Cerium-doped mesoporous BaTiO3/TiO2 nanocomposites: structural, optical and photocatalytic properties

Nanoscale composite materials based on cerium, barium titanate and titanium dioxide were synthesized by thermal hydrolysis. The obtained individual TiO2, BaTiO3 and as-synthesized Ce/xBaTiO3/TiO2 semiconductive nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive spectrometry, transmission electron microscopy, nitrogen adsorption–desorption, UV–vis diffuse reflectance spectroscopy, and Fourier transform infrared spectroscopy. The structural investigations revealed that all prepared powders were nanocrystalline with an average crystallite size within the range of 5–17 nm. Analysis of nitrogen adsorption–desorption isotherms for the synthesized nanocomposites showed the presence of a hysteresis loop, which is evidence for the mesoporous structure of the powders. The photocatalytic degradation of the model pollutants (Safranine T and Rhodamine B) was carried out under UV irradiation. Ce/xBaTiO3/TiO2 nanocomposites showed higher photocatalytic activity compared to pure TiO2 and BaTiO3 as well as BaTiO3/TiO2. An increase of the amount of BaTiO3 in Ce/xBaTiO3/TiO2 samples by more than 12% reduces the photocatalytic activity of nanocomposites while doping of BaTiO3/TiO2 samples with cerium increases their photoactivity.