Abstract: TiO₂-based nanotubes (TiO₂NT) were synthesized by hydrothermal treatment under the alkaline conditions using P25 as the raw material. Then copper phthalocyanine (CuPc) was chosen as a sensitizer to prepare CuPc modified TiO₂NT composite material (CuPc/TiO₂NT) by the immersion method. The structure and properties of the samples were characterized, and the photocatalytic activity of pure TiO₂NT and CuPc/TiO₂NT was also evaluated by degradating rhodamine B under the visible light. The results showed that the TiO₂NT had large surface area (362.6 m²/g) and high pore volume (2.039 cm³/g). Even after modified by CuPc, the composite material still kept the high surface area (244.2 m²/g) and pore volume (1.024 cm³/g) for 0.2%CuPc/TiO₂NT. The decrease of recombination of photo-injected electrons is expected to appear attributing to the effective charge separation on the interface of TiO₂NT and CuPc, improving the transfer efficiency of the photo-excited charges under visible light. Furthermore, the catalyst exhibited obvious visible photocatalytic activity after sensitized by CuPc. As the mole percentage of CuPc was 0.2% in the composite, the degradation rate of rhodamine B over 0.2%CuPc/TiO₂NT could reach 59%, increasing by 3.3 times compared with pure TiO₂NT after reaction for 180 min.

Key words: titanium dioxide, nanotube, copper phthalocyanine, sensitizing, visible light, rhodamine B