Synthesis, characterization, and activity of a covalently anchored heterogeneous perylene diimide photocatalyst

Abstract The consecutive two-photon photocatalytic behavior of perylene diimide (PDI) enables it to catalyze photoreduction reactions that are thermodynamically unfavorable via single-photon processes. In this work, we developed a heterogeneous PDI photocatalyst by covalently binding PDI molecules on the surface of nanosilica. This photocatalyst structure overcomes the intrinsic limitation of the low solubility of PDI, but retains its consecutive two-photon photocatalytic property. Detailed characterization of the photocatalyst by techniques such as thermogravimetric analysis, solid-state nuclear magnetic resonance spectroscopy, and Fourier transform infrared spectroscopy indicated that the PDI molecules were anchored covalently on the surface of nanosilica. The obtained photocatalyst reduced aryl halides under visible-light irradiation in polar organic solvent and in water. The present study provides a promising strategy to realize two-photon activity of PDI in common solvents for photocatalytic applications.