Effect of Annealing Temperature on Structural, Electrical and Optical Properties of TiO2 Nanopowder

TiO2 nanopowder is prepared by simple sol-gel method using starting material as titanium isopropoxide with methanol and annealed at 600°C, 700°C and 800°C for 1 hour in air. X-ray diffraction pattern revealed the presence of both anatase and rutile phase in TiO2 specimens annealed at different temperatures. It is observed that the content of rutile phase and crystallite size increases with increase in annealing temperature. Scanning electron microscopy (SEM) is used to study surface morphology of TiO2 specimens annealed at different temperatures. Using Tauc plot it is observed that energy band gap decreases with increase in annealing temperature. I-V curve of TiO2 specimen shows that current increases with increase in annealing temperature. The preparation method is optimized by changing the concentration of titanium isopropoxide which leads to mixed phase (anatase and rutile) TiO2 nanopowder with a lower energy band gap value which may play an important role in gas sensing applications.