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Effects of Calcination Temperature on Properties of 30%Gd2Ti2O7/SiO2 for Photocatalytic Degradation of Ofloxacin - Gd2Ti2O7 Supported on SiO2

[ Vol. 14 , Issue. 6 ]

Author(s):

Wenjie Zhang*, Jiao Yang and Chuanguo Li   Pages 456 - 462 ( 7 )

Abstract:


Background: Photocatalytic materials can be prepared in the supported form in wastewater treating devices. The quartz sphere can be regarded as a suitable support for photocatalytic material since it is transparent to UV irradiation.

Methods: Gd2Ti2O7 was supported on quartz spheres by a sol-gel method in this work to study the effects of calcination temperature on the properties of the composite 30%Gd2Ti2O7/SiO2. The materials were characterized using scanning electron microscopy, transmission electron microscopy, Xray powder diffraction, FT-IR/Far IR spectroscopy, UV-Vis spectrometry, fluorescence spectrophotometry, and surface area and pore analyses.

Results: Crystallization of pyrochlore structured Gd2Ti2O7 starts at 800oC. The FT-IR absorptions of Gd2Ti2O7 occur in the spectra of the samples calcined over 800oC. Band gap energy of the 30%Gd2Ti2O7/SiO2 decreases from 3.66 eV at 600oC to 3.43 eV at 1000oC. The sample calcined at 800oC has the maximum photocatalytic degradation efficiency of 59.5% after 30 min of irradiation.

Conclusion: The increase of calcination temperature leads to a slight cell expansion of pyrochlore structured Gd2Ti2O7 crystals that forms above 800oC. The increase in calcination temperature leads to constant reducing band gap energy of 30%Gd2Ti2O7/SiO2. The maximum amount of hydroxyl radical is produced in the solution containing 30%Gd2Ti2O7/SiO2 calcined at 800oC, accompanied with the maximum ofloxacin degradation efficiency on that sample.

Keywords:

Gd2Ti2O7, Photocatalytic, SiO2, support, ofloxacin, degradation.

Affiliation:

School of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang 110159, School of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang 110159, School of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang 110159

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