Copper and silver substituted MnO2 nanostructures with superior photocatalytic and antimicrobial activity

Abstract In this article, visible-light-active binary metal doped Mn0.9Cu0.05Ag0.05O2 (MCAO) nanostructures were synthesized by a one-step co-precipitation method for superior antimicrobial and photocatalytic activities. For comparison, single metal doped Mn0.95Cu0.05O2 (MCO), Mn0.95Ag0.05O2 (MAO) nanostructures were also synthesized. Accompanied with the co-precipitation growth of the Cu and Ag in the MnO2 matrix, the binary metal doping not only influenced the crystal structure of MnO2, but also resulted in a remarkable improvement of the visible light activity and the prolonged separation of photoinduced carriers. The phase, morphology, and the chemical composition of the singly and binary doped MnO2 nanostructures were probed by reliable analytical methods, like PXRD (powder X-ray diffraction), FE-SEM (field emission scanning electron microscopy), and EDX (energy dispersive X-ray spectroscopy), respectively. Based on the assessment of the antibacterial and photocatalytic performance, it was observed that the Mn0.9Cu0.05Ag0.05O2 (MCAO) obtained a substantial improvement for different bacterial strains (S. aureus (G+), K. pneumonie (G-), and P. vulgaris (G-)) disinfection and methylene blue (MB) degradation under solar irradiation, which was ascribed to delayed charge recombination as well as effective generation of reactive species ( h + , O ‾ 2 · , and H O • ). These results revealed that the binary metal doping in a metal oxide matrix could provide a novel strategy for development of multifunctional nanomaterials.