Anthraquinone‐Engineered Thiophene‐Based Nanotube‐Like Porous Aromatic Framework as a Robust and Efficient Bifunctional Photocatalyst for C─H Cyanation of Tertiary Amines and Hydrogen Peroxide Generation

Abstract

ABSTRACT The development of stable organic semiconductor photocatalysts—those capable of withstanding harsh conditions while maintaining high activity—remains a significant challenge. To this end, this study proposes an anthraquinone engineering strategy that aims to simultaneously enhance both structural stability and catalytic efficiency of organic semiconductors for photocatalysis. Specifically, 1,3,5‐tri(thiophen‐2‐yl)benzene (TTB)‐based porous aromatic frameworks (PAFs) (TTB‐PAFs) are optimized by linking anthraquinone fragments via carbon‐carbon bond formation. The unique electron distribution, abundant active sites, nanotube‐like micromorphology, and robust carbon‐carbon bonding character of the optimized TTB‐PAF jointly facilitate the charge separation/transfer, mass transportation, and stability during photocatalysis. Remarkably, these result in the optimal C─H cyanation of tertiary amines over the PAF‐396 photocatalyst, achieving excellent yields (up to 99%), good substrate adaptability (18 examples), and good recyclability (10 cycles), thereby surpassing the performance of reported porous organic semiconductor materials under similar conditions. Furthermore, PAF‐396 also achieves efficient photosynthesis of hydrogen peroxide (H 2 O 2 ) with a high synthesis rate of 5154 µmol g −1 h −1 from air and water without a sacrificial reagent under blue LED lamp irradiation.