Synthesis and photocatalytic performance of urchin-like TiO2/ZnO microspheres
CHENG Jun1,, LI Yuan1, WANG Guoshu1, ZHANG Huigui1, GUO Zhiqiang2,,, ZHOU Ru3, XU Jinzhang3 1.School of Electronic Science & Applied Physics, Hefei University of Technology, Hefei 230009, China 2.School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China 3.School of Electrical Engineering and Automation, Hefei University of Technology, Hefei 230009, China
Abstract:In order to improve the performance of TiO2 photocatalysts, urchin-like TiO2/ZnO microspheres were prepared by K2TiO(C2O4)2 and Zn(NO3)2·6H2O via a facile two-step hydrothermal method. The crystal structure, element composition, surface morphology and specific surface area of as-prepared microspheres were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and gas adsorption apparatus. Furthermore, the photocatalytic property of prepared microspheres was investigated by degrading the tetracycline hydrochloride (TCH) solution under the irradiation of 300 W Xenon lamp. Moreover, the effect of ZnO content in the composite microspheres on the photocatalytic performance was investigated, and the active species were detected and identified by different kinds of radical scavengers. The results showed that the prepared urchin-like microspheres had large specific surface area and suitable mesoporous distribution, and good adsorption capacity toward TCH, which laid a foundation for their high photocatalytic degradation performance on TCH degradation. The TiO2/ZnO microspheres (TZ60) synthesized by 60 mg Zn(NO3)2·6H2O and 0.2 g TiO2 microspheres had the best photocatalytic activity. After 4 hours illumination, the final removal rate and mineralization rate of TCH with initial concentration of 100 mg·L?1 could reach 99.3% and 41.4%, respectively. TCH was photodegraded into small molecule organics or mineralized into CO2, H2O and so on, and h+ and $ \cdot {\rm{O}}_2^ - $ were the main active species during photodegradation process. Key words:hydrothermal method/ urchin-like microsphere/ TiO2/ZnO composite/ tetracycline hydrochloride/ photocatalytic degradation.
图1TiO2微球和一系列TiO2/ZnO复合材料的XRD图 Figure1.XRD patterns of TiO2 microspheres and a series of TiO2/ZnO composites
图5TiO2和TZ60微球的氮气吸脱附等温线和孔径分布 Figure5.Nitrogen adsorption-desorption isotherms and the corresponding pore size distributions of the TiO2 and TZ60 microspheres
图7TiO2和TiO2/ZnO微球对TCH光降解的一级反应动力学拟合图 Figure7.Fitting diagram of the first-order reaction kinetics of the photodegradation of TCH by the TiO2 and TiO2/ZnO microspheres
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1.School of Electronic Science & Applied Physics, Hefei University of Technology, Hefei 230009, China 2.School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China 3.School of Electrical Engineering and Automation, Hefei University of Technology, Hefei 230009, China Received Date: 2021-02-08 Accepted Date: 2021-04-27 Available Online: 2021-07-23 Keywords:hydrothermal method/ urchin-like microsphere/ TiO2/ZnO composite/ tetracycline hydrochloride/ photocatalytic degradation Abstract:In order to improve the performance of TiO2 photocatalysts, urchin-like TiO2/ZnO microspheres were prepared by K2TiO(C2O4)2 and Zn(NO3)2·6H2O via a facile two-step hydrothermal method. The crystal structure, element composition, surface morphology and specific surface area of as-prepared microspheres were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and gas adsorption apparatus. Furthermore, the photocatalytic property of prepared microspheres was investigated by degrading the tetracycline hydrochloride (TCH) solution under the irradiation of 300 W Xenon lamp. Moreover, the effect of ZnO content in the composite microspheres on the photocatalytic performance was investigated, and the active species were detected and identified by different kinds of radical scavengers. The results showed that the prepared urchin-like microspheres had large specific surface area and suitable mesoporous distribution, and good adsorption capacity toward TCH, which laid a foundation for their high photocatalytic degradation performance on TCH degradation. The TiO2/ZnO microspheres (TZ60) synthesized by 60 mg Zn(NO3)2·6H2O and 0.2 g TiO2 microspheres had the best photocatalytic activity. After 4 hours illumination, the final removal rate and mineralization rate of TCH with initial concentration of 100 mg·L?1 could reach 99.3% and 41.4%, respectively. TCH was photodegraded into small molecule organics or mineralized into CO2, H2O and so on, and h+ and $ \cdot {\rm{O}}_2^ - $ were the main active species during photodegradation process.