| 초록 |
Titania (TiO2) has been studied extensively as a photocatalytic material. High-efficient photocatalytic reactivity of TiO2 can be very promising for electrodes of solar cells, the elimination of pollutants, and the photogeneration of hydrogen from water. However, the wide bandgap energy (~3.0-3.2 eV) of TiO2 limits its photocatalytic reaction to ultraviolet light. Considerable efforts have been taken to extend the reactivity to visible light regime via doping of transition metals or nonmetals such as nitrogen and carbon. However, little information is available on visible-light photocatalysis of 1-D TiO2 nanostructures (nanowires and nanotubes) because synthesis and doping of 1-D TiO2 nanostructures still represents a challenging issue. So far, only ion implantation was introduced to dope nitrogen into TiO2 nanotubes. Ion implantation is a straightforward approach, but it accompanies structural damages to degrade the photocatalytic reactivity significantly. In this study, we performed in-situ doping of strontium (Sr) in TiO2-δ nanobelts during the synthesis by metallorganic chemical vapor deposition (MOCVD). The Sr-doped TiO2-δ nanobelts were self-catalytically grown without the use of any metal catalysts. Moreover, the TiO2-δ anobelts also showed high-efficient visible-light photocatalytic activity, which were evaluated by the decomposition of methylene blue under visible light irradiation. We will further discuss growth mechanism and photocatalytic characteristics of Sr-doped TiO2-δ nanobelts. |
