Photodegradation of organic dyes and antibacterial activity of Escherichia coli and Staphylococcus aureus by ZnO nanoparticles under UVA radiation

ABSTRACT

Zinc oxide (ZnO) nanoparticles were successfully prepared in solutions with the pH of 10 (S-pH10), 11 (S-pH11) and 12 (S-pH12) by sonochemical method combined with calcination. Phase, morphology and photo-emission were characterised by X-ray powder diffraction, Fourier transform infrared spectroscopy, photoluminescence spectroscopy and field emission scanning electron microscopy. UV-visible analysis indicated the photonic absorption of S-pH10, S-pH11 and S-pH12 with 3.55, 3.51 and 3.54 eV direct band gaps, including the BET analytical specific surface areas of 4.73, 6.90 and 9.14 m²/g, respectively. ZnO was tested for photodegradation of methylene blue rhodamine B and methyl orange dyes under UVA radiation. In this research, S-pH12 has the highest photodegradation efficiency. ZnO also tested for antibacterial activity against Escherichia coli and Staphylococcus aureus growth induced by UVA radiation. S-pH10 has the highest antibacterial activity against S. aureus of 97.4 ± 0.20% but S-pH12 has the highest antibacterial activity against E.coli of 35.7 ± 0.10%.

KEYWORDS:

• Zinc oxide
• sonochemical method
• photocatalysis
• dye degradation
• antibacterial activity

Acknowledgments

We are grateful to Chiang Mai Rajabhat University, Thailand, for providing financial support and facilities to our research, and Center of Excellence in Materials Science and Technology, Chiang Mai University, for financial support under the administration of Materials Science Research Center, Faculty of Science, Chiang Mai University, Thailand.

Disclosure statement

No potential conflict of interest was reported by the authors.