| 초록 |
Photocatalytic materials have been received dramatic increase in their demand of research, development and applications such as purification of air / water, antibacterial and self-cleaning etc. In this present talk, environmentally friendly green processes, including "solvothermal process" and "mechanochemical doping process", for the synthesis of anion or cation doped visible-light-active photocatalyst materials will be introduced. Anatase, brookite and rutile type nitrogen or carbon doped titania nanocrystals (TiO2-xAy, A=N,C) were successfully prepared as single phase by the solvothermal process at such low temperature as 190oC. High visible-light-active anion doped photocatalyst powders could be prepared by mechanochemical doping process at around room temperature also. Not only nitrogen doped titania, but also other photocatalyst materials doped with various kinds of anions such as TiO2-xNy, TiO2-xCy, TiO2-xSy, TiO2-xNyCz, SrTiO3-xNy, SrTiO3-xFy, SrTiO3-xNyFz, LaxSr1-xTiO3-yNz,and ZnO1-xNy were successfully prepared. Compare with conventional preparation process, these materials prepared by low-temperature green chemical processes show excellent photocatalytic activities because of their fine particles, high specific surface area, high crystallinity and high anion doping amount. Some composite type photocatalysts such as TiO2-xAy / ZnO nanorod, TiO2-xAy / CaAl2O4:(Eu, Nd), SrTi1-xCryO3/CaAl2O4:(Eu,Nd) were also synthesized. These photocatalysts showed excellent visible-light absorption and photocatalytic activity for nitrogen monoxide destruction and acetaldehyde degradation under irradiation of both UV-light and visible-light irradiation. Some recent research topics such as “non-stoichiometric photocatalyst”, “LED light induced photocatalytic system”, “full-time active luminescent photocatalytic system” and “IR light induced photocatalytic system” will be introduced also. |
