Novel substituted porphyrins: synthesis, characterization and photocatalytic activity of their TiO2-based composites

Four novel porphyrins and their corresponding zinc complexes were synthesized and characterized spectroscopically. Effects of the spacer length of peripheral substituents of porphyrin are investigated in TiO 2 -porphyrins hybrid systems by photodegradation of methyl orange in aqueous solution under visible light. The photocatalysts were characterized by means of scanning X-ray diffraction, UV–Vis spectra, X-ray photoelectron spectroscopy and FT-IR spectra. The results indicated that zinc porphyrins were successfully loaded and interacted with the surface of TiO 2 microsphere, which is crucial to enhance the activity of the catalytic composite under visible light. All the new photocatalysts showed much enhanced photoactivity than bare TiO 2 . Especially, the photocatalytic activity of 5,10,15-triphenyl-20-[4-(4-naphthoxy)butoxy] phenyl zinc porphyrin-TiO 2 is higher than others.