Ru(ii)-Metal complex immobilized mesoporous SBA-15 hybrid for visible light induced photooxidation of chlorophenolic compounds in aqueous medium.

The work focuses on room-temperature photocatalytic degradation of phenolic compounds by Ru(ii)-complex immobilized mesoporous silica SBA-15 under visible light in an aqueous medium. The immobilization of [Ru(bpy)3]Cl2 complex on an SBA-15 surface is carried out, and the as-synthesized hybrid is characterized by X-ray Diffraction (XRD), Fourier Transformation IR Spectroscopy (FTIR), Diffuse Reflectance Spectroscopy (DRS), Brunauer-Emmett-Teller analysis (BET), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX) and X-ray Photoelectron Spectroscopy (XPS). Kinetic studies of photodegradation reactions are followed by High Performance Liquid Chromatography (HPLC). Control studies are performed to elucidate the nature of the photodegradation process. The maximum degradation of DCP reached 95% for 10 ppm concentration of the contaminants with an optimum amount of catalyst being 1 g L-1 in 150 min of light irradiation. The long-lived intermediates are identified by HPLC, and the final products are identified by GC-MS. From a series of experiments, the mechanistic steps of the photodegradation process are identified.