Hydrogen-bonded organic framework for red light-mediated photocatalysis

The development of heterogeneous molecule-based catalysts for red light-mediated photocatalysis is still challenging due to the improper light absorption for most materials and the photoactivity deactivation for solid assembly. Herein, red light photocatalysis with a hydrogen-bonded organic framework (HOF) is established. This HOF, named HOF-66, is formed from the self-assembly of guanine-decorated naphthalenediimide (NDI) molecule through hydrogen-bonded guanine-quadruplex nodes, showing square grid supramolecular layers confirmed by powder X-ray diffraction analysis. In contrast to unsubstituted NDI HOF, introduction of ethylamino groups to NDI core in HOF-66 tunes strong electronic maximum absorption peak to 619 nm, allowing red light photocatalysis of singlet oxygen evolution proved by 1,3-diphenylisobenzofuran degradation and electron spin resonance determination. Particularly, under the same conditions, the sulfide oxidation rate in the presence of HOF-66 was 28 times higher compared to its unsubstituted analogue. This work integrates the molecular design and aggregation effect towards the application of HOFs, opening a new gate for red light photocatalysts.

Automated summary

This study establishes a hydrogen-bonded organic framework that can be used for red light photocatalysis. By introducing ethylamino groups to the core molecule, the material is able to absorb red light at 619 nm and generate singlet oxygen, thereby enhancing the oxidation rate of sulfides.