Synthesis of CuPc/TiO2 Nanotube Composite Materials with Large Surface Area and Their Photocatalytic Activity under Visible Light

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 (CuPciTiO(2)NT) 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 m(2)/g) and high pore volume (2.039 cm(3)/g). Even after modified by CuPc, the composite material still kept the high surface area (244.2 m(2)/g) and pore volume (1.024 cm(3)/g) for 0.2%CuPc/TiO2NT. The recombination of photo-injected electrons decreases based on 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.