Fabrication of cellulose capped MnxOy-Ag nanocomposite and investigation of its oxidative and antibacterial efficacy in water environment

Abstract

Computationally newly designed a multifunctional nanoscale Mn3O4-Ag matrix through the Density Functional Theory (DFT) was successfully fabricated by using a simple chemical deposition synthetic route. The matrix thus obtained was characterized by means of EDX, XRD, FT-IR, and SEM. The results showed that the obtained Mn3O4-Ag were spherical, and uniformly dispersed. The average crystallite size was calculated from the XRD data to be approximately 17 nm. The electronic structure and optical properties predicted by Generalised Gradient Approximation (GGA) with Perdew Burke Ernzerhof (PBE) are completely consistent with the experimental results. From the computational study, it found that the Mn3O4-Ag matrix shows excellent optical properties than their single Mn3O4 solid. The calculated band gap of 3.520 eV and 2.431 eV for the Mn3O4, and Mn3O4-Ag solid matrixes respectively through the GGA with PBE which was actually equal to the experimental band gap. The efficiency of the Mn3O4-Ag nanocomposites (NCs) on the decolorization of methylene blue (MB) dye has been studied in presence of HCl. Effect of MB concentration, amount of NCs required, influence of initial dye solution pH, and function of time on MB decolorization were also investigated by employing UV-Visible spectroscopy, It was found from these investigations that Mn3O4-Ag NCs can efficiently and rapidly decolorize MB in adequately acidic media. The Mn3O4-Ag NCs was also successfully employed to deco!orize an industrial dye effluent. UV-Visible spectra of the solutions were taken in all cases to measure the extent of decolorization. Aside from oxidative capacity, Mn3O4-Ag NCs exhibit moderate antibacterial activity against the pathogens Bacillus cereus, Bacillus megaterium, Bacillus subtilis, Staphylococcus aureus, Salmonella typhi, Escherichia coli, Shigella dysenteriae, and Pseudomonas aeruginosa which causes foodborne illness, brain abscess, endocarditis and skin and soft tissue infections fever, diarrhea, dysentery and pneumonia respectively. The antibacterial activity of the Mn3O4-Ag NCs is comparatively higher than that of Ag and Mn3O4 nanoparticles and nearly half that of the standard ciprofloxacin antibiotic that is effectively used for the prevention of the above mentioned diseases worldwide.