C₆₀ aminofullerene-magnetite nanocomposite designed for efficient visible light photocatalysis and magnetic recovery

A magnetically recyclable photosensitizing system for harnessing solar energy for water treatment and disinfection is reported. This system comprises C₆₀ aminofullerene as a sensitizer for singlet oxygenation and functionalized mesoporous silica (msu-f SiO₂) encapsulating magnetite nanoparticles (msu-SiO₂/mag) as a magnetically separable host. Rapid degradation of furfuryl alcohol (FFA) (a singlet oxygen (¹O ₂) probe) under visible-light irradiation along with the kinetic retardation of FFA decomposition in the presence of ¹O₂ quenchers suggests that the visible-light activity of C₆₀ aminofullerene-derivatized msu-SiO₂/mag (C₆₀/msu-SiO ₂/mag) is related to the photosensitization of ¹O ₂. On the other hand, the use of SiO₂ gel and fumed SiO₂ as magnetic supports drastically reduced the photosensitized generation of ¹O₂, which is ascribed to the absence of an ordered pore structure in the alternative silica support, resulting in an uncontrolled growth of Fe₃O₄ and an aggregation of the fullerenes on the SiO₂ gel and fumed SiO₂. Significant ¹O₂ production using C₆₀/msu-SiO ₂/mag led to the effective oxidation of emerging pharmaceutical contaminants and inactivation of MS-2 bacteriophage under visible-light irradiation. Magnetic recovery and the subsequent reuse of the composite did not cause any significant loss in the photosensitizing activity of C ₆₀/msu-SiO₂/mag, demonstrating its potential for catalytic applications.