Tuning Protonation Microenvironments in Covalent Organic Frameworks for Enhanced Photocatalytic Hydrogen Evolution

Researchers at Fuzhou University have made a significant breakthrough in the field of nanotechnology-photocatalytics by developing a new strategy to tune the protonation microenvironment and electronic structure of covalent organic frameworks (COFs). This innovative approach, known as "edge-linker engineering," involves incorporating distinct edge linkers into one-dimensional (1D) imine-linked COFs to enhance their photocatalytic performance. The study, published in ACS Catalysis, demonstrates that the sulfur-containing edge linker in COF-SDA significantly enhances charge delocalization and facilitates the hydrogen reduction process, outperforming its analogs.

Key Takeaways:

• Researchers at Fuzhou University have developed an "edge-linker engineering" strategy to tune the protonation microenvironment and electronic structure of 1D imine-linked COFs, leading to enhanced photocatalytic performance.
• The sulfur-containing edge linker in COF-SDA significantly enhances charge delocalization and facilitates the hydrogen reduction process, outperforming its analogs.
• The research establishes a comprehensive structure-function relationship among edge-site design, protonation behavior, and photocatalytic activity in 1D COFs, providing a molecular design paradigm for developing polymer photocatalysts for solar-to-hydrogen conversion.
• The study was supported by the National Key R&D Program of China, the National Natural Science Foundation of China (NSFC), and the Natural Science Foundation of Fujian Province.
• The research team consisted of Xiong Chen, Pan-Ke Zhou, Cong Zhang, Yuxing Huang, Ziyue Yu, Chao Lin, Chao Zhang, Qiqi Sun, Sibo Wang, Caihong Liang, Yeng Ming Lam, Yupeng Song, Xiao-Rui Ren, and Dong Wang.
• The study highlights the critical role of edge-linker-mediated electronic modulation in enhancing the photocatalytic performance of COFs.

Statistics:

• The hydrogen evolution rate under visible-light irradiation using ascorbic acid as the protonation reagent was significantly enhanced in COF-SDA, outperforming its analogs.
• The sulfur-containing edge linker in COF-SDA exhibited a hydrogen binding affinity of 0.5 eV, highlighting the critical role of edge-linker-mediated electronic modulation.
• The study demonstrated that the protonation microenvironment and electronic structure of COFs can be tuned by incorporating distinct edge linkers, leading to enhanced photocatalytic performance.
• The research established a comprehensive structure-function relationship among edge-site design, protonation behavior, and photocatalytic activity in 1D COFs.

Sources:

• ACS Catalysis, 2025.
• National Key R&D Program of China.
• National Natural Science Foundation of China (NSFC).
• Natural Science Foundation of Fujian Province.
• Fuzhou University, College of Chemistry, State Key Lab Chem Nbc Hazards Protect, Fuzhou 350116, People's Republic of China.