Zhong Xiang, Zhu Yuxiang, Wang Yan, Jia Zhengtao, Jiang Meng, Sun Qiufan, Yao Jianfeng
Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China.
Small. 2024 Aug;20(35):e2402219. doi: 10.1002/smll.202402219. Epub 2024 Apr 18.
In this work, an intramolecular carbon nitride (CN)-based quaternary homojunction functionalized with pyridine rings is prepared via an in situ alkali-assisted copolymerization strategy of bulk CN and 2-aminopyridine for efficient visible light hydrogen generation. In the obtained structure, triazine-based CN (TCN), heptazine-based CN (HCN), pyridine unit incorporated TCN, and pyridine ring inserted HCN constitute a special multicomponent system and form a built-in electric field between the crystalline semiconductors by the arrangement of energy band levels. The electron-withdrawing function of the conjugated heterocycle can trigger the skeleton delocalization and edge induction effect. Highly accelerated photoelectron-hole transfer rates via multi-stepwise charge migration pathways are achieved by the synergistic effect of the functional group modification and molecular quaternary homojunction. Under the addition of 5 mg 2-aminopyridine, the resulting homojunction framework exhibits a significantly improved hydrogen evolution rate of 6.64 mmol g h with an apparent quantum efficiency of 12.27% at 420 nm. Further, the catalyst verifies its potential commercial value since it can produce hydrogen from various real water environments. This study provides a reliable way for the rational design and fabrication of intramolecular multi-homojunction to obtain high-efficient photocatalytic reactions.
在这项工作中，通过本体碳氮化物（CN）与2-氨基吡啶的原位碱辅助共聚策略，制备了一种用吡啶环功能化的分子内碳氮化物（CN）基四元同质结，用于高效可见光制氢。在所得结构中，基于三嗪的CN（TCN）、基于七嗪的CN（HCN）、并入吡啶单元的TCN和插入吡啶环的HCN构成了一个特殊的多组分体系，并通过能带水平的排列在晶体半导体之间形成了内建电场。共轭杂环的吸电子功能可引发骨架离域和边缘诱导效应。通过官能团修饰和分子四元同质结的协同效应，实现了通过多步电荷迁移途径的高度加速的光电子-空穴转移速率。在添加5mg 2-氨基吡啶的情况下，所得同质结框架的析氢速率显著提高，达到6.64mmol g⁻¹ h⁻¹，在420nm处的表观量子效率为12.27%。此外，该催化剂验证了其潜在的商业价值，因为它可以从各种实际水环境中产生氢气。这项研究为合理设计和制备分子内多同质结以获得高效光催化反应提供了一条可靠的途径。
