The Feynman lectures on Physics

Feynman is a great physicist. His lectures are very useful for anyone who love physics.You can consult here:

http://www.feynmanlectures.caltech.edu/

Titanium dioxide (TiO2)

Titanium dioxide (TiO₂) has plenty of applications such as white pigment in pain, paper, confectionery etc. Morever, it has been widely as catalyst to air and water treatment. This material is a semiconductor, it absorbs UV light. Therefore, TiO₂ is used as UV blocker in sunscreen. Recently, it is used as photoactive material for solar panel. (Fujishima 2008). Moreover, in biomaterial application, a nanolayer of TiO₂ presents on Ti-based implants.  

The most populous polymorph of TiO₂ is anatase and rutile, which is different from each other through the organization of Ti and O atoms inside the crystal. (Diebold 2003)  

The properties of TiO₂, thus its usage depends on the morphology of particles. Therefore, new methods to control its size, shape at synthesis step are essential. Litterature data indicated that scientists are able to manipulate the exposed facets of TiO₂ nanoparticles. Luc Brohan (IMN-Nantes) for example, can synthesize 2D TiO₂. (Vincent, Ph.D. disseration 2013, Université de Nantes). Other group in China was able to synthesize TiO₂ anatase NPs which are prodominant by (001) facets. (Nature 2008)