Synthesis, characterization and photocatalytic studies of MCM-41 mesoporous silica core-shells doped with selenium oxide and lanthanum ions

Abstract A synthesis method was developed to produce uniform micro-size spheres of silica coated with MCM-41 mesoporous shell for preparation of SiO2@MCM-41 core-shell. Lanthanum ion and selenium dioxide, were introduced separately and together into this core-shell structure. The SiO2@MCM-41, SiO2@SeO2-MCM-41, La–SiO2@MCM-41 and La–SiO2@SeO2-MCM-41core-shells were prepared. A range of reliable instruments and methods including X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Barrett-Joyner-Halenda (BJH), DLS (dynamic light scattering) and energy-dispersive X-ray spectroscopy (EDS) were employed for characterization of the fabricated core-shells. It was found that presence of La in the core and SeO2 in the mesoporous shell, generate very efficient photocatalytic activity of the materials. The prepared photocatalysts were used for degradation of 2,4-dichlorophenol (DCP) as a model compound. The obtained results showed the photocatalytic efficiency was increased in the order of SiO2@MCM-41 (5%)