Yan Jinyu, Li Yuan, Luo XiaoLi, Zhang Zihan, Xu Hua, Yuan Hong, Ouyang Shuxin
Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction, College of Chemistry, Central China Normal University, Wuhan 430079, China.
School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Wuhan 430205, China.
J Colloid Interface Sci. 2025 Dec;699(Pt 2):138285. doi: 10.1016/j.jcis.2025.138285. Epub 2025 Jun 25.
Covalent organic frameworks (COFs) have been emerged as a kind of promising photocatalysts for the artificial synthesis of HO, but the efficiency is largely limited by the subpar transport of photogenerated carriers and sluggish surface O reduction process. Here, via tuning the functional group of donor monomer from phenyl into alkynyl group, two donor-acceptor (D-A) type covalent triazine frameworks (BT-COF and TT-COF) were synthesized, of which the triazine moiety acted as the principal active center for O reduction. Due to the high-density electrons of alkynyl group, experimental results revealed that the BT-COF catalyst owned the facilitated O adsorption and superior charge transportation, in addition to more negative reduction potential. Accordingly, the BT-COF catalyst exhibited relatively a high photocatalytic HO production rate (7200 μmol h g) under visible light irradiation, about 1.5 times of the TT-COF catalyst. The wavelength-dependent apparent quantum yield test verified that the HO production over the BT-COF catalyst was the semiconductor-based photocatalysis. In-situ FTIR spectra further confirmed that the HO generation went through a two-step single-electron O reduction route, in which •O existed as intermediate. This study provides insights into the superior O conversion for HO photosynthesis over D-A COFs by optimizing the functional groups of donor monomers.
共价有机框架材料（COFs）已成为用于人工合成过氧化氢的一类有前景的光催化剂，但其效率在很大程度上受到光生载流子传输不佳和表面氧还原过程缓慢的限制。在此，通过将供体单体的官能团从苯基调整为炔基，合成了两种供体-受体（D-A）型共价三嗪框架材料（BT-COF和TT-COF），其中三嗪部分作为氧还原的主要活性中心。由于炔基的高密度电子，实验结果表明，BT-COF催化剂除了具有更负的还原电位外，还具有促进的氧吸附和优异的电荷传输性能。因此，BT-COF催化剂在可见光照射下表现出相对较高的光催化过氧化氢产率（7200 μmol h g），约为TT-COF催化剂的1.5倍。波长依赖性表观量子产率测试证实，BT-COF催化剂上的过氧化氢生成是基于半导体的光催化过程。原位傅里叶变换红外光谱进一步证实，过氧化氢的生成经历了两步单电子氧还原途径，其中•O作为中间体存在。本研究通过优化供体单体的官能团，为D-A型COFs在过氧化氢光合作用中优异的氧转化提供了见解。
