Influence of Calcination Temperature on Crystal Structure of Pt-TiO2 Nanofibers.

Platinum (Pt) doped TiO2 nanofibers were prepared by a sol-gel derived electrospinning and subsequent calcination for 3 h at temperatures from 500 degrees C to 700 degrees C in air. The influence of calcination temperature on crystal structure of the Pt-TiO2 nanofibers was investigated by using an X-ray diffractometer (XRD) and a transmission electron microscope (TEM). The fibers possessed both anatase and rutile phases of TiO2 as a function of the calcination temperature. At 500 degrees C, only anatase phase was observed. However, the rutile phase started to grow with increasing the temperature. At 700 degrees C, 47% of rutile phase with a crystallite size of 31 nm was detected. The continuous and smooth Pt-TiO2 fibers with a diameter of 38 nm were changed to the particulate morphology (at 700 degrees C) with increasing the temperature. This result is particularly important because the calcination temperature is attributed to the fiber morphology and the crystal structure.