Green synthesis of zinc oxide nanoparticles from Allium cepaskin: photo catalytic degradation and antibacterial properties

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 toward 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 328 K 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. This work also emphasizes the possible uses of A. cepa-ZnONP in environmental remediation. This demonstrates the wide range of applications and importance of this substance in addressing current problems.