EFFECTS OF Eu-DOPING SITE ON STRUCTURAL AND PHOTOLUMINESCENT PROPERTIES OF CaTiO3 PARTICLES

2011 ◽  
Vol 01 (02) ◽  
pp. 215-221 ◽  
Author(s):  
GUANPING HUANG ◽  
WEN DONG ◽  
LIANG FANG ◽  
FENGANG ZHENG ◽  
MINGRONG SHEN
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Blue Shift ◽  
Charge Compensation ◽  
Spectra Analysis ◽  
Light Region ◽  
Compensation Mechanisms ◽  
Photocatalytic Activities ◽  
Absorbance Spectra ◽  
The Eu

In this paper, Eu3+ -doped CaTiO3 (CTO) nanoparticles were prepared by a sol-gel method. Three different charge compensation mechanisms were realized by substituting Eu ion at different sites. (i) Ca site substitution with Ca vacancy compensation (CTO-A); (ii) Ti site substitution with O vacancy compensation (CTO-B); (iii) simultaneous substitution at both Ca and Ti sites with self-compensation (CTO-AB). Strongly related to the site substitution, the photoluminescent (PL) intensities were increasing in the sequence of CTO-B > CTO-AB > CTO-A. The absorbance spectra analysis of pure CTO nanoparticles showed absorption in the UV light region, while the absorption of Eu -doped CTO samples exhibited the blue shift owing to the presence of Eu3+ . Moreover, the photocatalytic activities of samples for decomposing dyes were reverse to the sequence of PL intensities. The PL properties and photocatalytic activity of the Eu3+ -doped CTO nanoparticles were thus discussed in detail from the viewpoints of the microstructures and charge transfer-related processes.

Synergistic Effect of Eu3+ and Sm3+ Co-Doping on Photocatalytic Activity of TiO2 Nanoparticles

2011 ◽  
Vol 197-198 ◽  
pp. 891-894 ◽  
Author(s):  
Cheng Zhi Jiang ◽  
Xu Dong Lu
Keyword(s):  
Photocatalytic Activity ◽  
Synergistic Effect ◽  
Sol Gel ◽  
Blue Shift ◽  
Nano Particles ◽  
Absorption Profile ◽  
Co Doping ◽  
The Matrix ◽  
Co Doped ◽  
The Eu

Pure TiO2, Eu3+and Sm3+co-doping TiO2composite nanoparticles have been prepared by sol-gel method and characterized by the techniques such as XRD, SEM and DRS. The photocatalytic degradation of methylene blue (MB) in aqueous solution was used as a probe reaction to evaluate their photocatalytic activity. The matrix distortion of TiO2nano-particles increases after co-doping of Eu3+and Sm3+and a blue-shift of the absorption profile are clearly observed. The results show that co-doping of Eu3+and Sm3+inhibits the phase transformation of TiO2from anatase to rutile, decreases the diameter of TiO2nano-particles and significantly enhance the photocatalytic activity of TiO2. The Eu3+and Sm3+co-doped into TiO2nano-particles exert a synergistic effect on their 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.

scholarly journals Effects of Bi3+ Ion-Doped on the Microstructure and Photoluminescence of La0.97Pr0.03VO4 Phosphor

2021 ◽  
Vol 6 (3) ◽  
pp. 191-198
Author(s):  
Hao-Long Chen ◽  
Hung-Rung Shih ◽  
Sean Wu ◽  
Yee-Shin Chang
Keyword(s):  
White Light ◽  
Emission Intensity ◽  
Sol Gel ◽  
Blue Shift ◽  
Light Emitting ◽  
Light Region ◽  
Chromaticity Coordinates ◽  
Ion Doping ◽  
Ion Contents ◽  
Cie Chromaticity

The objective of this paper is to enhance the emission intensity of La0.97Pr0.03VO4 single-phased white light emitting phosphor. The Bi3+ ion-doped La0.97Pr0.03VO4 single-phased white light emitting phosphors are synthesized using a sol-gel method. The structure and photoluminescence properties of (La0.97-yBiy)Pr0.03VO4 (y = 0-0.05) phosphor are also examined. The XRD results show that the structure of La0.97Pr0.03VO4 phosphors with different concentrations of Bi3+ ion doping keeps the monoclinic structure. The SEM results show that the phosphor particles become smoother when the Bi3+ ion is doped. The excitation band for La0.97Pr0.03VO4 phosphor exhibits a blue shift from 320 nm to 308 nm as the Bi3+ ion contents are increased. The maximum emission intensity is achieved for a Bi3+ ion content of 0.5 mol%, which is about 30% greater than that with no Bi3+ ion doped. The CIE chromaticity coordinates are all located in the near white light region for different Bi3+ ion-doped La0.97Pr0.03VO4 phosphors.

Self-Cleaning TiO2/SiO2 Thin Film Prepared by a Simple Sol-Gel Method

2014 ◽  
Vol 804 ◽  
pp. 157-160
Author(s):  
Wen Xiu Liu ◽  
Jun Na Xu ◽  
Jun Zhang ◽  
Xue Mei Liu ◽  
Wen Bin Cao
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Sulfate Solution ◽  
Ultraviolet Region ◽  
X Ray Diffraction ◽  
High Concentration ◽  
Titanyl Sulfate ◽  
Glass Substrates ◽  
Light Region ◽  
Vis Spectroscopy

TiO2 thin films were prepared on SiO2-coated glass substrates using sols deriving from high concentration titanyl sulfate solution by the spin-coating technique. The calcined films were characterized by X-ray diffraction, UV-Vis spectroscopy, scanning electron microscopy. The film exhibited high transmittance in the visible light region and high absorption in the ultraviolet region. The contact angle of SiO2/TiO2 decreased to below 5° under 30 min of UV light irradiation and can sustain for 1 weeks.

Charge compensation mechanisms in favor of the incorporation of the Eu 3+ ion into the ZnO host lattice

2018 ◽  
Vol 537 ◽  
pp. 296-300 ◽  
Author(s):  
M. Baira ◽  
A. Bekhti-Siad ◽  
K. Hebali ◽  
H. Bouhani-Benziane ◽  
M. Sahnoun
Keyword(s):  
Charge Compensation ◽  
Host Lattice ◽  
Compensation Mechanisms ◽  
The Eu

Preparation, Characterization and Photocatalysis Properties of Ultrafine Perovskite-Type LaCoO3

2011 ◽  
Vol 197-198 ◽  
pp. 935-942
Author(s):  
Xia Fu ◽  
Yang Chen ◽  
Gao Qi Yu ◽  
Chao Yu ◽  
Hou Zhi Wang ◽  
...  
Keyword(s):  
Supercritical Fluid ◽  
Mixed Oxides ◽  
Uv Light ◽  
Sol Gel ◽  
Raw Material ◽  
Supercritical Fluid Drying ◽  
Photocatalytic Activities ◽  
Ft Ir ◽  
Drying Technology ◽  
Perovskite Type

Using La2O3and Co(NO3)2•6H2O as raw material, ultrafine perovskite-type oxides LaCoO3was prepared by Supercritical Fluid Drying Technology and Sol-Gel method. The prepared materials’ crystal structure and morphology were characterized by TG-DTA、XRD、FT-IR and TEM. The photocatalytic activity of ultrafine LaCoO3powders was evaluated by degradation of methyl orange (MO) solution under 15W UV light irradiation. The results show: At 250°C , the amorphous ultrafine La-Co particles with the size less than 10 nm can be obtained by Supercritical Fluid Drying Technology. At 850°C , the size of the particles increased to 15-35nm, the nanocrystalline LaCoO3had a perfect rhombohedral perovskite structure. At 900°C , the crystalline phases of the lanthanum-cobalt mixed oxides were LaCoO3and La2O3, and the amorphous component is Co2O3, the presence of lanthanum affects the crystallization of cobalt oxides. The LaCoO3has excellent photocatalytic activities and 100% MO solution was decolorized only after 4h.

Synthesis of Composite TiO2/Natural Cotton Cellulose Nanofiber with Photocatalytic Property

2014 ◽  
Vol 665 ◽  
pp. 393-396
Author(s):  
Qiu Yan Liu ◽  
Jing Li ◽  
Jun Cao ◽  
Chao Rong Li
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Organic Pollutant ◽  
Sol Gel ◽  
Photocatalytic Property ◽  
Important Application ◽  
Anatase Structure ◽  
Uv Light Irradiation ◽  
Photocatalytic Activities ◽  
Hydrothermal Methods

TiO2/NCCN nanocomposites have been prepared by sol-gel and hydrothermal methods. Firstly, the NCCN was prepared by electrospinning technology, then the amorphous TiO2films were coated on the surface of the NCCN by a sol-gel method, and TiO2(anatase structure) nanoparticles could be fixed on the surface of NCCN by a hydrothermal method to get higher photocatalysis efficiency. The photocatalytic activities indicate that the TiO2/NCCN nanocomposites exhibited a good photocatalytic activity for photodegradation of methylthionine chloride (MO) solution under UV light irradiation, leading to an important application in photodegradation of organic pollutant.

scholarly journals REMOVAL OF NORFLOXACIN BY TiO2-SBA-15 PHOTOCATALYST

2020 ◽  
Vol 58 (3A) ◽  
pp. 13
Author(s):  
Nguyễn Thị Thu Trang ◽  
Trần Quang Vinh ◽  
Nguyễn Thành Đồng ◽  
Phạm Tuấn Linh ◽  
Nguyễn Viết Hoàng ◽  
...  
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Surface Areas ◽  
Pluronic P123 ◽  
Adsorption Capacities ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Adsorption Desorption ◽  
Synthesized Materials

Ordered SBA-15 mesoporous silica support was synthesized by a sol-gel method using triblock copolymer Pluronic P123 and immobilized with different amounts of photocatalyst TiO2. The synthesized composites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption-desorption isotherms. The synthesized materials possessed specific surface areas SBET of 768 m2/g, 544 m2/g, 421 m2/g and 333 m2/g at the TiO2:SiO2 ratio of 0, 0.25, 1.0 and 5.0, respectively. The adsorption capacities and photocatalytic activities under UV light irradiation of these materials were evaluated for Norfloxacin degradation. Experimental results indicate that the highest activity was observed on the sample with TiO2:SiO2 ratio of 1.

scholarly journals Luminescence Properties of Eu- and Mg-Codoped Sol-Gel SiO2 Glasses

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Martin O. Onani ◽  
Paul Mushonga ◽  
Lehlohonolo F. Koao ◽  
Francis B. Dejene
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Silica Matrix ◽  
Luminescence Spectroscopy ◽  
X Ray Diffraction ◽  
Light Excitation ◽  
Uv Lamp ◽  
Hydrolysis Of ◽  
Excited Luminescence ◽  
The Eu

A series of SiO2 nanostructures codoped with Eu3+; Mg2+ ions were obtained by a sol-gel method. The gels synthesized by the hydrolysis of Si(OC2H5)4, Eu(NO3)3·6H2O, and Mg(NO3)2 were heated in air at 600°C for 2 hours. Firstly, the total amount of Eu3+ ions was varied from 0 to 2.0 mol% to investigate the effect of self-damping, while in the second case, the Eu3+ ions were kept constant in the experiment at 0.5 mol% total doping and Mg2+ ions varied. The samples were characterized by X-ray diffraction, TEM, EDS, and UV lamp-excited luminescence spectroscopy. The Eu3+ ions were homogeneously dispersed in the silica and interacting with the small (1–5 nm) amorphous silica matrix. Strong red emissions located at 614 nm and 590 nm for doped and codoped SiO2 were observed from the UV light excitation at room temperature. The composition of around 1.25 mol% Eu3+ gave highest emission intensity. SiO2; Mg2+ ions portray strongly enhanced emissions due to energy transfer from Mg2+ to Eu3+, which is due to radiative recombination. An increase in luminescence intensity was observed as the Mg2+-to-Eu3+ ratio increased for the range investigated. The results show Eu3+ ion is located inside or at the surface of disordered SiO2 nanoparticles.

scholarly journals Photocatalitic Properties of Tio2 and ZnO Nanopowders / Tio2 un Zno Nanopulveru Fotokatalitiskās Īpašības

2013 ◽  
Vol 50 (4) ◽  
pp. 48-55 ◽  
Author(s):  
L. Grigorjeva ◽  
J. Rikveilis ◽  
J. Grabis ◽  
Dz. Jankovica ◽  
C. Monty ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Vapour Deposition ◽  
Uv Light ◽  
Sol Gel ◽  
Grain Morphology ◽  
Rutile Phase ◽  
Physical Vapour Deposition ◽  
Grain Sizes ◽  
Absorbance Spectra

Abstract Photocatalytic activity of TiO2 and ZnO nanopowders is studied depending on the morphology, grain sizes and method of synthesizing. Photocatalysis of the prepared powders was evaluated by degradation of the methylene blue aqueous solution. Absorbance spectra (190-100 nm) were measured during exposure of the solution to UV light. The relationships between the photocatalytic activity and the particle size, crystal polymorph phases and grain morphology were analyzed. The photocatalytic activity of prepared TiO2 nanopowders has been found to depend of the anatase-to-rutile phase ratio. Comparison is given for the photocatalytic activity of ZnO nanopowders prepared by sol-gel and solar physical vapour deposition (SPVD) methods

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