ZnO/TiO 2 composites for photocatalytic inactivation of Escherichia coli
| Autor: | R. Sakthivel, Diptipriya Sethi |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Anatase
Materials science Biophysics chemistry.chemical_element 02 engineering and technology Zinc 010501 environmental sciences medicine.disease_cause 01 natural sciences law.invention Absorbance chemistry.chemical_compound law Zinc nitrate medicine Radiology Nuclear Medicine and imaging Calcination Composite material 0105 earth and related environmental sciences Radiation Radiological and Ultrasound Technology 021001 nanoscience & nanotechnology chemistry Photocatalysis 0210 nano-technology Ultraviolet Visible spectrum |
| Zdroj: | Journal of Photochemistry and Photobiology B: Biology. 168:117-123 |
| ISSN: | 1011-1344 |
| DOI: | 10.1016/j.jphotobiol.2017.02.005 |
| Popis: | ZnO/TiO 2 composite was synthesized from zinc nitrate and anatase TiO 2 by using the incipient wet impregnation method followed by calcination at 350 °C for 3 h. These samples were characterized through several characterization techniques. XRD peaks confirms the presence of single anatase phase of titania in the 3 and 6 wt% ZnO/TiO 2 composite, whereas in all other composites both anatase titania and zinc oxide phases were found. UV–visible (diffuse) reflectance spectra show titania and ZnO absorbs in the ultraviolet (UV) region whereas ZnO/TiO 2 absorbs both UV and visible light. The shift in absorbance facilitates ZnO/TiO 2 composites to exhibit photocatalytic activity under UV–visible light irradiation. FE-SEM and TEM analysis reveals that the particle size of ZnO is around 0.2 μm and its size significantly reduced to 25 nm when it is deposited on TiO 2 support. The E . coli inactivation study shows that ZnO/TiO 2 composites exhibit high inactivation compared to ZnO and titania under UV alone and the combination of both UV–visible. With the increasing loading concentration of ZnO, the photocatalytic inactivation potential of ZnO/TiO 2 composites also increases. The E . coli inactivation of ZnO/TiO 2 is explained based on the photocatalytically generated ROS, ZnO dissolution and charge carrier separation due to hybrid structures. |
| Databáze: | OpenAIRE |
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