Fabrication of Fe ₃ O ₄ /Ag‐TiO ₂ magnetic nanocomposite for antibacterial applications

Abstract

Water pollution is a major cause of fatality in the less developed parts of the world. One of the major concerns in this regard is due to activities of both Gram‐positive and Gram‐negative bacteria. The Fe3O4/Ag‐TiO2 nanocomposite, stabilized in a matrix of TEOS–APTES, is prepared in this study via a facile chemical procedure as a potential magnetic antibacterial agent for treating pathogen‐polluted aqueous media. The multifunctioning character of this nanocomposite provides photocatalytic effect of TiO2 components combined with Ag nanoparticles (AgNPs), as well as separation capability by magnetic response of Fe3O4 particles. To stabilize the nanocomposite formulation, a matrix of TEOS‐APTES is employed as support to facilitate combination of Ag‐TiO2 nanoparticles with Fe3O4 magnetic cores. When exposed to an external magnetic field, the undesirable release of Ag particles is prevented by the Fe3O4 cores that enable the nanocomposite to be collected from the environment. The magnetic character of the nanocomposite was evidenced by VSM. The morphology of Ag‐TiO2 nanoparticles, the core–shell structure of Ag‐TiO2/Fe3O4 particles, the crystalline structure and hydrodynamic diameter of nanocomposite were investigated by FT‐IR, FE‐SEM, TEM, XRD and DLS analyses. The antibacterial activity of the samples was determined by agar disk diffusion. It was revealed that the Fe3O4/Ag‐TiO2 nanocomposite could produce a larger zone of inhibition than Ag+ ions and Ag‐TiO2, which could be related to the size distribution and synergistic antibacterial effects of Ag and TiO2 components. The designed nanocomposite formulation could be considered as a promising candidate for antibacterial water treatment applications.