scholarly journals The effect of sintering temperature on mesoporous structure of WO3 doped TiO2 powders

2018 ◽  
Vol 50 (1) ◽  
pp. 123-132
Author(s):  
Srdjan Petrovic ◽  
Ljiljana Rozic ◽  
Stevan Stojadinovic ◽  
Bosko Grbic ◽  
Rastko Vasilic ◽  
...  
Keyword(s):  
Calcination Temperature ◽  
Lattice Strain ◽  
Sintering Temperature ◽  
Anatase Phase ◽  
Sol Gel ◽  
Hydrothermal Process ◽  
Mesoporous Structure ◽  
Physical Analysis ◽  
Doped Tio2 ◽  
X Ray

In this study, WO3 doped TiO2 powders were synthesized via sol-gel method combined with a hydrothermal process. The effect of sintering temperature on mesoporous structure and catalytic activities of these powders were investigated. The physical analysis via X-ray diffraction indicates that prepared samples are a mixture of anatase and rutile TiO2 phases. X-ray peak analysis is used to evaluate the crystallite size and lattice strain by the Williamson-Hall analysis. Considering all the reflections of the anatase phase the lattice strain ranging from c = 9.505 to c = 9.548 is calculated, suggesting that microstrain decreases when calcination temperature increases. N2 adsorption-desorption analysis shows that the surface area and pore volume decrease with increasing temperature and that WOx-TiO2 powders primarily consist of mesopores. Sintering temperature induced a change in textural properties causing a systematic shift towards larger mesopores. Simultaneously, photoactivity in decolorization of methyl orange increases with increasing calcination temperature up to 700?C, followed by significant decrease with its further increase.

Preparation of Mesoporous Magnetic TiO2/CoFe2O4 Photocatalysts Using Ionic Liquid as Template Agent

2013 ◽  
Vol 345 ◽  
pp. 201-204 ◽  
Author(s):  
Kai Wang ◽  
Lan Bo Di ◽  
Li Juan Zhang ◽  
Gui Fu Dong ◽  
Xiu Ling Zhang
Keyword(s):  
Phase Transition ◽  
Methylene Blue ◽  
Ionic Liquid ◽  
Photocatalytic Activity ◽  
Calcination Temperature ◽  
Sol Gel ◽  
Mesoporous Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bet Analysis

A simple sol-gel method using 1-butyl-3-methylimidazoliun tetrafluoroborate ([C4MIM]BF4) ionic liquid as template agent was used to prepared mesoporous magnetic TiO2/CoFe2O4photocatalysts (denoted as IL-TiO2/CoFe2O4). The photocatalysts were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis. The results showed that well crystallized anatase TiO2in IL-TiO2/CoFe2O4photocatalysts could be obtained when the calcination temperature was as low as 200 °C, and the phase transition temperature from anatase to rutile was increased to 800 °C. BET analysis showed that IL-TiO2/CoFe2O4was mesoporous structure. The photocatalytic activity of the samples was evaluated by photocatalytic degradation of methylene blue (MB). The results showed that photocatalytic activity of IL-TiO2/CoFe2O4was 6 times higher than that of TiO2/CoFe2O4when a low calcination temperature of 350 °C was used.

scholarly journals The Effects of Manganese Dopant Content and Calcination Temperature on Properties of Titania-Zirconia Composite

2021 ◽  
Vol 21 (4) ◽  
pp. 882
Author(s):  
Muhamad Imam Muslim ◽  
Rian Kurniawan ◽  
Mokhammad Fajar Pradipta ◽  
Wega Trisunaryanti ◽  
Akhmad Syoufian
Keyword(s):  
Calcination Temperature ◽  
Sol Gel ◽  
Diffraction Method ◽  
Dopant Content ◽  
Doped Tio2 ◽  
X Ray ◽  
Specular Reflectance ◽  
Vis Spectroscopy ◽  
Mn Doped ◽  
Mn Dopant

The effects of dopant content and calcination temperature on Mn-doped TiO2-ZrO2 structure and properties were successfully investigated. Composite of Mn-doped titania-zirconia was synthesized by sol-gel method. Titanium(IV) isopropoxide was used as the precursor of TiO2, while zirconiapowder was used as another semiconductor. MnCl2∙4H2O was used as the source of dopant in this study. Various amounts of manganese were incorporated into TiO2-ZrO2 and calcination was performed at temperatures of 500, 700 and 900 °C. Synthesized composites were characterized by Fourier-transform infrared spectroscopy (FTIR), specular reflectance UV-Vis spectroscopy (SR UV-Vis), X-ray diffraction method (XRD) and scanning electron microscopy equipped with X-ray energy dispersive spectroscopy (SEM-EDX). The results showed that Mn-doped TiO2-ZrO2 with the lowest bandgap (2.78 eV) was achieved with 5% of Mn dopant and calcined at 900 °C, while Mn-doped TiO2-ZrO2 with the highest bandgap (3.12 eV) was achieved with 1% of Mn dopant content calcined at 500 °C.

scholarly journals Cu-Doped TiO2: Visible Light Assisted Photocatalytic Antimicrobial Activity

2018 ◽  
Vol 8 (11) ◽  
pp. 2067 ◽  
Author(s):  
Snehamol Mathew ◽  
Priyanka Ganguly ◽  
Stephen Rhatigan ◽  
Vignesh Kumaravel ◽  
Ciara Byrne ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Density Functional ◽  
Anatase Phase ◽  
Sol Gel ◽  
Light Irradiation ◽  
Health Concern ◽  
Bacterial Inactivation ◽  
Doped Tio2 ◽  
X Ray

Surface contamination by microbes is a major public health concern. A damp environment is one of potential sources for microbe proliferation. Smart photocatalytic coatings on building surfaces using semiconductors like titania (TiO2) can effectively curb this growing threat. Metal-doped titania in anatase phase has been proven as a promising candidate for energy and environmental applications. In this present work, the antimicrobial efficacy of copper (Cu)-doped TiO2 (Cu-TiO2) was evaluated against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) under visible light irradiation. Doping of a minute fraction of Cu (0.5 mol %) in TiO2 was carried out via sol-gel technique. Cu-TiO2 further calcined at various temperatures (in the range of 500–700 °C) to evaluate the thermal stability of TiO2 anatase phase. The physico-chemical properties of the samples were characterized through X-ray diffraction (XRD), Raman spectroscopy, X-ray photo-electron spectroscopy (XPS) and UV–visible spectroscopy techniques. XRD results revealed that the anatase phase of TiO2 was maintained well, up to 650 °C, by the Cu dopant. UV–vis results suggested that the visible light absorption property of Cu-TiO2 was enhanced and the band gap is reduced to 2.8 eV. Density functional theory (DFT) studies emphasize the introduction of Cu+ and Cu2+ ions by replacing Ti4+ ions in the TiO2 lattice, creating oxygen vacancies. These further promoted the photocatalytic efficiency. A significantly high bacterial inactivation (99.9999%) was attained in 30 min of visible light irradiation by Cu-TiO2.

Preparation and Photocatalytic Activity of TiO2/Tourmaline Composite Catalyst

2013 ◽  
Vol 800 ◽  
pp. 464-470 ◽  
Author(s):  
Wei Chao Liu ◽  
Huan Yan Xu ◽  
Tian Nuo Shi ◽  
Li Cheng Wu ◽  
Ping Li
Keyword(s):  
Photocatalytic Activity ◽  
Sintering Temperature ◽  
Anatase Phase ◽  
Sol Gel ◽  
Rutile Phase ◽  
Composite Catalyst ◽  
Nanosized Particles ◽  
X Ray Diffraction ◽  
Composite Photocatalyst ◽  
X Ray

TiO2/tourmaline composite photocatalyst was prepared by sol-gel method using tetrabutyl orthotitanate (Ti (OC4H9)4) as a precursor. As a comparison, pure TiO2 was prepared at the same experimental conditons without the addition of tourmaline. The obtained composite photocatalyst was characterized by X-Ray diffraction (XRD) and scanning electron microscope (SEM) and its photocatalytic activity was also investigated through the photodiscoloration of methyl orange (MO) under UV irradiation. The XRD results indicated that, in the composite photocatalyst, TiO2 existed in the form of anatase and rutile, with the sintering temperature and tourmaline content increasing, the anatase phase trended to the transformation to rutile phase. The SEM results revealed that the nanosized particles of TiO2 were well dispersed and immobilized on the surface of tourmaline, especially for the sample with 2% tourmaline content. Compared with pure TiO2, the composite photocatalyst exhibited a higher photocatalytic activity. When the pure TiO2 was used as the photocatalyst, the MO discoloration ratio only reached 55%. However, the MO discoloration ratio could approach 100% in presence of TiO2/tourmaline composit photocatalyst under the same conditions. The effects of tourmaline content and sintering temperature on the photocatalytic activity of the composite were studied in this work and the results suggested that the sample with 2% tourmaline content and sintered at the temperature of 550°C exhibited the best photocatalytic activity. Finally, the possible mechanism for the photodiscoloration of MO was put forward.

Cu Doped TiO2: Visible Light Assisted Photocatalytic Antimicrobial Activity and High Temperature Anatase Stability

2018 ◽  
Author(s):  
Snehamol Mathew ◽  
Priyanka Ganguly ◽  
Stephen Rhatigan ◽  
Vignesh Kumaravel ◽  
Ciara Byrne ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Density Functional ◽  
Anatase Phase ◽  
Sol Gel ◽  
Chemical Properties ◽  
Light Irradiation ◽  
Health Concern ◽  
Bacterial Inactivation ◽  
X Ray

Indoor surface contamination by microbes is a major public health concern. A damp environment is one potential sources for microbe proliferation. Smart photocatalytic coatings on building surfaces using semiconductors like titania (TiO<sub>2</sub>) can effectively curb this growing threat.<b> </b>Metal-doped titania in anatase phase has been proved as a promising candidate for energy and environmental applications. In this present work, the antimicrobial efficacy of copper (Cu) doped TiO<sub>2 </sub>(Cu-TiO<sub>2</sub>) was evaluated against <i>Escherichia coli</i> (Gram-negative) and <i>Staphylococcus aureus</i> (Gram-positive) under visible light irradiation. Doping of a minute fraction of Cu (0.5 mol %) in TiO<sub>2 </sub>was carried out <i>via</i> sol-gel technique. Cu-TiO<sub>2</sub> further calcined at various temperatures (in the range of 500 °C – 700 °C) to evaluate the thermal stability of TiO<sub>2</sub> anatase phase. The physico-chemical properties of the samples were characterised through X-ray diffraction (XRD), Raman spectroscopy, X-ray photo-electron spectroscopy (XPS) and UV-visible spectroscopy techniques. XRD results revealed that the anatase phase of TiO<sub>2</sub> was maintained well, up to 650 °C, by the Cu dopant. UV-DRS results suggested that the visible light absorption property of Cu-TiO<sub>2 </sub>was enhanced and the band gap is reduced to 2.8 eV. Density functional theory (DFT) studies emphasises the introduction of Cu<sup>+</sup> and Cu<sup>2+</sup> ions by replacing Ti<sup>4+</sup> ions in the TiO<sub>2</sub> lattice, creating oxygen vacancies. These further promoted the photocatalytic efficiency. A significantly high bacterial inactivation (99.9%) was attained in 30 mins of visible light irradiation by Cu-TiO<sub>2</sub>.

Structure and Morphology Properties of Nanosized La0.75K0.05Ba0.05Sr0.15MnO3 Manganite

2020 ◽  
Vol 860 ◽  
pp. 106-111
Author(s):  
Dhawud Sabilur Razaq ◽  
Budhy Kurniawan ◽  
Ikhwan Nur Rahman ◽  
Dicky Rezky Munazat
Keyword(s):  
Bond Length ◽  
Crystallite Size ◽  
Sintering Temperature ◽  
Bond Angle ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Phase Purity ◽  
X Ray ◽  
Structure And Morphology ◽  
Scanning Electron

Nanosized La0.75K0.05Ba0.05Sr0.15MnO3 manganite have been synthesized using sol-gel method. Afterwards, the samples were sintered at eight different temperature ranging from 650 to 1000 °C. Phase purity, crystal structure and the morphology of the sample have been examined using X-Ray Diffractometer (XRD) and Scanning Electron Microscope. It has been found that different higher sintering temperature greatly affect the phase purity and crystallite size of the sample. Regardless of the sintering temperature, all the samples crystallized in rhombohedral structure with R-3c space group. The crystallite size of the samples is found to increase from 41.59 nm up to 73.42 nm as the sintering temperature increases. Further analysis from XRD result shows that sintering temperature also affect the average Mn-O bond length and Mn-O-Mn bond angle of the sample. The average Mn-O bond length is found to increase while the average Mn-O-Mn bond angle tends to decrease as sintering temperature increases. SEM measurement shows that various grain size ranging from ~100 nm up to ~ 350 nm exists in all the sample regardless the sintering temperature.

Sintering AlN Ceramics Below 1500°C with MgO-CaO-Al2O3-SiO2 Glass Addition

2007 ◽  
Vol 336-338 ◽  
pp. 1868-1871 ◽  
Author(s):  
Cheng Fu Yang ◽  
Chien Min Cheng ◽  
Ho Hua Chung ◽  
Chao Chin Chan
Keyword(s):  
Sintering Temperature ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Dielectric Characteristics ◽  
Sintering Aid ◽  
Glass Addition ◽  
X Ray ◽  
Crystal Phases ◽  
Diffraction Patterns ◽  
Scanning Electron

5~15 wt% MgO-CaO-Al2O3-SiO2 (MCAS, fabricated by sol-gel method) glass is used as the sintering aid of AlN ceramics. The sintering is proceeded from 1350oC~1550oC, scanning electron microscope is used to observe the sintered morphologies and X-ray diffraction pattern are used to confirm the crystal structures. From the SEM observations, as 10wt% and 15wt% MCAS is added, AlN ceramics can be densified at 1500oC and 1450oC, which are much lower than the before studies were. From the X-ray diffraction patterns, the crystal phases of MCAS-AlN ceramics are AlN, Al2O3, and cordierite phases. In this study, the dielectric characteristics of MCAS-AlN ceramics are also developed as a function of MCAS content and sintering temperature.

Characterization of Titanium Dioxide Nanopowder Synthesized by Sol Gel Grinding Method

2012 ◽  
Vol 626 ◽  
pp. 425-429 ◽  
Author(s):  
N.N. Hafizah ◽  
Mohamed Zahidi Musa ◽  
Mohamad Hafiz Mamat ◽  
M. Rusop
Keyword(s):  
Electron Microscopy ◽  
Anatase Phase ◽  
Sol Gel ◽  
Precursor Concentration ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grinding Method ◽  
Fesem Micrographs ◽  
Scanning Electron

In this study, TiO2nanopowder was synthesized via a sol-gel grinding method. The effects of TiO2precursor concentration of TiO2nanopowder were investigated. The TiO2nanopowder obtained were characterized using X-ray diffraction (XRD), Raman spectroscopy and field emission scanning electron microscopy (FESEM) for their structural properties. From the calculation of the crystallite size in XRD, the size of the nanoparticles obtained is 49.55 nm at the highest TiO2precursor concentration. In contrast, at the lower concentration of 0.4 molar give the cryatallite size of 12.84 nm. Further, XRD and Raman spectrum results confirmed the TiO2nanopowder obtain composed of only anatase phase. The FESEM micrographs of TiO2nanopowder also were discussed in this paper.

Synthesis, Characterization and Photocatalytic Activity of Nb-Doped TiO2 Nanoparticles

2012 ◽  
Vol 455-456 ◽  
pp. 110-114 ◽  
Author(s):  
Xuan Dong Li ◽  
Xi Jiang Han ◽  
Wen Ying Wang ◽  
Xiao Hong Liu ◽  
Yan Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Doped Tio2 ◽  
X Ray ◽  
Vis Spectroscopy

Nb-doped TiO2 powders with different concentrations of Nb have been synthesized by a sol-gel method and characterized by a series of technologies including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. The photocatalytic activity of Nb-doped TiO2 is evaluated by degradation efficiency of methyl orange in aqueous solution. The results indicate that the photocatalytic activity of Nb-doped TiO2 synthesized with a Nb/Ti molar ratio of 5% is higher than that of TiO2 under the visible light.

A comparative study of doped and un-doped sol-gel TiO2 and P25 TiO2 (photo)electrodes

2007 ◽  
Vol 55 (12) ◽  
pp. 153-160 ◽  
Author(s):  
Y. Pooarporn ◽  
A. Worayingyong ◽  
M. Wörner ◽  
P. Songsiriritthigul ◽  
A.M. Braun
Keyword(s):  
Indium Tin Oxide ◽  
Electrochemical Impedance ◽  
Anatase Phase ◽  
Sol Gel ◽  
Oxide Glass ◽  
Electrochemical Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Titanium Dioxide Films ◽  
Indium Tin Oxide Glass

Doped and undoped titanium dioxide films have been deposited on indium tin oxide glass using the sol-gel technique. The percentage of rutile in the prepared TiO2, calcined at 823 K and determined by X-ray diffraction, was 23% compared to 24% of rutile in P25-TiO2. Cerium doped TiO2 showed mainly the anatase phase, as characterised by both X-ray diffraction and Raman spectroscopy. The electrochemical and photoelectrochemical properties of the films were studied by cyclic voltammetry and electrochemical impedance spectroscopy. The (photo)electrochemical characteristics of the different films are reported and discussed.

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