Synthesis and characterization of super paramagnetic composite photocatalyst-Titania/silica/nickel ferrite

Composite photocatalysts with TiO(2) porous shell and magnetic core were synthesized by using NiFe(2)O(4) as a magnetic core, SiO(2) as an intermediate layer and polyethylene glycol with molecular weight of 1000 (PEG 1000) as a template direction agent. The samples were characterized with N(2) adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), vibrating sample magnetometry (VSM) and ultraviolet-visible (UV-vis) spectroscopy. The results showed that the obtained composites are spherical particles about 50 nm in diameter. The mesoporous TiO(2) with magnetic core calcined at 350 degrees C, 450 degrees C, and 550 degrees C was found to have, respectively, different specific surface areas (94, 86, and 68 m(2)/g) and average pore sizes (1.4, 2.2, and 2.8 nm). The photocatalytic activity was investigated for degradation of nitrobenzene under UV irradiation. Nitrobenzene was decomposed in 300 min under irradiation of an 8W UV lamp with a peak wavelength of 253.7 nm. The composite nanoparticles exhibited high photocatalytic efficiency and super paramagnetic nature for cleaning polluted water by magnetic separation. (C) 2011 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.