Bai Jianguo, Wang Jun, Zheng Hao, Zhao Xiaoli, Wu Pengyan, Pei Li, Wang Jian
Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou, Jiangsu, 221116, P. R. China.
School of Environmental and Natural Resources, Zhejiang University of Science and Technology, Hangzhou, Zhejiang, 310023, P. R. China.
Small. 2023 Nov;19(48):e2305024. doi: 10.1002/smll.202305024. Epub 2023 Aug 3.
Photocatalytic hydrogen production via water splitting is the subject of intense research. Photoinduced electron transfer (PET) between a photosensitizer (PS) and a proton reduction catalyst is a prerequisite step and crucial to affecting hydrogen production efficiency. Herein, three photoactive metal-organic framework (MOF) systems having two different PET processes where PS and Co(II) centers are either covalently bonded or coexisting to drive photocatalytic H production are built. Compared to these two intramolecular PET systems including Co -Zn-PDTP prepared from the post-synthetic metalation toward uncoordinated pyridine N sites of Zn-PDTP and sole cobalt-based MOF Co-PDTP, the Co (bpy) @Zn-PDTP system impregnated by molecular cocatalyst possessing intermolecular PET process achieves the highest H evolution rate of 116.8 mmol g h over a period of 10 h, about 7.5 and 9.3 times compared to Co -Zn-PDTP and Co-PDTP in visible-light-driven H evolution, respectively. Further studies reveal that the enhanced photoactivity in Co (bpy) @Zn-PDTP can be ascribed to the high charge-separation efficiency of Zn-PDTP and the synergistic intermolecular interaction between Zn-PDTP and cobalt complexes. The present work demonstrates that the rational design of PET process between MOFs and catalytic metal sites can be a viable strategy for the development of highly efficient photocatalysts with enhanced photocatalytic activities.
通过水分解进行光催化产氢是当前研究的热点。光敏剂（PS）与质子还原催化剂之间的光致电子转移（PET）是一个先决步骤，对影响产氢效率至关重要。在此，构建了三种具有两种不同PET过程的光活性金属有机框架（MOF）体系，其中PS和Co（II）中心通过共价键结合或共存以驱动光催化产氢。与这两种分子内PET体系（包括通过对Zn-PDTP未配位吡啶N位点进行后合成金属化制备的Co-Zn-PDTP和单一钴基MOF Co-PDTP）相比，具有分子间PET过程的分子助催化剂浸渍的Co（bpy）@Zn-PDTP体系在10小时内实现了最高的析氢速率116.8 mmol g⁻¹ h⁻¹，在可见光驱动析氢中分别约为Co-Zn-PDTP和Co-PDTP的7.5倍和9.3倍。进一步的研究表明，Co（bpy）@Zn-PDTP中增强的光活性可归因于Zn-PDTP的高电荷分离效率以及Zn-PDTP与钴配合物之间的协同分子间相互作用。目前的工作表明，合理设计MOF与催化金属位点之间的PET过程可以成为开发具有增强光催化活性的高效光催化剂的可行策略。
