Title:Effects of Calcination Temperature on Properties of 30%Gd2Ti2O7/SiO2 for Photocatalytic Degradation of Ofloxacin - Gd2Ti2O7 Supported on SiO2
VOLUME: 14 ISSUE: 6
Author(s):Wenjie Zhang*, Jiao Yang and Chuanguo Li
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
Keywords:Gd2Ti2O7, Photocatalytic, SiO2, support, ofloxacin, degradation.
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.
