences between the sample series. Films deposited on the upper surface of soda-lime
glass substrates showed higher indices of refraction than those prepared on the lower surface that had been in contact with
the tin bath during float glass production. Results indicate that these differences not only result from different optical
properties of the TiO2 backbone material due to alkali contamination but that also different film porosities can measured by ellipsometric porosimetry. 相似文献
9.
Davinder Singh Nafa Singh Sunil Dutta Sharma Chander Kant C. P. Sharma R. R. Pandey K. K. Saini 《Journal of Sol-Gel Science and Technology》2011,58(1):269-276
Nickle and iron doped TiO2 thin films were prepared on glass substrates by sol–gel dip coating process. Indirect and direct optical energy gaps were
calculated with the incorporation of different concentrations of both the ions. Indirect bandgap was found to be a strong
function of the dopant concentration, whereas direct energy gap has negligible dependence on the nature of dopant and its
concentration. Direct energy gap has always been found to retain a value higher than the indirect energy gap. Variation of
observed energy gap properties shows a trend similar to that reported on the basis of numerical calculations or the samples
obtained by other techniques. Increase in refractive index and corresponding density of the film sample does not support the
change in turn over frequency. The influence of crystalline phase change is also ruled out by XRD investigations. It is concluded
that red shift of band edge absorption takes place by incorporation of dopant and sol–gel dip coating technique offers an
effective low cost route to the production of these coatings. 相似文献
10.
Masoud Salavati-Niasari Fatemeh Davar Masoud Farhadi 《Journal of Sol-Gel Science and Technology》2009,51(1):48-52
Nanocrystalline Copper aluminate (CuAl2O4) was prepared by sol–gel technique using aluminum nitrate, copper nitrate, diethylene glycol monoethyl ether and citric acid
were used as precursor materials. This method starts from of the precursor complex, and involves formation of homogeneous
solid intermediates, reducing atomic diffusion processes during thermal treatment. The formation of pure crystallized CuAl2O4 nanocrystals occurred when the precursor was heat-treated at 600 °C in air for 2 h. The stages of the formation of CuAl2O4, as well as the characterization of the resulting compounds were done using thermo–gravimetric analysis, X-ray diffraction,
scanning electron microscopy and Fourier transform infrared spectroscopy. The products were analyzed by transmission electron
microscopy and ultraviolet–visible (UV–Vis) spectroscopy to be round, about 17–26 nm in size and E
g = 2.10 eV. 相似文献
11.
Mesoporous SiO2–TiO2 was synthesized by the sol–gel method using Si(OC2H5)4, Ti(OC2H5)4, and stearyltrimethylammonium chloride. By using acetylacetone as the capping agent of Ti(OC2H5)4, homogeneous SiO2–TiO2 composite was obtained. Spherical mesoporous SiO2–TiO2 was also synthesized by the sol–gel method using W/O emulsion under microwave irradiation. The specific surface area of these
mesoporous SiO2–TiO2 materials decreased when the Ti/Si molar ratio was higher than 0.1, which indicated that Ti was homogeneously distributed
in mesoporous SiO2 matrix at Ti/Si ≦ 0.1. The photocatalytic activity of mesoporous SiO2–TiO2 materials was investigated by the degradation of methylene-blue in water under UV light irradiation. Mesoporous SiO2–TiO2 was effective for the adsorption–decomposition of methylene-blue. 相似文献
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13.
H. Bensouyad D. Adnane H. Dehdouh B. Toubal M. Brahimi H. Sedrati R. Bensaha 《Journal of Sol-Gel Science and Technology》2011,59(3):546-552
We have studied structural and optical properties of thin films of TiO2, doped with 5% ZnO and deposited on glass substrate (by the sol–gel method). Dip-coated thin films have been examined at
different annealing temperatures (350–450 °C) and for various layer thicknesses (89–289 nm). Refractive index, porosity and
energy band gap were calculated from the measured transmittance spectrum. The values of the index of refraction are in the
range of 1.97–2.44, the porosity is in the range of 0.07–0.46 and the energy band gap is in the range of 3.32–3.43. The coefficient
of transmission varies from 50 to 90%. In the case of the powder of TiO2, doped with 5% ZnO, and aged for 3 months in ambient temperature, we have noticed the formation of the anatase phase (tetragonal
structure with 20.23 nm grains). However, the undoped TiO2 exhibits an amorphous phase. After heat treatments of thin films, titanium oxide starts to crystallize at the annealing temperature
350 °C. The obtained structures are anatase and brookite. The calculated grain size, depending on the annealing temperature
and the layer thickness, is in the range of 8.61–29.48 nm. 相似文献
14.
Ibrahim H. Mutlu Maharram Z. Zarbaliyev Ferhat Aslan 《Journal of Sol-Gel Science and Technology》2009,50(3):271-274
In this study we describe the preparation of Ga2Se3 semiconductor compound thin films by sol–gel method for different crystal formation temperatures. The films were characterized
by X-ray diffraction analyses (XRD), UV–visible spectrometer, and scanning electron microscope (SEM). The XRD spectrum showed
that the formation of Ga2Se3 crystals were between 743 and 823 K. The thin film crystals that were formed at 773 K corresponded to the β phase and the
preferred crystal structure was monoclinic. The value of band gap from optical absorption spectra for the Ga2Se3 thin films was estimated to be about E
g ~ 2.56 eV. The thickness of the one-coat Ga2Se3 thin films, which was measured by a Spectroscopic Ellipsometer, was about ~200 nm. The average grain sizes of scattered particles
were within the limits between 200 and 500 nm. 相似文献
15.
CeO2/TiO2 nanocomposite was synthesized by particulate sol–gel method. The X-ray diffractogram shows the presence of cubic CeO2 and anatase TiO2 in the composite. The high resolution scanning electron micrographs reveal the nanoparticulate nature of the prepared composite. The composite absorbs UV light and exhibits near-band gap emission corresponding to TiO2 and deep level emission due to crystal defects. The Nyquist plot displays two semicircular arcs indicating the material heterogeneity. The physicochemical characteristics of the synthesized nanocomposite are in favour of its application as an ingredient of sunscreen formulations; under UV light the photocatalytic activity of CeO2/TiO2 composite, tested through the degradation of rhodamine B, is very much less than that by pristine anatase TiO2. Reduced adsorption of moisture by the nanocomposite is a possible reason for the observed very low photocatalytic activity. 相似文献
16.
17.
Mauro Francisco Pinheiro da Silva Heloisa Cristina de Jesus Fraga da Costa Eduardo Rezende Triboni Mário José Politi Paulo Celso Isolani 《Journal of Thermal Analysis and Calorimetry》2012,107(1):257-263
The synthesis and characterization of graphite oxide (GO), graphene (GS), and the composites: GS–CeO2 and GO–CeO2 are reported. This synthesis was carried out by mixing aqueous solutions of CeCl3·7H2O and GO, which yields the oxidized composite GO–CeO2. GO–CeO2 was hydrothermally reduced with ethylene glycol, at 120 °C, yielding the reduced composite GS–CeO2. GO, GS ,and the composites with CeO2 were characterized by CHN, TG/DTG, BET, XRD, SEM microscopy, FTIR, and Raman spectroscopy. The estimation of crystallite
size of CeO2 anchored on GO and on GS by Raman, XRD, and SEM agreed very well showing diameters about 5 nm. The role of particles of CeO2 coating carbon sheets of GO and GS was discussed. 相似文献
18.
Poonam Sharma Praveen Kumar Anjana Solanki Rohit Shrivastav Sahab Dass Vibha R. Satsangi 《Journal of Solid State Electrochemistry》2012,16(4):1305-1312
A visible-light sensitive bilayered photoanode of Fe–TiO2/Zn–Fe2O3 has been developed by spray pyrolytically depositing Zn–Fe2O3 layers onto predeposited Fe–TiO2 thin film on ITO substrate. Fe–TiO2/Zn–Fe2O3 photoelectrodes were characterized by XRD, Raman, AFM, UV-vis absorption spectroscopy. Photoelectrochemical properties of
bilayered Fe–TiO2/Zn–Fe2O3 photoelectrode were studied by Mott–Schottky curves and I–V characteristics. Bilayered Fe–TiO2/Zn–Fe2O3 photoelectrode was observed to possess much higher separation efficiency of photogenerated charge carriers and could generate
nine times better photocurrent density than pure Fe–TiO2. Solar to hydrogen conversion efficiency exhibited by this electrode was 0.77%. 相似文献
19.
Elisa Marenna Carmela Aruta Elza Bontempi Antonio Cassinese Paolo Colombi Laura E. Depero Pasquale Pernice Antonio Aronne 《Journal of Sol-Gel Science and Technology》2009,49(1):106-111
The morphological and electrical characterization of transparent nanostructured LiNbO3–SiO2 thin films synthesized by a novel sol–gel route is reported. Films annealed at different temperatures exhibit different size
of the nanocrystals, as demonstrated by Atomic Force Microscopy and Glancing Incidence X-ray diffraction. The dc electrical
measurements performed on planar devices reveal electrical bistability. A clear relationship between the electrical bistability
and the size of LiNbO3 nanocrystals embedded in the matrix is observed. 相似文献
20.
M. S. Bhuwaneswari L. Dimesso W. Jaegermann 《Journal of Sol-Gel Science and Technology》2010,56(3):320-326
Lithium intercalation materials are of special interest as cathodes in rechargeable batteries. An uncomplicated sol–gel process
has been used for the synthesis of Li–Co phosphates powders and, for the first time, of LiCoPO4 films. The powders were prepared from aqueous solutions, containing Li, Co and phosphate precursors to which acid citric
and ethylene glycol was added, during the drying process at 75 °C. The X-ray diffraction patterns of the prepared powders
confirmed the presence of LiCoPO4 with an olivine-like structure as main phase. The morphological investigations of the powder showed a platelet-like structure
with an average grain size of 0.75 μm. The films of LiCoPO4 were deposited onto ITO glass substrates with the combination of the dip-coating process under the same conditions. Finally,
the films were annealed in inert atmosphere at 300 °C. The morphological investigations reveal a smooth and homogeneous surface
of the prepared Li–Co phosphate films. The preliminary electrical investigation on the prepared LiCoPO4 films showed lithium ions electrochemical activity in the range 3.0–4.5 V. 相似文献