scholarly journals A Comparison of Different A-, A-B-, and B-Site Incorporated in (Ba0.5Sr0.5)TiO3 on Photocatalytic Application

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Tassanee Tubchareon ◽  
Rachan Klaysri ◽  
Piyasan Praserthdam
Keyword(s):  
Methylene Blue ◽  
Structural Modification ◽  
Oxygen Vacancies ◽  
Sol Gel ◽  
Lattice Oxygen ◽  
Photocatalytic Decolorization ◽  
Chemisorbed Oxygen ◽  
Photocatalytic Application ◽  
Sol Gel Process ◽  
A Site

The structural modification of Ba0.5Sr0.5TiO3 (BST) nanocatalyst was successfully synthesized via sol-gel process. The BST catalyst was modified by A-site (A-BST), A-B-site (A-B-BST), and B-site (B-BST) in order to investigate the effect of structurally modified BST catalyst for photocatalytic decolorization of methylene blue. The structurally modified BST catalysts can increase the nonradiation energy such as phonon energy compared to that of BST one. The partial incorporation of the A-BST catalyst was evidenced by the higher-ordered structure by increasing number of Ti4+ ions and the lattice oxygen. The A-B-BST and A-BST catalysts were given more electron-transfer in the TiO6 than that of BST and B-BST catalysts, respectively. The A-B-BST catalyst promoted the oxidation of the lattice oxygen by holes capturing to form the chemisorbed oxygen, presenting the highest photobleaching activity of methylene blue. On the other hand, more oxygen vacancies recombination of BST catalyst compared to that of structurally modified BST catalysts presented the reduction of photocatalytic activity.

Preparation and Photocatalytic Activity of TiO2/Opal Composite

2013 ◽  
Vol 668 ◽  
pp. 13-16
Author(s):  
Qing Shan Li ◽  
Biao Zhan ◽  
Wei Hong ◽  
Guang Zhong Xing
Keyword(s):  
Methylene Blue ◽  
Uv Light ◽  
Sol Gel ◽  
Tetrabutyl Titanate ◽  
Methylene Blue Solution ◽  
Photocatalytic Decolorization ◽  
Uv Light Irradiation ◽  
Photocatalytic Activities ◽  
Blue Solution ◽  
Gel Technique

Opal as a carrier, tetrabutyl titanate as a titanium source, TiO2 loaded on opal was prepared by sol-gel technique. The photocatalysts were characterized by XRD, TEM and UV-VIS absorption spectrum. Their photocatalytic activities were examined by the photocatalytic decolorization of methylene blue solution under UV light irradiation. The effects of calcination temperature, the amount of TiO2 loading and pH on photocatalytic activities were discussed. The results show that TiO2 supported on opal induced enhancement of photocatalytic decolorization rant and TiO2 doping is about 30 wt. % with 92.15% of decolorization rate at 700°C.

ZnO-SiO2/Laponite Photocatalyst: Kinetic Study on Photocatalytic Decolorization of Methylene Blue

2014 ◽  
Vol 896 ◽  
pp. 541-544
Author(s):  
Is Fatimah ◽  
N. Nunani Yuyun
Keyword(s):  
Methylene Blue ◽  
Energy Dispersive Spectrometry ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photocatalytic Decolorization ◽  
Uv Visible ◽  
Gel Preparation ◽  
Adsorption Desorption

ZnO-SiO2/Laponite was prepared by sol-gel preparation procedure consit of SiO2 pillarization to laponite followed by ZnO dispersion by using zinc acetate as precursor. The obtained material was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), diffuse reflectance UV-Visible (DRUV-Vis) and N2 adsorption-desorption analysis. The photocatalytic performance of the amterial in methylene blue decolorization was also investigated. Compared with ZnO-SiO2 nanoparticles, it is concluded that ZnO-SiO2/Laponite possess higher photocatalytic activity which obey Temkin isotherm model.

Relaxor Behavior in Ba0.8Sr0.2TiO3/ZrO2 Heterostructured Thin Films

2012 ◽  
Vol 1454 ◽  
pp. 89-96 ◽  
Author(s):  
Santosh K. Sahoo ◽  
H. Bakhru ◽  
Sumit Kumar ◽  
D. Misra ◽  
Y. N. Mohapatra ◽  
...  
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Oxygen Vacancies ◽  
Sol Gel ◽  
Single Layer ◽  
Relaxor Behavior ◽  
Bst Thin Films ◽  
Si Substrates ◽  
Sol Gel Process ◽  
Loss Maximum

ABSTRACTBa0.8Sr0.2TiO3 (BST) thin films and Ba0.8Sr0.2TiO3/ZrO2 heterostructured thin films have been successfully fabricated on Pt/Ti/SiO2/Si substrates by a sol-gel process. The dielectric properties of these films were measured as a function of temperature in the frequency range of 1 kHz to 1 MHz. It is clearly observed that the dielectric peaks exist and shift to high temperature with the increase of frequency indicating the presence of relaxor-type behavior in the films. Also it is seen that one dielectric peak is observed in single layer BST thin films whereas two dielectric peaks are observed in BST/ZrO2 heterostructured thin films due to the presence of two dielectric layers having different band gap energies. The variation of peak temperature Tm, corresponding to dielectric loss maximum, with frequency and fitting to Arrhenius law gives activation energy of 1.24 eV which is very close to the activation energy of oxygen vacancies in BaTiO3. Hence, oxygen vacancies are the active defects which are contributing to the relaxation process in these films.

Synthesis and Characterization of Ag-Decorated TiO2 Nanoparticles for Photocatalytic Application

2021 ◽  
Vol 10 (4) ◽  
pp. 13-18
Author(s):  
K. Balachandran ◽  
G. Vijayakumar ◽  
S. Mageswari ◽  
A. Preethi ◽  
M.S. Viswak Senan
Keyword(s):  
Grain Size ◽  
Tio2 Nanoparticles ◽  
Sol Gel ◽  
Tem Analysis ◽  
Photocatalytic Application ◽  
Visible Spectra ◽  
Sol Gel Process ◽  
Titanium Tetra Isopropoxide ◽  
Ft Ir

TiO2 nanoparticles (TiO2) and Ag-doped TiO2 nanocomposites (Ag-TiO2) were synthesized by the Sol-Gel process using titanium tetra isopropoxide as TiO2 and AgNO3 as Ag precursors, respectively. The synthesized nanocomposites were characterized by XRD, SEM, TEM, FT-IR, and UV­-Visible analysis. The XRD results show that Ag doping increases the grain size from 22 nm to 36 nm. From the UV-Visible spectra, the redshift in absorbance was observed, which indicates the increase in grain size and it reduces the bandgap. The TEM analysis shows that all the particles are exhibited in the nanometer range. The synthesized nanoparticles show good photocatalytic activity, and they decompose the methyl orange dye within 5 hours.

Microstructure and Properties of A-Site Doping Bi4-xYxTi3O12 Ferrroelectric Thin Films

2015 ◽  
Vol 815 ◽  
pp. 171-175
Author(s):  
Hong Cheng Liu ◽  
Wei Jun Zhang ◽  
Xiao Chen Zhang ◽  
Qian Yu ◽  
Jue Wang
Keyword(s):  
Thin Films ◽  
Coercive Field ◽  
Remnant Polarization ◽  
Bismuth Titanate ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Ferroelectric Thin Films ◽  
Phase Development ◽  
Sol Gel Process ◽  
A Site

s. Yttium-substituted bismuth titanate (Bi4-xYxTi3O12, BYT) thin films were deposited on the (111)Pt/Ti/SiO2(100) substrates by a modified Sol-Gel process and studied in this work in terms ofY3+-modified microstructure and phase development as well as ferroelectric properties. With the aid of the fist-principle, the position of Y3+substitution for Bi3+on the microstructure of BYT was studied.The phase change in the formation of BYT crystalline and the effect of Y3+substitution for Bi3+on the microstructure of BYT was studiedbyXRD. The results showed that the optimal properties of the obtained BYT ferroelectric thin films werex:0.6. The ferroelectric properties of the films were also investigated. When the Y-substituted contentxwas equal to 0.6, the remnant polarization was the largest. The remnant polarization 2Prvalue was equal to 16.02μC/cm2and the coercive fieldEcvalue was 88 kV/cm.

Phase structure and thermal evolution in coatings and powders obtained by the sol-gel process: Part I. ZrO2−11.3 mol% Y2O3

1997 ◽  
Vol 12 (2) ◽  
pp. 493-500 ◽  
Author(s):  
P. C. Rivas ◽  
M. C. Caracoche ◽  
J. A. Martínez ◽  
A. M. Rodríguez ◽  
R. Caruso ◽  
...  
Keyword(s):  
Oxygen Vacancies ◽  
Thermal Evolution ◽  
Sol Gel ◽  
Correlation Spectroscopy ◽  
Cubic Phase ◽  
Perturbed Angular Correlation Spectroscopy ◽  
Heating And Cooling ◽  
Sol Gel Process ◽  
Fast Movement ◽  
Zirconia Powders

Yttria-stabilized cubic zirconia powders and coatings produced by the sol-gel method have been investigated by Perturbed Angular Correlation Spectroscopy (PAC). Results indicate that the metastable cubic phase is retained during heating and cooling cycles. The hyperfine interaction that describes this cubic phase, once crystallized, exhibits two components in a constant ratio of 4 : 1. The components represent different vacancy configurations. For the fast movement of oxygen vacancies starting at 750 °C, which is reflected by the damping of the hyperfine pattern, an activation energy of 0.96 eV was determined.

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