Increasing Donor–Acceptor Interactions and Particle Dispersibility of Covalent Triazine Frameworks for Higher Crystallinity and Enhanced Photocatalytic Activity

Abstract

Covalent triazine frameworks (CTFs) have recently emerged as an efficient class of photocatalysts due to their structural diversity and excellent stability. Nevertheless, the synthetic reactions of CTFs have usually suffered from poor reversibility, resulting in a low crystallinity of the materials. Here, we report the introduction of methoxy groups on the monomer 2,5-diphenylthiazolo [5,4-d]thiazole to reinforce interlayer π−π interactions of the resulting donor−acceptor type CTFs, which improved crystallinity, further increasing the visible light absorption range and allowing for efficient separation and transport of carriers. The morphology is strongly correlated to the wettability, which has a significant impact on the mass transfer capacity and photocatalytic activity in the photocatalytic reaction. To further improve crystallinity and photocatalytic activity, CTF-NWU-T3 photocatalysts in a bowl shape were prepared using a SiO 2 template. The energy band structure, photocatalytic hydrogen evolution, and pollutant degradation efficiency of involved materials were investigated. The donor−acceptor type CTF-NWU-T3 with a bowl-shaped morphology, synthesized using the template method and the introduction of methoxy groups, exhibited an excellent photocatalytic hydrogen production rate of 32064 μmol•h −1 •g −1 . This study highlights the significance of improving donor−acceptor interactions and increasing the dispersibility of catalyst particles in dispersion to enhance the photocatalytic activity of heterogeneous photocatalysts.

Enhanced Photocatalytic Activity of Calix[4]arene-Based Donor–Acceptor Covalent Organic Frameworks by Dual Cocatalysts

“…Calix­[ n ]­arene units are characterized by a high negative surface charge along with excellent thermal and optical stability. Heterocyclic compounds, such as TzTz, are commonly used as electron acceptors due to their favorable high electron mobility. − Subsequently, the linker 1,4-phthalaldehyde (PA) was employed to react with C4A-NH 2 to synthesize C4A-PA-COF with a non-D–A structure for comparison. Following the synthesis of two crystalline C4A-COFs, their structures and photoelectric properties were comprehensively characterized.…”