scholarly journals Synthesis and Characterization of Magnetic Nanosized / Composite Particles

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 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.


2019 ◽  
Author(s):  
Nur Tsalits Fahman Mughni

A Novel catalyst prepared from Indonesia bauxite was used as a catalyst for photo fenton degradation of methyl orange solution. This catalyst is more cheaper than Nafion-based catalyst and more greener than other synthesized catalysts. It is easily prepared from Indonesian natural resources. X-ray diffraction measurements provide structure and mineral compostion of bauxite, while XRF provides information on the composition of Fe by 18% by weight of bauxite mass. The presence of large amounts of Fe in bauxite acts as a catalyst in the decomposition of metyl orange. Testing of photo fenton activity to decompose metyl orange showed that indonesian bauxite had high catalytic activity, was able to decompose 99.4% metyl orange within 40 minutes on irradiation using an 8Watt UVC radiation source


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.


2019 ◽  
Vol 26 (1) ◽  
pp. 104-113 ◽  
Author(s):  
Xian-sheng Wang ◽  
Yu-duo Zhang ◽  
Qiao-chu Wang ◽  
Bo Dong ◽  
Yan-jia Wang ◽  
...  

AbstractZnO is modified by Cu2O by the process of precipitation and calcination. X-ray diffraction has shown that Cu2O/ZnO catalysts are made of highly purified cubic Cu2O and hexagonal ZnO. Scanning electron microscopy and transmission electron microscopy have shown that ZnO adhered to the surface of Cu2O. Due to the doping of Cu2O, the absorption range of the Cu2O/ZnO catalyst is shifted from the ultraviolet to the visible region due to diffuse reflection. X-ray photoelectron spectroscopy and photoluminescence spectra have confirmed that there is a substantial interaction between the two phases of the resultant catalyst. The degradation efficiency of Cu2O/ZnO on methyl orange solution is obviously enhanced compared to Cu2O and ZnO. The maximum degradation efficiency is 98%. The degradation efficiency is affected by the pH of the solution and initial concentration. After three rounds of recycling, the degradation rate is almost same. This shows a consistent performance of Cu2O/ZnO. The increase in catalytic ability is related to the lattice interaction caused by the doping of Cu2O.


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.


Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 660 ◽  
Author(s):  
Pierre G. Ramos ◽  
Clemente Luyo ◽  
Luis A. Sánchez ◽  
Enrique D. Gomez ◽  
Juan M. Rodriguez

In this work, well-designed zinc oxide-reduced graphene oxide (ZnO-rGO) nanorods (NRs) were synthesized by a hydrothermal method using electrospun ZnO-rGO seed layers. The ZnO-rGO seed layers were fabricated on fluorine-doped tin oxide (FTO) glass substrates through calcined of electrospun nanofibers at 400 °C in the air for 1 h. The nanofibers were prepared by electrospinning different spinning voltages and a spinning solution containing zinc acetate, polyvinyl pyrrolidone, and 0.2 wt% rGO. From a detailed characterization using various analytical techniques, for instance, X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), Raman spectroscopy, photoluminescence (PL), and X-ray photoelectron spectroscopy (XPS), the dependence of the structure, morphology, and optical properties of the ZnO-rGO NRs was demonstrated. The photocatalytic activities of ZnO-rGO nanorods were evaluated through the degradation of dye methyl orange (MO). The results show that the change of spinning voltages and the coupling of rGO with ZnO improved photodecomposition efficiency as compared to pure ZnO. The highest photocatalytic efficiency was obtained for the ZnO-rGO NRs prepared with a spinning voltage of 40 kV.


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.


Sign in / Sign up

Export Citation Format

Share Document