Magnetic multifunctional particles with molybdenum dichalcogenide nanostructures for efficient removal of organic dyes and their detection using SERS

Abstract

The development of novel multifunctional composites for environmental applications has been in focus due to increased pollution and health concerns. Organic dyes, in particular, pose a serious threat to aquatic life and human health as they can enter into the ecosystem from the industrial wastes that are dumped into water bodies such as lakes and rivers. Apart from the conventional photocatalytic materials, two-dimensional materials such as MoS₂ have been explored to remove these pollutants. In this work, a multifunctional magnetic-plasmonic composite with Fe₃O₄ core covered with graphene oxide and Ag nanoparticles followed by MoS₂ layer (Fe₃O₄@GO@Ag@MoS₂) is synthesized using chemical methods. The composite particles were characterized using different analytical methods such as powder X-ray diffraction, Raman spectroscopy, vibrating sample magnetometer, and UV–Vis spectrophotometry. The prepared samples were utilized for the adsorption and removal of organic dyes such as rhodamine 6G, malachite green, methylene blue, and methyl orange. The adsorption kinetics were studied using a pseudo-first-order fitting. Furthermore, we used surface-enhanced Raman scattering to monitor the organic dye removal from the solution. Our experimental results showed that the composite particle system showed enhanced adsorption in comparison to simpler systems such as Fe₃O₄@MoS₂. These multifunctional particles also showed good photocatalytic capability for the degradation of the dyes. Excellent adsorption properties, recyclability, and photocatalytic properties make the multifunctional composite promising candidates for environmental applications.