Synthesis of a novel catalyst based on Ag nanoparticles on mesoporous silica for reduction nitro aromatic compounds in aqueous solution

In the last decade, silver (Ag) nanoparticles have attracted extensive attention due to their catalytic properties for a variety of organic reactions [1]. Several investigations have been reported on preparation and catalytic activity of Ag NPs. However, metal-nanoparticle catalysts always encounter limitations, because of the problems associated with their separation from the products by traditional methods [2]. Nitroaromatic compounds are generally prepared via nitration of simple aromatic compounds and are extensively being used in various industries such as plastics, dyeing, agriculture, etc. As a result, nitroaromatic compounds are usually present in industrial effluents and agricultural waste water [3]. Hereby we report amine functionalized mesoporous magnetite nanoparticles as a robust support for uniform dispersion of Ag nanoparticles. Silver nanoparticles were formed on the surface of mesoporous silica via coordination of Ag+, followed by chemical reduction. The resulting Fe3O4@SiO2@KIT-Ag nanomaterial was characterized by powder x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM). Also, we use it as an effective catalyst in the reduction of a variety of nitroaromatic compounds.