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

Abstract

In this article, visible-light-active binary metal doped Mn 0.9 Cu 0.05 Ag 0.05 O 2 (MCAO) nanostructures were synthesized by a one-step co-precipitation method for superior antimicrobial and photocatalytic activities. For comparison, single metal doped Mn 0.95 Cu 0.05 O 2 (MCO), Mn 0.95 Ag 0.05 O 2 (MAO) nanostructures were also synthesized. Accompanied with the co-precipitation growth of the Cu and Ag in the MnO 2 matrix , the binary metal doping not only influenced the crystal structure of MnO 2 , 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 MnO 2 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 Mn 0.9 Cu 0.05 Ag 0.05 O 2 (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.