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.

Characterization and Photocatalytic Activity of FeVO4 Photocatalysts Synthesized via a Surfactant-Assisted Sol-Gel Method

2011 ◽  
Vol 197-198 ◽  
pp. 926-930
Author(s):  
Min Wang ◽  
Qiong Liu ◽  
Chen Zhi Jiang
Keyword(s):  
Photocatalytic Activity ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Gel Method ◽  
Sol Gel Method ◽  
Photodegradation Rate ◽  
Photocatalytic Activities ◽  
Xrd Patterns ◽  
Surfactant Assisted

FeVO4photocatalysts were synthesized via a surfactant-assisted sol-gel method and characterized with X-ray diffraction (XRD), scanning electron microsoope （SEM）and specific surface area (BET). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under visible light. The XRD patterns of no-surfactant-assisted, PEG-assisted, CTAB-assisted and SDS-assisted FeVO4, indicate that diffraction peaks can be well indexed as triclinc FeVO4. And the crystalline sizes of samples were evaluated as 113, 69, 66, 76 nm for FVO, FVO-PEG, FVO-CATB and FVO-SDS respectively.The addition of surfactant woul greatly affect the morphology of FeVO4photocatalysts, which can lead to different photocatalytic activities between them. In the experimental conditions used, the PEG-assisted FeVO4product had a much higher photocatalytic activity (the photodegradation rate was about 77% or so in 14h) than the other three products.

Photocatalytic Activity of Transition Metal Doped Strontium Titanate Nanomaterial

2013 ◽  
Vol 700 ◽  
pp. 71-74
Author(s):  
Rui Ma ◽  
Wen Jie Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Strontium Titanate ◽  
Degradation Rate ◽  
Sol Gel ◽  
Slight Variation ◽  
Photocatalytic Activities ◽  
Method Effects ◽  
Degradation Activity ◽  
Metal Doped

Ce, Nd and Gd doped strontium titanate nanomaterial was prepared by a sol-gel method. Effects of transition metals doping on photocatalytic activities of the prepared materials were studied. The pure strontium titanate had photocatalytic degradation activity of 31.0%. The maximum degradation rate happened at Ce content of 20% and nearly 32.5% of the initial methyl orange was degraded on the material after 30 min of irradiation. Although there was a slight variation of photocatalytic degradation rate with the increasing Nd doping content, the materials doped with Nd had lower photocatalytic activity compared with pure strontium titanate. Nearly all the samples doped with Gd in the range up to 30% had much lower activity that the pure strontium titanate.

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.

Preparation and Characterization of Diatomite Supported Cu-Doped TiO2 Photocatalysts

2013 ◽  
Vol 853 ◽  
pp. 73-78
Author(s):  
Yan Xi Deng ◽  
Chuan Chuan Liu ◽  
Guang Yang
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Sol Gel ◽  
Methylene Blue Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photocatalytic Activities ◽  
Blue Solution

Diatomite supported Cu-doped TiO2 photocatalysts were synthesized by sol-gel method and characterized by X-ray diffraction (XRD), SEM and UV-vis diffuses reflectance of spectroscopy (DRS). The photocatalytic activity was evaluated by photocatalytic degradation of methylene blue solution under visible light irradiation. The results show that TiO2/diatomite ratio had a great influene on their photocatalytic activities. All prepared Cu-TiO2/diatomite had a better photocatalytic activities in comparison with Cu-TiO2 and the Cu-TiO2(30)/diatomite had higher photocatalytic activity than others. The photocatalytic degradation of methylene blue is due to the breaking of the chormophoric group, rather than the simple decoloration.

The Preparation of the Magnetically Separated Cu Doped TiO2 by Coating-Calcining Method

2011 ◽  
Vol 197-198 ◽  
pp. 857-860
Author(s):  
Han Yu Chen ◽  
Bao Shan Zhao ◽  
Zhao Hui Li
Keyword(s):  
Photocatalytic Activity ◽  
Sol Gel ◽  
Reaction System ◽  
The Novel ◽  
X Ray Diffraction ◽  
Preparation Conditions ◽  
Methylene Orange ◽  
Sol Gel Process ◽  
Photocatalytic Activities ◽  
Coating Procedure

In this paper, a magnetic hollow fly ash microsphere(MHFM) was prepared by citrate sol-gel method and the Cu doped TiO2nanopowder were prepared by sol-gel process at which the novel magnetic Cu-doped TiO2photocatalyst (M-Cu/TiO2) was prepared by coating-calcining process. The crystal phase and morphology of M-Cu/TiO2were investigated by Scanning electron microscopy(SEM), X-ray diffraction(XRD), The photocatalytic activities of the prepared photocatalyst under different preparation conditions were evaluated by the degradation of methyl orange (MO). Results showed that these TiO2photocatalysts were highly efficient for the destruction of methylene orange in water. In addition, the multi-coating procedure made it possible to effectively control the physical properties of TiO2layer such as the coating thickness, amount of TiO2and photocatalytic activity. The floating catalyst made by this method could also be separated easily from the reaction system. And the multilayer film has higher photocatalytic activity than TiO2film under visible light irradiation.

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.

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.

scholarly journals Hydrothermal Synthesis of Iodine-Doped Nanoplates with Enhanced Visible and Ultraviolet-Induced Photocatalytic Activities

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Jiang Zhang ◽  
Zheng-Hong Huang ◽  
Yong Xu ◽  
Feiyu Kang
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Oxygen Vacancies ◽  
Diffuse Reflectance Spectroscopy ◽  
Synergetic Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Photocatalytic Activities

The iodine-doped Bi2WO6(I-BWO) photocatalyst was prepared via a hydrothermal method using potassium iodide as the source of iodine. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The photocatalytic activity of I-BWO for the degradation of rhodamine B (RhB) was higher than that of pure BWO and I2-BWO regardless of visible light (>420 nm) or ultraviolet light (<400 nm) irradiation. The results of DRS analysis showed that the I-BWO and I2-BWO catalysts had narrower band gaps. XPS analysis proved that the multivalent iodine species including I0and were coadsorbed on the defect surface of Bi2WO6in I-BWO. The enhanced PL intensity revealed that a large number of defects of oxygen vacancies were formed by the doping of iodine. The enhanced photocatalytic activity of I-BWO for degradation of RhB was caused by the synergetic effect of a small crystalline size, a narrow band gap, and plenty of oxygen vacancies.

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