Fabrication and assessment of CuO and NiO-infused MnO2 nanocomposites: Characterization, methylene blue degradation, and antibacterial efficacy

This study employed the solid combustion method to fabricate CuO and NiO-doped MnO2 nanocomposites (MnNCs). Various spectral techniques confirmed their structural integrity. The Ultraviolet-Visible (UV-Vis) spectrum of the nanocomposites revealed peaks at 466 nm, ascribed to the bandgap and enhance the visible light absorption. The crystalline structure of the nanocomposites was confirmed by X-ray diffraction method. The scanning electron microscopy (SEM) images displayed a dumbbell and spherical shapes, while Transmission Electron Microscope (TEM) showed hexagonal, octahedral, and spherical particles. The elemental composition and oxidation state of MnNCs composites were verified by Energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The EDS analysis results indicate that the prepared composites contain a reasonable amount of Mn, Cu, Ni, and O atoms. Additionally, based on the XPS results, the estimated percentages of Mn, Cu, Ni, and O are 49.48%, 8.79%, 11.84%, and 22.91%, respectively. The MnNCs-2 composites exhibit superior photocatalytic activity compared to MnO2 and MnNCs-1. Within 100 min, the MnNCs-2 nanocomposites demonstrate an 89.05% efficiency in degrading MB dye. The synthesized MnNCs nanocomposites are found to be extremely toxic against Gram-positive bacteria, Staphylococcus aureus (S. aureus), Streptococcus pyogenes (S. pyogenes), and Gram-negative bacteria, Escherichia coli (E. coli), and Klebsiella pneumoniae (K. pneumoniae). This study underscores the potential of MnNCs nanocomposites as versatile photocatalysts and antibacterial agents