Preparation of highly photocatalytically active rutile titania nanorods decorated with anatase nanoparticles produced by a titanyl-oxalato complex solution

Rutile phase titania (TiO2) nanorods and anatase nanoparticles were successfully synthesized from a titanyl-oxalato complex solution prepared using titanium (IV) sulfate and oxalic acid by a hydrothermal process. The impact of various hydrothermal conditions on the formation, morphology, phase, and grain size of the TiO2 nanocrystals was investigated using fourier transformation infrared spectroscopy, X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, and nitrogen adsorption. The photocatalytic activities have been evaluated for the photo-decomposition of phenol under ultraviolet visible illumination. The results revealed that the TiO2 rutile nanorods decorated with anatase nanoparticles (with ~22% anatase) prepared at 160 °C for 72 h exhibit a higher photocatalytic activity than those pure anatase nanoparticles. This behavior was closely related to the better charge carrier separation in the cases of rutile-anatase mixtures. In addition, the possible growth mechanism and phase development of the rutile nanorods and anatase nanoparticles were illustrated.