Ion-Mediated Self-Assembly of Graphene Oxide and Functionalized Perylene Diimides into Hybrid Materials with Photocatalytic Properties.

A novel ion-mediated self-assembly method was applied for integration of graphene oxide (GO), propanoic- and glutaric-substituted perylenes (glu-PDI and PA-PDI), and Zn (OAc)₂ into new hybrid materials with photocatalytic properties. The structuring of chromophores through coordination bonding on the GO surface is controlled by the chemistry of the PDI linkers. Four-substituted glu-PDI forms consolidated microporous particles, whereas di-substituted PA-PDI binds with GO into a macroporous gel-like structure. The GO/PDI controls without Zn²⁺ ions form only non-integrated dispersions. Both hybrids can initiate photodestruction of 1,5-dihydroxynaphtalene (DHN) due to the effective charge separation between the PDI components and GO by generating hydroxyl radicals determined by luminescent probing with terephthalic acid. The reduction mechanism of photodegradation was confirmed by MALDI-TOF spectroscopy. The structure of the hybrids controls the rate of photodegradation process. The glu-PDI-based photocatalyst shows a smaller rate of photoreduction of 3.3 × 10⁻² min⁻¹ than that with PA-PDA (4 × 10⁻² min⁻¹) due to diffusion limitations. Our results suggest that the ion-mediated synthesis is a useful and rational alternative for the conventional synthesis of GO-based functional hybrid materials through aromatic stacking between the graphene oxide and organic chromophores to produce new affordable and efficient photocatalysts. [ABSTRACT FROM AUTHOR]