Hydrothermal synthesis of titanium dioxide nanoparticles studied employing in situ energy dispersive X-ray diffraction

Abstract

Hydrothermal synthesis of titanium dioxide (TiO₂) nanoparticles has been studied in situ using synchrotron radiation energy dispersive X-ray diffraction (EDXRD). The nanoparticles were produced from an acid (HNO₃) and an alkaline (tetrabutylammonium hydroxide; TBA) peptized gel by hydrothermal treatment at 210 °C and 270 °C. The in situ EDXRD spectra clearly showed that pure TiO₂ rutile phase nanoparticles were crystallized from HNO₃ peptized gel, whereas pure anatase phase nanoparticles were produced from the TBA peptized gel. The EDXRD data shows that the rate of the particle formation increases with an increase in the process temperature for both processes. The powder X-ray diffraction (XRD) and selected area electron diffraction (SAED) data confirms the in situ EDXRD results. The TEM images show that the anatase nanoparticles have relatively homogeneous particle size and morphology distribution whereas the rutile nanoparticles exhibit bimodal size and morphology distribution attributed to Ostwald ripening effect during the hydrothermal treatment.