RESUMO
A novel magnetic cadmium titanate-copper ferrite (CdTiO3/CuFe2O4) nanocomposite, in which spherical CuFe2O4 nanoparticles were loaded onto the surface of CdTiO3 nanoplates, was successfully synthesized via a sol-gel hydrothermal route at 180 °C. The structure, morphology, magnetic and optical properties of the as-prepared nanocomposite were respectively characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) surface area analysis, UV-visible diffuse reflectance spectroscopy (DRS), vibrating sample magnetometry (VSM) and photoluminescence (PL) spectroscopy. The photocatalytic activity of this novel CdTiO3-based magnetic nanocomposite was investigated for the degradation of organic dye pollutants such as methylene blue (MB), rhodamine B (RhB), and methyl orange (MO) in the presence of H2O2 under visible light irradiation. The results showed that the photocatalyst completely degraded three dyes within 90-100 min. Compared with pure CdTiO3 and CuFe2O4, the heterogeneous CdTiO3/CuFe2O4 nanocomposite exhibited significantly enhanced photocatalytic efficiency. On the basis of the results of the OH trapping and photoluminescence (PL) experiments, the enhanced photocatalytic performance was mainly ascribed to the efficient separation of photo-induced electron-hole pairs and the formation of highly active hydroxyl radicals (OH) species in the CdTiO3/CuFe2O4 photocatalytic oxidation system. The PL measurements of the CdTiO3/CuFe2O4 nanocomposite also indicated an enhanced separation of photo-induced electron-hole pairs. Moreover, the nanocomposite could be easily separated and recycled from contaminant solution using a magnet without a decrease in their photocatalytic activity due to their good magnetic separation performance and excellent chemical stability. Based on these findings, CdTiO3/CuFe2O4 nanocomposite could be a promising visible-light-driven magnetic photocatalyst for converting solar energy to chemical energy for environmental remediation.
