Tetraamino-zinc phthalocyanine covalently bound to benzoic acid-functionalized graphene composites for highly efficient visible light photocatalytic activities

Abstract

A composite of 1,8,15,22-tetraamino zinc phthalocyanine (ZnTAPc) covalently bound to benzoic acid-functionalized graphene (BFG) was used for photodegradation of rhodamine B (RhB) for the first time. The formation of an amido bond between ZnTAPc and BFG has been confirmed by Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. For photodegradation of RhB in water, the as-prepared ZnTAPc–10% BFG composite exhibits much stronger visible-light catalytic activity than pure ZnTAPc. This effect can be attributed to the high pollutant adsorption performance of ZnTAPc–BFG, the increased light absorption and the effective charge transfer and separation. In addition, the excess BFG (15%) in the composite results in a significant decrease in photocatalytic efficiency, due to the decrease of the adsorption sites and catalytic active centers. The ZnTAPc–10% BFG composite photocatalyst, with high photocatalytic efficiency and reusability, is potentially applicable in environmental purification of organic pollutants.