Green synthesis of mediated Morus alba copper oxide nanoparticles and their photocatalytic dye degradation, antioxidant and antimicrobial studies
摘要
Herein, we report the green synthesis of Copper oxide nanoparticles (CuO NPs) made from the aqueous extract of Morus alba leaves; an agricultural waste, rarely used; in order to mitigate persistent pollutants and microbial threats. The biomolecules found in the plant extract acted as the reducing and stabilizing agents. The identification of the generated CuO NPs was performed using UV–Vis spectroscopy, FTIR, XRD, SEM, and zeta potential analysis, revealing distinct structural, morphological, and surface features. The size of CuO NPs ranges between 10 and 35 nm, they displayed an absorption peak at 269 nm, a band gap energy of 2.2 eV, and a zeta potential of − 29.4 mV, indicating high stability and photocatalytic capacity. They demonstrated exceptional photocatalytic efficiency by degrading 97% of Toluidine Blue (TB) dye and 60 min of sunlight irradiation exposure, corresponding to a rate constant of 0.0526 min−1. The kinetics of the photodegradation reaction followed the pseudo first order kinetic model. Antioxidant tests revealed a concentration dependent activity, with 73.5% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging at 75 µg/mL and an IC50 value of 24.44 ± 0.73 µg/mL, as well as a reducing power of 0.5 absorbance units at 1000 µg/mL. Furthermore, the total antioxidant capacity was equivalent to 0.07 µg ascorbic acid per milligram. Antimicrobial evaluations showed a good inhibition zone against Staphylococcus aureus (15 ± 0.5 mm), Escherichia coli (13 ± 03 mm), and Candida albicans (23 ± 0.6 mm) at 80 µg/mL, demonstrating broad-spectrum activity. These results highlight the potential of Morus alba-derived CuO NPs as a potent sustainable, multipurpose agent for environmental remediation and biomedical applications. The present work is cost effective, eco-friendly, benign and can be used for large-scale fabrication of CuO NPs.