Highly dispersibleFe3O4-Ag@OPO(OH)2nanocomposites as a novel eco-friendly magnetic retrievable catalyst for the reduction ofp-nitrophenol

In this study, Fe3O4-Ag@OPO(OH)(2)nanocomposites (NCs) were synthesized usingCamellia sinensisleaf extract. This herbal extract was utilized to reduce silver(I) ions to silver nanoparticles (NPs) on the surface of magnetite. The solution color changes from bright to dark, along with the new absorption band at lambda(max)410 nm confirms the deposition of nanosilver on the magnetite surface. The X-ray powder diffraction (XRD) analysis was used to characterize the diffraction patterns of silver and magnetite phases and to calculate the average size of the crystallites being 21 nm. The fourier transform infrared (FT-IR) spectra of green prepared of Fe3O4-Ag@OPO(OH)(2)NCs illustrated the functional group peaks of flavonoids and other phenolic compounds. The energy dispersive X-ray (EDS) spectra of Fe3O4-Ag@OPO(OH)(2)NCs proved the presence of localized elements, which are incorporated into prepared NCs containing Ag, Fe, O, and P. The vibrating-sample magnetometer (VSM) analysis indicated that the magnetic nature of Fe3O4-Ag@OPO(OH)(2)NCs is less than Fe(3)O(4)NPs, which is attributed to nonmagnetic nature of Ag NPs and covering the magnetite surface by layers of silver and phosphate. The eco-friendly synthesized Fe3O4-Ag@OPO(OH)(2)NCs exhibited high catalytic activity toward reducingp-nitrophenol.