Chemical Engineering Journal ( IF 13.3 ) Pub Date : 2023-01-07 , DOI: 10.1016/j.cej.2023.141360 Li-Juan Gong , Li-Yao Liu , Shao-Shuai Zhao , Shuai-Long Yang , Duan-Hui Si , Qiu-Jin Wu , Qiao Wu , Yuan-Biao Huang , Rong Cao
Charge transfer efficiency between discrete photosensitizers and catalytic sites is a key limiting factor in artificial photosynthesis. It is highly desirable but challenging to efficiently combine the two sections into an integration system and get insight into the kinetics and mechanisms. Here in, the photosensitizer [Ru(bpy)3]2+ (bpy = 2,2′-bipyridine) and active cobalt porphyrin (Co-Por) sites were integrated into a covalent organic framework (COF), named COF-RuBpy-Co, for efficient charge transfer and photocatalytic CO2 reduction. The catalyst COF-RuBpy-Co exhibited excellent CO2 photoreduction activity towards CO production with a rate of 547 μmol g−1h−1, which is 1.4-fold enhancement over the physical mixture of Ru(bpy)3Cl2 and COF-Bpy-Co. In situ X-ray photoelectron spectroscopy combined with theoretical calculation results revealed that COF-RuBpy-Co achieved efficient photoelectron transfer from [Ru(bpy)3]2+ to cobalt porphyrin. More importantly, transient absorption spectroscopy indicated that the covalent linking [Ru(bpy)3]2+and Co-Por units realized a faster charge transfer (44.2 ps) over the large π-conjugated system. This work provides vital insights into the charge carrier transfer process and demonstrates the potential of COFs as a platform in artificial photosynthesis.
中文翻译:
通过键在共价有机框架中快速转移电荷以增强光催化 CO2 还原
离散光敏剂和催化位点之间的电荷转移效率是人工光合作用的关键限制因素。将这两个部分有效地组合成一个集成系统并深入了解动力学和机制是非常可取但具有挑战性的。在这里,光敏剂 [Ru(bpy) 3 ] 2+ (bpy = 2,2'-联吡啶) 和活性钴卟啉 (Co-Por) 位点被整合到共价有机骨架 (COF) 中,命名为 COF-RuBpy- Co,用于有效的电荷转移和光催化 CO 2还原。催化剂 COF-RuBpy-Co 对 CO 生产表现出优异的 CO 2光还原活性,速率为 547 μmol g −1 h −1,这是 Ru(bpy) 3 Cl 2和 COF-Bpy-Co 的物理混合物的 1.4 倍增强。原位X射线光电子能谱结合理论计算结果表明,COF-RuBpy-Co实现了从[Ru(bpy) 3 ] 2+到钴卟啉的高效光电子转移。更重要的是,瞬态吸收光谱表明共价连接 [Ru(bpy) 3 ] 2+和 Co-Por 单元在大型 π 共轭系统上实现了更快的电荷转移 (44.2 ps)。这项工作提供了对电荷载流子转移过程的重要见解,并展示了 COF 作为人工光合作用平台的潜力。