Water-soluble magnetic nanoparticles functionalized with photosensitizer for photocatalytic application

We report a novel photofunctional magnetic nanoparticle that is strategically designed and prepared by simple modification process. Photofunctionality is provided by the photosensitizer (PS) of [5,15-bis(phenyl)-10,20-bis(4-methoxycarbonylphenyl)porphyrin]platinum that generates singlet oxygen in high quantum yield. The PS molecules are covalently bonded to the surface of magnetic nanoparticles. Microstructure and magnetic and photophysical properties of the photofunctional magnetic nanoparticles are investigated by transmission electron microscopy, vibrating sample magnetometry, and time-resolved spectroscopic methods. The results show that the immobilized PS molecules retain their optical and functional properties including the high efficiency of singlet oxygen generation. Generation quantum yield (Φ_Δ) and releasing yield (η_Δ) of singlet oxygen from the prepared photofunctional magnetic nanoparticles are 0.47 and 0.42, respectively. Furthermore, the photofunctional magnetic nanoparticles have good solubility and stability in water, which are induced by the surface modification process. The photocatalytic experiment is demonstrated by utilizing the oxidation reaction of 2,4,6-trichlorophenol with the photofunctional magnetic nanoparticles.