Green synthesis of Ag-MnO nanocomposite from leaves of Hibiscus rosa-sinensis for efficient dye degradation and antifungal applications

This study investigates the green synthesis of a silver-manganese oxide (Ag-MnO) nanocomposite using Hibiscus rosa-sinensis leaf extract, focusing on its photocatalytic and antifungal properties. The synthesis employed a co-precipitation method, and the resulting composite was characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FT-IR). The photocatalytic efficiency was evaluated against three organic dyes: eosin yellow, brilliant green, and malachite green, resulting in degradation rates of 95.65%, 80.70%, and 85.54%, respectively, under sunlight. Further, the Ag-MnO composite exhibited significant antifungal activity, with Candida albicans showing the highest sensitivity (zone of inhibition of 11 mm), followed by Saccharomyces cerevisiae (10 mm) and Aspergillus niger (7 mm). However, it was ineffective against the tested bacterial strains. These findings suggest that the Ag-MnO nanocomposite is a promising multifunctional material for addressing environmental pollution through dye degradation and for potential antifungal applications. The study highlights the advantages of eco-friendly synthesis methods in nanotechnology, paving the way for sustainable solutions in environmental and biomedical fields.