Photoinduced interfacial charge transfer and photocatalytic behavior of TiO2 nanotubes sensitized by copper (II) meso-tetra (4-carboxyphenyl) porphyrin

In this paper, a neoteric copper (II) meso-tetra (4-carboxyphenyl) porphine (CuTCPP) was combined with TiO2 nanotubes to prepare photocatalyst under visible light through the methods of the improved hydrothermal and heating reflux process. The material was characterized by transmission electron microscopy (TEM), Energy Dispersive Spectrometer (EDS), X-ray diffraction (XRD), diffuse reflectance UV–Vis spectra (DRS), X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy (PL), and electron paramagnetic resonance (EPR). The photocatalytic effects of TiO2 nanotubes sensitized with this copper (II) porphyrin were surveyed by the photodegradation of methylene blue (MB) in aqueous solution under visible light irradiation. The results showed that the TiO2 nanotubes sensitized by CuTCPP could enlarge the wavelength response range, transfer the excited electrons and separate the photo-generated electron–hole pairs more effectively. The photocatalytic activity was improved under visible light irradiation in the end.