scholarly journals Rare Earth FreeZn3V2O8Phosphor with Controlled Microstructure and Its Photocatalytic Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Hom Nath Luitel ◽  
Rumi Chand ◽  
Toshio Torikai ◽  
Mitsunori Yada ◽  
Takanori Watari
Keyword(s):  
Photocatalytic Activity ◽  
Rare Earth ◽  
Quantum Yield ◽  
Sol Gel ◽  
Emission Spectra ◽  
Host Lattice ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Visible Absorption ◽  
Pl Emission

Microsphere of rare earth free phosphor,Zn3V2O8, with broadband yellowish white emission was synthesized by combustion route and compared with the hydrothermal, sol-gel, and solid state reaction methods. The phosphor samples were characterized by X-ray diffraction and scanning electron microscopy. UV-visible absorption and photoluminescence (PL) emission and excitation spectra were investigated for these phosphors.Zn3V2O8phosphor containing 10 mol% of H3BO3flux exhibited enhanced PL emission showing broadband from 450 nm to 750 nm. Effect of stoichiometry of Zn and V on the host lattice and its effect on the PL emission spectra were studied. Series of Mg3V2O8,Ca3V2O8, and Sr3V2O8phosphors were also synthesized and compared to theZn3V2O8phosphor in terms of PL emission and internal quantum yield, and it was found thatZn3V2O8is the most efficient phosphor among the other phosphors studied with quantum yield of 60%. The visible light irradiated photocatalytic activity of these phosphors was investigated and it was found that the hydrothermalZn3V2O8exhibited enhanced activity.

IMPROVEMENT OF PHOTOCATALYTIC ACTIVITY OF TiO2 VIA COMBINED ROUTE OF METAL DOPING AND SURFACE ACIDIFICATION

2006 ◽  
Vol 13 (04) ◽  
pp. 429-438 ◽  
Author(s):  
YONG LUAN ◽  
PINGFENG FU ◽  
XUEGANG DAI
Keyword(s):  
Photocatalytic Activity ◽  
Sol Gel ◽  
Emission Spectra ◽  
Favorable Effect ◽  
Infrared Analysis ◽  
X Ray Diffraction ◽  
Metal Doping ◽  
Ultraviolet Light Irradiation ◽  
Photocatalytic Activities ◽  
Metal Doped

In the present work, a combined route involving first doping of iron or neodymium ions via sol–gel method followed by acidification of the metal-doped TiO 2 particles for the improvement of the photocatalytic capability of TiO 2 was reported. The obtained metal-doped/acidified TiO 2 photocatalysts were thoroughly characterized by X-ray diffraction, Fourier transform infrared analysis, and photoluminescence emission spectra. At the same time, their photocatalytic activities were evaluated in simulant photodegradation of methylene blue (MB). The results based on these characterizations showed that not only a rutile layer formed on the surface of original TiO 2 particles after surface cladding, but also the doped Fe or Nd ion had a favorable effect on suppression of the electron–hole recombination in the titania under ultraviolet light irradiation. Furthermore, the photocatalytic activity of the material obtained by Fe doping and acidification was substantially improved in comparison to the untreated TiO 2. However, the sample prepared from Nd -doping and acidification of TiO 2 showed decreased capability relative to the untreated TiO 2 in degradation of MB under similar conditions. Finally, the reason why the photocatalytic activities of the obtained catalysts are sensitive to the metal-doping was discussed in details.

Synthesis and Luminescent Properties of Gd2MoO6:Eu3+

2015 ◽  
Vol 15 (10) ◽  
pp. 7765-7769 ◽  
Author(s):  
Sook Hyun Kwon ◽  
Byung Kee Moon ◽  
Jung Hyun Jeong ◽  
Hyun Kyoung Yang ◽  
Jung Hwan Kim
Keyword(s):  
Charge Transfer Band ◽  
Sol Gel ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Light Emitting ◽  
Diffraction Patterns ◽  
White Light Emitting Diodes ◽  
Electron Microscope Image

A series of 6 mol% Eu3+ doped Gd2MoO6 samples were prepared by using the sol–gel method. The X-ray diffraction patterns of the samples confirmed their monoclinic structure after they were annealed at 1300 °C, and a scanning electron microscope image revealed closely packed particles. The excitation spectra showed that the intensity of the excitation band decreased and the charge transfer band shifted from 370 to 350 nm with decreasing sintering temperature. The emission spectra are dominated by the hypersensitive forced electron dipolar transition 5D0 → 7F2 at 612 nm. The as synthesized phosphor can be used as a red phosphor in white light emitting diodes.

Titania-Phosphotungstic Acid Nanocomposites Dispersed Homogeneously in Mesopores as the Recyclable Photocatalyst

2010 ◽  
Vol 152-153 ◽  
pp. 202-207
Author(s):  
Hua Lan Zhou ◽  
Sha Wu ◽  
Zhong Zou ◽  
Qin Qin ◽  
Wen Jian Shi
Keyword(s):  
Photocatalytic Activity ◽  
Phosphotungstic Acid ◽  
Sol Gel ◽  
Particle Growth ◽  
Tio2 Particle ◽  
Composite Catalyst ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Calcination Process ◽  
Transmission Electron

Heterogeneous photocatalytic materials, titania–phosphotungstic acid nanocomposites in the mesopores of SBA-15 (TiO2-H4PW12O40/SBA15) were prepared by sol–gel method. Compositions and structures of the nanocomposites were characterized by X-ray diffraction (XRD), UV-visible absorption spectroscopy and transmission electron microscopy (TEM). Uniform mesoporous SBA15 consisting of long-range channels provides the immobilization of titania-phosphotungstic acid nanocomposites. The photocatalytic activity of the prepared TiO2-H4PW12O40/SBA15 powders was evaluated from an analysis of the photocatalytic degradation of methyl orange. The results indicated that photocatalytic activity increased with the amount of H4PW12O40 from 0% to 10% and decreased when the amount of H4PW12O40 was above 10%. It is due to the synergetic reaction of H4PW12O40 and TiO2. However, much more H4PW12O40 can occupy the active center of TiO2. TiO2 can inhibit the decomposition of H4PW12O40 in the TiO2-H4PW12O40/SBA15 composites. On the other hand, H4PW12O40 repressed the TiO2 particle growth during calcination process. The composite catalyst also had the advantage of easily being recovered and reused.

The Preparation and Photocatalytic Activity of SWNTs Doped ZnO/TiO2 Compound Films

2010 ◽  
Vol 97-101 ◽  
pp. 1611-1615 ◽  
Author(s):  
Qing Wang ◽  
Xin Li Li ◽  
Wei Nie ◽  
Yong Mei Xia ◽  
Jian Feng Dai
Keyword(s):  
Photocatalytic Activity ◽  
Absorption Spectra ◽  
Sol Gel ◽  
Composite Films ◽  
Wavelength Region ◽  
Tio2 Films ◽  
X Ray Diffraction ◽  
Sol Gel Process ◽  
Doped Zno ◽  
Walled Carbon Nanotubes

The ZnO/TiO2 composite films were deposited over glass using spin coating technique by sol-gel process. Single-walled carbon nanotubes (SWNTs) were used to modify the ZnO/TiO2 films successfully in this paper. The structure and composition of the ZnO/TiO2 composite and SWNTs doped ZnO/TiO2 composite were characterized by X-ray diffraction (XRD). The morphology of samples was characterized by scanning electron microscopy (SEM). The photocatalytic activity was investigated by photocatalytic degradation of aqueous methyl orange under ultraviolet (UV) radiation. The UV-vis absorption spectra of the ZnO/TiO2 films and SWNTs doped ZnO/TiO2 films in the wavelength region 200~800 nm were obtained. The results indicate that the SWNTs addition can decrease the grain size of ZnO/TiO2, which can enhance the photocatalytic activity. UV-vis absorption spectra of SWNTs-ZnO/TiO2 showed obvious blue shifts compared with ZnO/TiO2. The optimal amount of doping SWNTs is 1% according to this research. The enhanced mechanism of the SWNTs for the photocatalytic activity in ZnO/TiO2 films was analyzed in this article.

Preparation and Photocatalytic Property of TiO2/NiFe2O4 Composite Photocatalysts

2012 ◽  
Vol 518-523 ◽  
pp. 775-779 ◽  
Author(s):  
Dong Dong Tan ◽  
De Fu Bi ◽  
Peng Hui Shi ◽  
Shi Hong Xu
Keyword(s):  
Photocatalytic Activity ◽  
Sol Gel ◽  
Photocatalytic Property ◽  
Methyl Orange Solution ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
X Ray ◽  
Uv Illumination ◽  
Composite Photocatalysts ◽  
Orange Solution

The TiO2/NiFe2O4 (TN) composite nanoparticles with different mass ratios of NiFe2O4 to TiO2 were prepared via sol-gel method. X-ray diffraction was used to characterize the phase structure of TN. The results indicated that adulterating a smidgen of NiFe2O4 into the TiO2 (about 0.1%) can promote the phase transformation of TiO2, however, when the doping amount of NiFe2O4 surpasses 1%, the introduction of NiFe2O4 can inhibit the growth of TiO2 crystal grain and reduce the size of TiO2 crystal grain. The degradation experiment of methyl orange solution under UV illumination (253.7 nm) showed that the content of NiFe2O4 in the TN was higher, the photocatalytic activity of TN was worse, and the 0.1% TiO2/NiFe2O4 calcined at 400 °C presented the best photocatalytic activity.

Synthesis and Characterization of Y2O3:Eu3+ Film Derived by Sol-Gel Processing

2007 ◽  
Vol 336-338 ◽  
pp. 593-596
Author(s):  
Chun Yang ◽  
Jun Ying Zhang ◽  
Hai Bing Feng ◽  
Wei Chang Hao ◽  
Tian Min Wang
Keyword(s):  
Raw Materials ◽  
Sol Gel ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Dip Coating ◽  
Organic Additive ◽  
Excitation Spectra ◽  
Excitation Peak ◽  
Close Relationship ◽  
Dip Coating Technique

Y2O3:Eu3+ thin film was synthesized by sol-gel method with inorganic salt raw materials, and the crystal structure and luminescent properties were investigated. By adding organic additive to the sol, a homogeneous film with high luminescent intensity could be obtained by dip-coating technique on the surface of alumina sheet and quartz glass. Structures of the films were studied by XRD and SEM. The excitation spectra of the films showed a wide excitation peak from 200nm to 260nm, and the emission spectra had a strongest emission peak at 611nm which revealed a close relationship with the calcining temperature.

Visible-Light-Induced Photocatalytic Activity of Boron-Doped BiVO4

2014 ◽  
Vol 809-810 ◽  
pp. 890-894
Author(s):  
Dan Li ◽  
Lian Wei Shan ◽  
Gui Lin Wang ◽  
Li Min Dong ◽  
Wei Li ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Reflectance Spectroscopy ◽  
Scheelite Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Boron Doped

Boron-BiVO4 samples were synthesized by sol-gel method. They were characterized by UV-vis diffuse reflectance spectroscopy, X-ray diffraction. Photocatalytic activity of the obtained BiVO4 samples was investigated through degrading methylene blue (MB). The results reveal that boron-BiVO4 catalysts have monoclinic scheelite structure. The BiVO4 and Co-BiVO4 photocatalysts were responsive to visible light. Co-BiVO4 photocatalyst showed higher photocatalytic activity than pure BiVO4, resulting in the significantly improved efficiency of degradation of MB.

Nanocrystalline α-Fe2O3: A Superparamagnetic Material for w-LED Application and Waste Water Treatment

2021 ◽  
Author(s):  
Mahesh Gaidhane ◽  
Deepak Taikar ◽  
Pravin Gaidhane ◽  
Kalpana Nagde
Keyword(s):  
Photocatalytic Activity ◽  
Waste Water Treatment ◽  
Sol Gel ◽  
Average Particle Size ◽  
Emission Spectra ◽  
Broad Emission Band ◽  
Average Particle ◽  
X Ray ◽  
Prepared Material ◽  
Cie Chromaticity

Abstract Nanocrystalline α-Fe2O3 is synthesized by sol-gel technique. The prepared nanomaterial was characterized by X-ray diffraction (XRD), SEM, TEM, Fourier Transform Infrared (FTIR) spectroscopy, Vibrating Sample Magnetometry (VSM) and photoluminescence (PL) techniques. X-ray powder diffraction analysis confirmed the formation of α-Fe2O3. Electron microscopy showed spherical morphologies with an average particle size of 30-40 nm. The magnetic property of the prepared material was studied by VSM at room temperature. VSM study shows superparamagnetic nature of the synthesized nanoparticles. Photoluminescence (PL) emission spectra show intense broad emission band centered at 570 nm with 393 nm excitation indicating its usefulness for w-LED application. The CIE-chromaticity color coordinates of prepared material were calculated. The photocatalytic activity of the α-Fe2O3 nanoparticles was analyzed and the nanopowder exhibited good photocatalytic activity for the removal AO7 from its aqueous solution.

Facile Fabrication and Efficient Photocatalytic Activity of 3D-Ordered Macroporous ZnO Film

2012 ◽  
Vol 509 ◽  
pp. 259-265
Author(s):  
Hao Xie ◽  
Tao Zeng ◽  
Xue Lai Wang ◽  
Xiu Jian Zhao
Keyword(s):  
Photocatalytic Activity ◽  
Solar Light ◽  
Latex Film ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Zno Film ◽  
Visible Absorption ◽  
Simulated Solar Light ◽  
Facile Fabrication ◽  
Ordered Macroporous

Three-dimensionally (3D) ordered macroporous ZnO film was fabricated on a glass slide by layer-by-layer depositing and hydrolysis of Zn(CH3COO)2using 3D-ordered latex film as template followed by calcination at 450 °C for 2 h to remove the organic template. The as-prepared 3D-ordered macroporous ZnO film was characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), diffusive reflectance UV-visible absorption spectra (DRUV-VIS), photoluminescence (PL), and photoelectrochemical measurement. Its photocatalytic activity was evaluated by the photocatalytic degradation of crystal violet (CV) aqueous solution at ambient temperature under the irradiation of simulated solar light. It was found that the 3D-ordered ZnO film exhibits efficient photocatalytic activity for photodegradation of CV under the irradiation of simulated solar light.

Photocatalytically Active Cotton Fabrics Produced with Anatase Synthesized Using a Low-Temperature Sol-Gel Process

2018 ◽  
Vol 762 ◽  
pp. 408-412
Author(s):  
Raivis Eglītis ◽  
Gundars Mežinskis
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Sol Gel ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Sol Gel Process ◽  
Anatase Nanoparticles ◽  
Pre Treatment

In this work two different hydrosols were used to impregnate a commercially available cotton fabric with anatase nanoparticles to give it photocatalytic activity. To increase the activity, different pre-treatment methods were applied. The nanoparticle size was determined using dynamic light scattering and x-ray diffraction and the fabrics were examined using scanning electron microscopy. Photocatalytic activity was measured using the degradation of methyl-orange while irradiating the samples with UV light. The synthesis method allowed to produce anatase with an average particle size of 32 to 37 nm depending on the synthesis method used.

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