Efficient visible photodegradation of 4-nitrophenol in the presence of H2O2 by using a new copper(II) porphyrin-TiO2 photocatalyst

A new imidazolyl-linked pophyrin, 5-[4-(2-imidazolyl)ethoxyl]phenyl-10,15,20-triphenylporphyrin and its copper(II) porphyrin were synthesized and characterized spectroscopically. The CuPp-TiO2 photocatalyst was also prepared and characterized by means of high-resolution transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis spectra and FT-IR spectra. The photocatalytic activity was investigated by photodegradation of 4-nitrophenol (4-NP) in aqueous solution with a small amount of H2O2 under visible light irradiation (lambda > 400 nm). The results indicated that H2O2 can enhance greatly the visible photocatalytic activity of CuPp-TiO2 photocatalyst. Additionally, a possible mechanism of the photocatalytic degradation was proposed. (c) 2012 Elsevier B.V. All rights reserved.