The study of the change in the optical band-gap of titania nanoparticles supported on silica

Iranian Journal of Physics Research

关键词: titania nanoparticles;    optical band-gap;    silica;    phase transformation;   

DOI  :  

来源: DOAJ

【 摘 要 】

In this letter, titania nanopowder and titania-silica nanocomposite were prepared using sol-gel method. Although the size of nanocrystallites and the mass fraction percent age of rutile phase ( after phase transformation ) were increased by increasing calcination in the two samples , their size in titania-silica nanocomposite was smaller than that in pure titania . Moreover, the calculations of the indirect optical band gap in the two samples show ed that by increasing temperature up to the transition onset point a nd above, the optical band gap had a steady growth and the corresponding wavelength reduced. However , a remarkable red shift in the indirect optical band gap was noticed in both samples around the transition onset point . The red shift was observed more in silica-titania nano composite than in titania nanopowder . In addition, the indirect band gap of silica-titania nano composite was less than that of pure titania in the same temperature conditions.

【 授权许可】

Unknown