XRD and SEM studies on annealed nanocrystalline titanium dioxide powder

S.S. Babkair, A.A. Ansari, N.N. Al-Qurashi
King Abdulaziz University, SA

Keywords: nanocrystalline TiO2, phase transition, particle size

Summary:

Anatase phase of nanocrystalline (nC) titanium dioxide in photo-catalysis, photo-splitting of water to produce hydrogen and as electrode material in Dye Sensitized Solar Cells (DSSCs)is mostly used due to its higher band gap. However, recent studies have shown that better performance can be obtained if a small proportion of rutile phase is also present. This study explores the possibility of converting nC-TiO2 powder into any ratio of the anatase and rutile phases by the simple process of annealing. Nanocrystalline titanium dioxide powder was annealed over 150 to 1200C. Phase transition from anatase to rutile was studied by XRD and SEM techniques.It was found that anatase phase transforms to rutile between 600 and 900C. The particle size as determined from Scherrer’s formuls using the XRD peaks show an increase from 30nm for anatase phase to 80nm for the rutile phase as the temperature increases from 600C to 1000C. SEM images confirm this calculation and show the agglomeration of particles at elevated temperatures.