Green Synthesis of Zinc Oxide Nanoparticles from Allium cepa Skin: Photocatalytic Degradation and Antibacterial Properties

Abstract

Abstract The present study uses a bio-waste i.e., skin of Allium cepa, for green synthesis of zinc oxide nanoparticles. The nanoparticles A.Cepa-ZnONP were tested for their photo catalytic degradation efficacy towards harmful dyes. Additionally, the anti-bacterial properties of A.Cepa-ZnONP were evaluated against four organisms, namely Escherichia coli (EC), Pseudomonas aeruginosa (PA), Bacillus cereus (BC), and Staphylococcus aureus (SA). The synthesized A.Cepa-ZnONP was characterized with scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) methods. The A.Cepa-ZnONP demonstrated efficient degradation of Crystal Violet (CV), Rhodamine B (RB), and Methylene blue (MB) dyes, achieving maximum degradation percentages of 99.21%, 95.63%, and 92.34%, respectively, while operating under optimal process conditions. The rate constant values for CV, RB, and MB dyes at a temperature of 328K were determined to be 0.1063, 0.0758, and 0.0447 min-1, respectively. The activation energy values for CV, RB, and MB dyes were determined to be 12.28, 18.437, and 50.623 kJ/mol, respectively. The successful regeneration of photo catalytic material A.Cepa-ZnONP is a crucial milestone in guaranteeing their long-term effectiveness and practical usability.