Influence of Ag Doping on the Crystal Structure and Photocatalytic Activity of FeVO4

2011 ◽  
Vol 197-198 ◽  
pp. 919-925 ◽  
Author(s):  
Min Wang ◽  
Qiong Liu

Silver (Ag+) doped iron (III) vanadate (FeVO4) samples are prepared by the precipitation method and then characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy(XPS). The photocatalytic activity under visible light is evaluated by photocatalytic degradation of methyl orange (MO) in the solution. The results show that both FeVO4 and Ag+ doped FeVO4 samples are triclinic, the later have different surface morphology, and some needle-shaped materials appear in the later. From XPS, there are more Fe2+ ions in Ag+ doped FeVO4 sample than that in FeVO4 one without Ag+. It indicates that Ag+ doping can increase the density of the surface oxygen vacancies of catalysts, which can act as electron traps promoting the electron-hole separation and then increase the photo-activity. The decoloration rate after Ag+ doping against methyl orange solution can reach about 81%, and be more about 20% than that of pure FeVO4.

2014 ◽  
Vol 1004-1005 ◽  
pp. 962-966
Author(s):  
Lu Sheng Chen ◽  
Huan Shuang Zhang ◽  
Shu Lian Liu ◽  
Wen Hua Song ◽  
Chao Liu ◽  
...  

In this work, samarium and antimony (Sm–Sb) codoped tin oxide (SnO2) films have been successfully prepared on titanium (Ti) substrate by a facile sol gel method. The samples were characterized by X–ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The composite film materials were used as anode for the electro-degradation of methyl orange solution. Two effective factors of electro–catalytic properties namely, the content of Sm in the SnO2 samples and the calcination temperature, have been optimized based on the electro-degradation experiments. A moderately calcination temperature of 873 K and 1.0% Sm doping owned the best performance. The smaller grain sizes and optical band gap of the SnO2 by introduction of the Sm improved electro-catalytic activity.


2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Zhang Shu ◽  
Shulin Wang

Using the prepared particles of 10 nm–25 nm as magnetic core, we synthesized / composite particles with as the shell by homogeneous precipitation. Their structure and morphology were characterized by X-ray diffraction (XRD), X-Ray photoelectron spectroscopy (XPS), transmission electronic microscopy (TEM), Fourier transform infrared spectra (FTIR), and vibration-sample magnetometer (VSM). We show that with urea as precipitant transparent and uniform coating of ca.3 nm thick on , particles can be obtained. The composite particles have better dispersivity than the starting materials, and exhibit super-paramagnetic properties and better chemical adsorption ability with saturated magnetization of 33.5 emu/g. Decoloration experiment of methyl orange solution with / composite suggested that the highest decoloration rate was 94.33% when the pH of methyl orange solution was 1.3 and the contact time was 50 minutes. So this kind of / composite particle not only has super-paramagnetic property, but also good ability of chemical adsorption.


2011 ◽  
Vol 396-398 ◽  
pp. 854-857 ◽  
Author(s):  
Zheng Hua Xiao ◽  
Jun Bo Zhong ◽  
Jian Zhang Li ◽  
Wei Hu

It has been found that the photocatalytic activity of ZnO toward the decolorization of Methyl Orange solution can be greatly improved by loading Ag on the surface of ZnO using a photodeposition method. The photocatalysts were characterized by X-ray diffraction(XRD), UV-Vis diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy(XPS), respectively. 0.5%Ag/ZnO demonstrates 2.13 times the photocatalytic activity of pure ZnO.


2012 ◽  
Vol 518-523 ◽  
pp. 775-779 ◽  
Author(s):  
Dong Dong Tan ◽  
De Fu Bi ◽  
Peng Hui Shi ◽  
Shi Hong Xu

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.


2012 ◽  
Vol 455-456 ◽  
pp. 110-114 ◽  
Author(s):  
Xuan Dong Li ◽  
Xi Jiang Han ◽  
Wen Ying Wang ◽  
Xiao Hong Liu ◽  
Yan Wang ◽  
...  

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.


Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2594 ◽  
Author(s):  
Luning Xuan ◽  
Yunlin Fu ◽  
Zhigao Liu ◽  
Penglian Wei ◽  
Lihong Wu

A Fe3+-doped SiO2/TiO2 composite film (Fe3+-doped STCF) was prepared on a wood surface via a sol–gel method to improve its photocatalytic activity and hydrophobicity. The structure of the composite film was analyzed by Fourier Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity toward degradation of methyl orange and its hydrophobic nature were investigated. The results showed that the composite film was anatase TiO2 crystal form, and the addition of Fe3+ ions and SiO2 enhanced the diffraction peaks for the anatase crystal form. The photocatalytic activity of the wood coated with the composite film was enhanced. The highest degradation percentage was at 1 wt % Fe3+ (40.37%), and the degradation ability of the wood towards methyl orange solution was further improved under acidic conditions. In addition, the composite film was hydrophobic, and the hydrophobic property was enhanced as the immersion time in the sol increased. The wood surface coated with Fe3+-doped STCF exhibited strong hydrophobicity and photocatalytic activity, which could effectively prevent moisture from adhering to the surface and degrade organic pollutants; thus, the modified wood surface had good self-cleaning function.


2012 ◽  
Vol 178-181 ◽  
pp. 645-648
Author(s):  
Yan Lu ◽  
Jun Bo Zhong ◽  
Jian Zhang Li ◽  
Wei Hu

It has been found that the photocatalytic activity of Bi2O3toward the decolorization of Methyl Orange solution can be greatly improved by loading Ag on the surface of Bi2O3using a photodeposition method. The photocatalysts were characterized by X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy and surface photovoltage spectroscopy (SPS), respectively. 0.5%Ag/Bi2O3possesses the best photocatalytic activity.


2013 ◽  
Vol 829 ◽  
pp. 594-599 ◽  
Author(s):  
Saham Sharifat ◽  
Hossein Zolgharnein ◽  
Abdolghader Hamidifalahi ◽  
Mahnaz Enayati-Jazi ◽  
Entesar Hamid

A new in-situ precipitation technique is introduced in this study to prepare hydroxyapatite/titania nanocomposites. This technique provides a better control over the microstructures and phase compositions of nanocomposites. The structure and surface morphology of hydroxyapatite/titania nanocomposite were characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy and scanning electron microscopes. The photocatalytic activity of hydroxyapatite/titania nanocomposite was evaluated by photocatalytic decolorization of methyl orange in aqueous solution as a model pollutant under UV-irradiation. X-ray diffraction and Fourier transform infrared results indicated that hydroxyapatite and anatase (TiO2) were the major crystalline phases. There had been no reaction between hydroxyapatite and titania compounds. Based on the SEM images, the overall morphology of the samples indicates that there exists a distribution of small particles and large agglomerates.The hydroxyapatite/titania nanocomposite exhibited high photocatalytic activity hydroxyapatite/titania nanocomposite under UV-irradiation. After 8 h of irradiation by UV-irradiation, over 80% of methyl orange solution (5 mg L-1) was decolorized with 1 gL-1 of the photocatalyst. Since this process does not require the addition of hydrogen peroxide and uses UV-irradiation in this study are environmentally friendly method to decolorize azo dye.


2011 ◽  
Vol 356-360 ◽  
pp. 558-564
Author(s):  
Xiao Wei Yuan ◽  
Xue Guo ◽  
Dan Dan Yang ◽  
Li Juan Wang ◽  
Mei Ling Cheng ◽  
...  

Hollow cubic TiO2particles were synthesized using cubic Cu2O particles as hard templates, and the hydrolysis of tetrabutyl titanate (TBOT). The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-Vis spectrometer, respectively. The results show that the prepared TiO2is composed of anatase TiO2, and has a stronger absorption in the range of 300-400nm wavelengths in its UV-Vis spectroscopy. Experiments were carried out using a methyl orange solution as a model to evaluate the photocatalytic activity of hollow cubic TiO2particles. The effects of catalyst dosage, initial concentration and pH of methyl orange solution on the degree of photodegradation have been investigated. It’s found that the hollow cubic TiO2particles have a good photocatalytic property. And the degradation rate of the methyl orange, after methyl orange solution (5mg/L) containing hollow cubic TiO2particles (0.5g/L) is irradiated by 125W ultraviolet light for 120 minutes, is 95%.


2011 ◽  
Vol 374-377 ◽  
pp. 855-858
Author(s):  
Jin Fen Niu ◽  
Bing Hua Yao ◽  
Jia Wei

High photocatalytic activity TiO2 photocatalysts were prepared using titanium(IV) sulphate as the precursor by liquid-phase precipitation method. X-ray diffraction and TEM were employed to characterize the morphology, structure of the photocatalysts. Photocatalysic activity of TiO2 prepared by this method was investigated using photocatalytic degradation of methyl red (MR) under UV and visible-light (VL) irradiation as the model reaction. The results indicated that the highest catalytic activity TiO2 catalyst was prepared under 700°C calcination for 4h. The optimum decoloration rate of simulated dyeing wastewater for MR reached to 95% and 98% after UV and visible-light illuminating for 30 min and 140min respectively.


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