Structural and Optical Characterisation of Double-Doped TiO2 Nanoparticles
Presented by Mr. Olatunbosun NUBI on 10 Jul 2014 from 15:20 to 15:40
Type: Oral Presentation
Track: Track A - Division for Physics of Condensed Matter and Materials
With titanium isopropoxide as the precursor, single and double doped nanosized powders of TiO<sub>2</sub> were synthesised by the sol-gel process. The metal dopants used were Ag, Cu and Fe at doping levels of 5% (molar weight). The post annealing of the samples was done at 300 °C, 600 °C and 900 °C after drying them at 100 °C in air. Structural characterisation of the samples was carried out by X-ray Diffraction (XRD), Raman and scanning Electron Microscopy (SEM) techniques. The results suggests that the co-doped TiO<sub>2</sub> powders are constituted by both the anatase and brookite phases (with the dopant particles incorporated into the TiO<sub>2</sub> matrix) whereas only anatase is observed in the case of pure and singly doped samples (with the dopants residing on the TiO<sub>2</sub> surface). The co-existence of brookite with anatase in the co-doped sample is thought to be responsible for the enhancement of anatase to rutile transformation. Photoluminescence (PL) and UV-visible measurements were done to study the optical properties of the TiO<sub>2</sub> nanoparticles. This revealed the active PL band at around 440 nm. Double doping was found to enhances the narrowing of the band gap, over single doping.