Synthesis and characterization of dye-doped TiO2-SiO2 core-shell composite microspheres

RhodamineB (RB) dye-doped TiO2-SiO2 core-shell composite microspheres were synthesized by a chemical method from the hydrolysis of the titanium tetrachloride (TiCl4). The morphology and chemical bonding information of composite material was investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). TEM and SEM images illustrate that core-shell composite microspheres are spherical in shape and have a nano-range thin coating of TiO2 on the surface of SiO2. The core-shell composite microspheres calcined at 400 degrees C exhibit sharp XRD peaks of anatase and rutile crystalline phases of TiO2. The unit cell parameters were calculated from different peaks. The FTIR spectrum confirms the existence of stretching modes (Si-O-Si and Ti-O-Ti) in the core-shell composite microspheres. The photocatalytic properties were evaluated by the photo degradation of K2Cr2O7 under ultraviolet-visible irradiation for as-synthesized and at an 850 degrees C calcination temperature of the core-shell composite. (c) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.JNP.6.063511]