Abstract
Photocatalytic degradation of pollutants is considered to be an effective green method to remove organic dyes from contaminated water. This research work presents the synthesis of a magnetically recoverable ruthenium-magnetite (Ru/Fe3O4) nanocomposite for the photocatalytic degradation of methylene blue (MB) in an aqueous solution under UV and sunlight radiation. The magnetic Ru/Fe3O4 nanocomposite is synthesized in a single step using the chemical co-precipitation method. The synthesized nanocomposite sample is characterized by various techniques, including, XRD, FT-IR, SEM, TEM, TEM-EDX, XPS and VSM whereas the photocatalytic degradation of MB is analyzed by the UV-Vis spectrophotometer. The formation of ruthenium nanoparticles in magnetic Fe3O4 has been confirmed by TEM, TEM-EDX and XPS studies. The catalytic activity of the synthesized Ru/Fe3O4 nanocomposite is evaluated by photodegradation of the MB dye aqueous solution under UV and sunlight radiation. The influences of various operation parameters on photocatalytic degradation such as pH, dye initial concentration and catalyst dosage are examined. The results revealed a complete photocatalytic degradation of MB in the aqueous solution occurred by exposure to both UV and sunlight radiation. Furthermore, the photocatalytic degradation of MB under UV light is faster than sunlight. The photocatalytic degradation reaction of MB is found to be consistent with the pseudo-first-order kinetics. The strong ferromagnetic nature of Fe3O4 enables the nanocomposite to be separated from the solution for recycling and has a photocatalytic efficiency of greater than 90% for up to five cycles. The synthesized Ru/Fe3O4 photocatalyst efficiently degrades MB dye, so it can be used as a potential catalyst for the removal of MB in aqueous solutions.