Synthesis, Characterization and Photocatalytic Property of Magnetic Titania Hollow Sphere Composite

2011 ◽  
Vol 298 ◽  
pp. 188-192
Author(s):  
Cong Zhang ◽  
Rong Hou ◽  
Hui Zhang

The magnetic anatase titania (TiO2) hollow spheres have been fabricated as magnetic photocatalyst by template (polystyrene)-sacrificed method, in which cobalt ferrite and titania was sequentially deposited on the surface of polystyrene spheres via coprecipitation and sol-gel process followed by calcinations. X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM) were employed to characterize the products, and the photocatalytic activities were evaluated by photodegradation of methyl orange (MO) under UV illumination. The results indicate that the as-prepared magnetic titania hollow spheres exhibit magnetic property and high photocatalytic activity.

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.


2021 ◽  
Vol 21 (10) ◽  
pp. 5143-5149
Author(s):  
Zhen Zhu ◽  
Wang-De Lin

This paper reports on a nanocomposite synthesized by sol–gel procedure comprising graphene sheets with hollow spheres of titanium dioxide (G/HS-TiO2) with varying weight percentages of graphene for the purpose of humidity sensors. The surface morphology of the nanocomposite was characterized using transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The structural properties were examined using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). The response to 12–80% RH at room temperature exhibited sensitivity (S = 135). However, the relative humidity range of 12–90% at room temperature exhibited higher sensitivity (S = 557). Sensors fabricated using the proposed nanocomposite exhibited high sensitivity to humidity, high stability, rapid response times, and rapid recovery times with hysteresis error of less than 1.79%. These results demonstrate the outstanding potential of his material for the monitoring of atmospheric humidity. This study also sought to elucidate the mechanisms underlying humidity sensing performance.


2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Sun Zhenya ◽  
Deng Yundi ◽  
Zhang Weiying

Composite ZnO/SnO2nanocrystalline particles (ZnO/SnO2) were synthesized by sol-gel method and with treatment of high pressure at 6 GPa. The crystallinity and the particle size of the prepared samples were analyzed by X-ray diffraction (XRD) spectroscopy. The results indicated that all the samples had the good crystallinity, and the particle size of ZnO and ZnO/SnO2decreased after high-pressure treatment. The infrared (IR) spectra showed that the distance of crystal lattice was shortened after high-pressure treatment, and the size distribution became more uneven afterSnO2doping. With the high-resolution transmission electron microscope (HRTEM), we got some morphology information and evidence to support the IR and XRD analysis results. The results of ultraviolet-visible absorption (UV-Vis) spectra showed that ZnO/SnO2might improve the photocatalytic property of the samples after high-pressure treatment.


2011 ◽  
Vol 76 (11) ◽  
pp. 1335-1346 ◽  
Author(s):  
Jing Wei ◽  
Xin Tan ◽  
Tao Yu ◽  
Lin Zhao

A series of copper-modified titanium dioxide (Cu/TiO2) nanoparticles were synthesized via one-step sol-gel method. The crystal structure and chemical properties were characterized using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The Cu/TiO2nanoparticles were applied to CO2photoconversion and the yield of formaldehyde was used to evaluate the photocatalytic performance. The optimum amount of copper modifying was 0.6 wt.% and the yield of formaldehyde was 946 μmol/gcatunder UV illumination for 6 h. 20 wt.% Cu/TiO2also performed a high photocatalytic activity, which yielded 433 μmol/gcatformaldehyde under UV illumination for 6 h.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Pham Van Viet ◽  
Cao Minh Thi ◽  
Le Van Hieu

Tin oxide nanoparticles (SnO2NPs) were prepared at low temperature by hydrothermal method. Synthesized SnO2NPs were confirmedviacharacterization techniques such as UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), and Transmission Electron Microscope (TEM). The synthesized nanoparticles were in the size of 3 nm and they have high photocatalytic activity. The result showed that SnO2NPs degraded 88.88% MB solution after 30 minutes of UV illumination and reached 90.0% for 120 minutes (2 hours) of UV illumination. Moreover, they degraded 79.26% MB solution after 90 minutes (1.5 hours) under assisted sunlight illumination.


2012 ◽  
Vol 512-515 ◽  
pp. 334-338 ◽  
Author(s):  
Tie Kun Jia ◽  
Fan Zhang ◽  
Xiao Feng Wang ◽  
Wei Min Wang

Zn-doped SnO2 seaflower like hierarchical architectures have been synthesized via a solvothermal synthesis route in the mixed solvents of ethanol and deionized water. The observations of field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) showed that Zn-doped SnO2 seaflower like hierarchical architectures were assembled by the nanowires. The preferential growth direction of nanowires was determined based on the analysis of high resolution transmission electron microscopy (HRTEM). The products were also characterized by X-ray diffraction (XRD) and X-photoelectron spectrum (XPS), and the results indicated that Sn4+ ions were successfully substituted by Zn2+. The photocatalytic activity of Zn-doped SnO2 seaflower like hierarchical architectures was evaluated by the degradation of RhB aqueous solution and the results showed that the product had high photocatalytic activity efficiency.


2013 ◽  
Vol 850-851 ◽  
pp. 156-159
Author(s):  
Xin Yan Wu ◽  
Wei Xiong

TiO2 nanosheets have been successfully synthesized via a simple sol-gel process. These nanostructures were characterized by transmission electron microscopy (TEM) and x-ray energy dispersive spectrometer (EDS). The sheet-shaped single-crystalline nanostructures are pure rutile-phase structure, with landscape dimension of 10-45 nm. EDS investigation confirms that the TiO2 nanosheets are only composed of Ti and O, and the atomic ration of Ti and O is close to 1:2. High photocatalytic activity might be expected for those TiO2 nanosheets due to their large surface area.


2014 ◽  
Vol 699 ◽  
pp. 245-250
Author(s):  
Afrouz Baharvand ◽  
Alias Mohd Yusof ◽  
Rusmidah Ali ◽  
Mohd Marsin Sanagi ◽  
Sheela Chandren ◽  
...  

Hollow anatase titania spheres have been synthesized using hydrothermally–prepared carbon spheres as the template. Here, the combination of hydrothermal process with sol–gel followed by calcination in air was done in order to obtain hollow anatase TiO2 spheres by utilizing fructose and tetrabutyl titanate (TBT) as the precursors. The structure and morphology of the products were characterized using various techniques, including Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermal gravimetric and differential thermal analysis (TG–DTA), scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). XRD showed that all peaks of TiO2 correspond to anatase crystalline phase. The BET surface area of the hollow spheres was about 22 m2g-1. The photocatalytic activity of the hollow anatase TiO2 was measured under UV light using γ-lindane as the target pollutant and was compared to commercially available TiO2.


2021 ◽  
Vol 33 (6) ◽  
pp. 1319-1324
Author(s):  
E.S. Kunarti ◽  
R. Roto ◽  
S. Sutarno ◽  
I.S. Budi ◽  
M. Mardiansyah

Magnetic photocatalyst of magnetite modified titania composite Fe3O4/TiO2 was prepared by co-precipitation and sol-gel methods followed by calcination at 450 ºC. The produced material was confirmed by XRD, FTIR spectrophotometer, vibrating sample magnetometer and transmission electron microscope. The solid material was tested as a photocatalyst for degradation of nitrobenzene under UV light irradiation. The progress of degradation of nitrobenzene was monitored by using a UV-visible spectrophotometer. The photodegradation of nitrobenzene could be best realized at a medium pH of 7 and 120 min of irradiation. The reaction rate constant of nitrobenzene degradation catalyzed by TiO2 and Fe3O4/TiO2 solids were found to be 0.0058 min-1 and 0.0092 min-1, respectively. The photocatalyst was recoverable by use of a magnetic bar and reusable.


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