Microwave-assisted hydrothermal synthesis of Cu-doped titanate nanotubes: Photoluminescence and photocatalysis properties

Abstract

The synthesis of Cu-doped nanotubes was successfully realized using the hydrothermal method assisted by microwave (MWH). The structure found from XRD shows a typical profile of the layered titanate, containing no peak for secondary phases and no copper phase. These titanates have nanotubes morphology, independent of the synthesis time is 2 or 4 hours. From EDS analysis is possible to verify both the copper and sodium presence, indicating the intercalations between Na+ and Cu2- ions on the structure. The photoluminescence analysis indicated that the CuNT-4h sample have more surface defects and lower rate of electron-hole recombination. The presence of these particular types of defects leads to enhanced photocatalytic activity of CuNT-4h sample relative to the other. This study concluded that the Cu-doped nanotubes have higher photocatalytic activity than the TiO2-anatase (synthesis precursor) and their activity depends on the type of defects present in the sample.