Influence of polarity of the peripheral substituents of porphyrin molecules on the photocatalytic activity of Cu(ii) porphyrin modified TiO2 composites

Abstract

Two novel porphyrins, 5,10,15-tri-phenyl-20-[4-(2-(4-formoxyl) phenoxy)ethoxy]phenyl porphyrin and 5,10,15-tri-phenyl-20-[4-(2-(4-hydroxyimino) phenoxy)ethoxy]phenyl porphyrin, and their corresponding copper(II) complexes were synthesized and spectroscopically characterized. The Cu(II) porphyrin–TiO₂ composites were also prepared and characterized. The photoactivity of the composites was investigated by carrying out the degradation of 4-nitrophenol (4-NP) in aqueous solution under UV-visible light. It was found that the photoactivity of Cu(II) porphyrin–TiO₂ composites was evidently influenced by the interaction between porphyrin molecules and hydroxyls anchored on the TiO₂. Furthermore, the photoactivity of Cu(II) porphyrin–TiO₂ composites was also affected by dispersion of composites in 4-NP solution.