Immobilization of a Series of Homo/Heterobinuclear Metal (II) Phthalocyanine Hexasulphonates on Nanocrystalline TiO<sub>2</sub> Thin Films and their Application in the Degradation of Methylene Blue

Abstract

A series of binuclear metal (II) phthalocyanine hexasulphonates, (M-M)Pc, including (Co-Co)Pc, (Co-Zn)Pc, (Co-Mn)Pc, (Zn-Zn)Pc, (Zn-Mn)Pc and (Mn-Mn)Pc were synthesized and immobilized on nanocrystalline TiO2 thin films. The nanocrystalline TiO2 thin film was characterized by SEM, XRD and profilometer. The catalytic activity of various (M-M)Pc/nanocrystalline TiO2 thin films was evaluated by the degradation of methylene blue (MB) with air as the oxidant under visible light irradiation and dark condition. The results indicated that the prepared nanocrystalline TiO2 thin film had good crystalline and uniform particle size distribution. According to the degradation results of MB, various homo/hetero (M-M)Pc can sensitize nanocrystalline TiO2 thin films and improve their photocatalytic activity under visible light irradiation. The catalytic activity of hetero (M-M)Pc/nanocrystalline TiO2 thin films were more effective than that of homo (M-M)Pc under both visible light irradiation and dark condition, and the air purging was essential in degradation of MB. Therefore, these (M-M)Pc/nanocrystalline TiO2 thin films can be applied to the degradation of MB as a promising catalyzer.