Synthesis of visible light active surfaces
Titanium dioxide (TiO2) films and coatings have been shown to be very effective in photo-oxidation applications due to their photocatalytic properties. However, due to the large band gap energy of TiO2, conventional coatings can only be activated under ultraviolet light, which represents only a small fraction (<5%) of incident solar light.
The aim of this project is to prepare a nitrogen-doped titanium dioxide coating using the sol-gel technique. Surface and bulk modification by anions changes the band gap of the titanium dioxide and enables it to utilise more of the visible spectrum, thereby increasing its efficiency under visible light. The doped titanium dioxide will be examined with respect to crystal structure, composition, flat band potential, isoelectric point, and photocatalytic activity.
Major achievements and highlights
The TiO2 absorption spectrum was extended into the visible range by doping with urea-sourced nitrogen. The visible light photocatalyst showed good activity in the oxidation of iodide to iodine under both UV and indoor lighting conditions when compared to a commercial photocatalyst (Degussa P25).
Future plans and directions
Future work will focus on exploring the electronic structure of nitrogen-modified TiO2 photocatalysts through photocurrent and surface photovoltage studies.
