Quinoline-based porous organic polymers with divergent photocatalytic properties

Introduction

The transition to a greener and more renewable productive model has been raised as a main challenge for science during recent decades. Reducingdependence on petrol fuels and finding new sources for industrial chemical precursors requires brand-new approaches with a lower or, ideally, no carbon footprint. In this context, photocatalysis has emerged as a greatly encouraging solution. Among the most promising heterogeneous photocatalysts, we can find reticular organic materials such as Covalent Organic Frameworks (COFs) and related amorphous materials, such as Covalent Triazine Frameworks (CTFs) or Conjugated Microporous Polymers (CMPs).

Results

A variety of conjugated microporous polymers (CMPs) and covalent triazine frameworks (CTFs) have been recently synthesized in our laboratory. A particular family of such materials is that containing quinoline fragments acting as photocatalytic moieties. Predetermined series of CMPs and CTFs with similar structural and photophysical properties show divergent photocatalytic activities for environmentally relevant reactions such as hydrogen evolution and the oxidation of furfural derivatives. Different catalytic behaviors arise from differences in their electronic structures, which were analyzed from both experimental and theoretical studies.

Conclusions

The esults obtained suggest that nitrogen doping and electron-donating groups play a critical role in tuning the photocatalytic properties of organic materials, offering a powerful strategy for designing building blocks in heterogeneous organic photocatalysts. This underscores the versatility and broad applicability of nitrogen-enriched materials for various photocatalytic processes, from oxidation reactions to hydrogen generation.