Novel polymers with cobalt(II)phthalocyanine moieties as effective heterogeneous photocatalysts for visible-light-driven photodegradation of organic dyes in aqueous solutions

Phthalocyanines (Pcs) are suitable for pigment-based applications owing to their dense colors as well as they are used in oxidation and reduction reactions. In this study, partially fluorinated polystyrene (F-pSt) and partially fluorinated polymethyl methacrylate (F-pMMA) polymers were used to support novel unsymmetrical cobalt(II) phthalocyanine(CoPc) via Huisgen's Cu(I)-catalyzed 1,3-dipolar cycloaddition, referred to as the “click chemistry”, and the resulting new structures were elucidated with various well-known spectroscopic techniques. The photocatalytic activity of the novel heterogeneous F-pStCoPc and F-pMMACoPc catalysts were estimated for the degradation of two well-known dyes, methylene blue (MB) and methyl violet (MV) in aqueous medium under illumination with visible light (λ > 400 nm) with or without hydrogen peroxide and/or air at specified pH values. UV–vis spectrophotometry was employed to determine the concentration of the dyes. MB and MV (10 ppm, 25 mL) were completely dissociated (photochemically) with 20 mg of the reported catalyst in 60 min under atmospheric air. The catalyst reported herein is highly recyclable and does not require the presence of well-known semiconductors like ZnO/TiO₂. Besides, the catalyst is stable over a long time and it is recyclable up to five times (without any deactivation). It has been concluded that this procedure will have a bright future for wastewater treatment and green chemistry.