Morphology dependence of photocatalytic activity of zinc oxide nanostructures on water disinfection

Authors

• Sekineh Khodadad ¹
• Davoud Dorranian * ²
• Peyman Azimi Anaraki ¹
• Reza Mirnejad ³
• Tania Davari Mahabadi ⁴

1. Physics Department, Takestan Branch, Islamic Azad University, Takestan, Iran
2. Laser Lab., Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran, Iran
3. Molecular Biology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
4. Department of Physics and Biophysics, Faculty of Health, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran

Abstract

Dependence of the photocatalytic activities of zinc oxide (ZnO) nanostructures on their morphology was investigated experimentally. Spherical and nanorod morphologies of ZnO  nanostructures were synthesized by laser ablation and hydrothermal methods respectively, and were characterized by FESEM images and UV-Vis-NIR spectra. The bandgap energy of ZnO nanospheres was 3.75 eV, while for the ZnO nanorods the bandgap energy was 3.07 eV. Their photocatalytic activities to decontaminate water polluted Escherichia coli (E.  coli) bacteria were examined in the dark condition and under the UV irradiation. Furthermore, effects of other parameters including size, illumination power, and time were observed. The ZnO nanorods exhibited higher inactivation efficiency in comparison with spherical nanostructures. Results show that in the decontamination process, after  distraction of the membrane of E. coli, the intercellular dissolved matters including proteins, and sugars flowed out gradually leaded to complete decay of the cell. Results confirm that the area and bandgap energy of nanostructures have determinative role in their photocatalytic activities.

Keywords

• Photocatalytic Activity
• ZnO nanoparticle
• Escherichia coli
• Nanorod