Liu Jiaying, Li Jingjun, Lin Zujin, Ye Shihua, Lin Wenlie, Yang Xue, Gao Shui-Ying, Cao Rong
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China.
College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China.
Small. 2025 Feb;21(7):e2411315. doi: 10.1002/smll.202411315. Epub 2025 Jan 2.
Covalent organic frameworks (COFs) are a promising platform for heterogeneous photocatalysis due to their stability and design diversity, but their potential is often restricted by unmanageable targeted excitation and charge transfer. Herein, a bimetallic COF integrating photosensitizers and catalytic sites is designed to facilitate locally ultrafast charge transfer, aiming to improve the photocatalytic reduction of CO. The strategy uses a "one-pot" method to synthesize the bimetallic COF (termed PBCOF) through in situ Schiff-base condensation of Pyrene with MBpy (M = Ru, Re) units. In this structure, Ru and Re are anchored within bipyridine as the photosensitive center and catalytic site, respectively. The bimetallic architecture of PBCOF significantly boosts the photocatalytic efficiency for CO reduction, achieving an impressive CO yield of 8306.6 µmol g h with 99.8% selectivity, surpassing most reported COF materials. This improvement is attributed to the localized ultrafast charge transfer (0.23 ps) from Ru to Re, as demonstrated by femtosecond transient absorption spectroscopy (TAS). Further investigations demonstrate its heterogeneous feature, showcasing exceptional long-term stability and recyclability. This study represents a versatile approach for designing bimetallic COFs with ultrafast charge transfer, paving the pathway for advancements in artificial photosynthesis.
共价有机框架（COFs）因其稳定性和设计多样性，是一种很有前景的多相光催化平台，但其潜力常常受到难以控制的靶向激发和电荷转移的限制。在此，设计了一种整合光敏剂和催化位点的双金属COF，以促进局部超快电荷转移，旨在提高CO的光催化还原性能。该策略采用“一锅法”，通过芘与MBpy（M = Ru，Re）单元原位席夫碱缩合反应合成双金属COF（称为PBCOF）。在这种结构中，Ru和Re分别作为光敏中心和催化位点锚定在联吡啶内。PBCOF的双金属结构显著提高了CO还原的光催化效率，实现了8306.6 µmol g⁻¹ h⁻¹的CO产率，选择性达99.8%，超过了大多数已报道的COF材料。飞秒瞬态吸收光谱（TAS）表明，这种提高归因于从Ru到Re的局部超快电荷转移（0.23 ps）。进一步研究证明了其多相特性，展示了出色的长期稳定性和可回收性。这项研究代表了一种设计具有超快电荷转移的双金属COF的通用方法，为人工光合作用的进展铺平了道路。
