Magnetically separable Ag@Fe3O4-GO nanocomposites for SERS detection, removal of organic pollutants and oil from water, and antibacterial applications

Abstract

A facile wet chemical method was employed to synthesize magnetically separable Ag@Fe₃O₄-GO nanocomposites (NCs). The synthesized Ag@Fe₃O₄-GO NCs were characterized by different analytical techniques including X-ray diffraction (XRD), Raman, vibrating sample magnetometer (VSM), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In the synthesized Ag@Fe₃O₄-GO NCs, the role of GO is to adsorb organic dyes from wastewater, superparamagnetic Fe₃O₄ nanoparticles (NPs) assist magnetic separation, and Ag NPs act as a SERS substrate for the detection of organic dyes and as a catalyst to reduce organic pollutants in the presence of a reducing agent (NaBH₄). The catalytic efficiency of the synthesized Ag@Fe₃O₄-GO NCs was evaluated in the reduction of organic pollutants such as methylene blue (MB) in water under mild conditions. These nanocomposites are also efficient for the removal of lubricant oil from water by applying a simple external magnetic field. The composite also displays antibacterial activity towards Gram-positive and Gram-negative bacteria.