西安交通大学何刚团队报道了硒紫原基四聚环烷的定向电子流增强可见光驱动析氢。相关研究成果于2024年7月23日发表在《德国应用化学》。

光催化剂中的定向电子流能够实现有效的电荷分离，这对于H₂生产的有效光催化至关重要。

该文中，研究人员报道了一类新型的掺入了联吡啶Pt（II）和硒生物素的四阳离子环烷（7）。X射线单晶结构显示，7不仅固定了其单个单元之间的距离和空间位置，而且还表现出盒状刚性缺电子腔。此外，在7和二茂铁之间观察到主客体识别现象，在MeCN中形成1:1化学计量比的主客体络合物。由于含有两个硒生物素（SeV²⁺）单元，7具有良好的氧化还原性能、窄能隙和在可见光范围（370-500nm）内的强吸收。

同时，飞秒瞬态吸收（fs-TA）表明，由于刚性环烷和电子结构的形成，7具有稳定的双自由基、高效的电荷分离，并促进定向电子流以实现高效的电子转移。然后，将7应用于可见光驱动的氢气释放，具有高氢气产量（132μmol）、产生率（11μmol/h）、周转数（221）和表观量子产率（1.7%），为太阳能转换提供了一种简化有效的光催化策略。

附：英文原文

Title: Directional Electron Flow in a Selenoviologen-Based Tetracationic Cyclophane for Enhanced Visible-Light-Driven Hydrogen Evolution

Author: Naiyao Li, Yawen Li, Zengrong Wang, Tianle Cao, Chenjing Liu, Hongyue Wang, Guoping Li, Gang He

Issue&Volume: 2024-07-23

Abstract: Directional electron flow in the photocatalyst enables efficient charge separation, which is essential for efficient photocatalysis of H2 production. Here, we report a novel class of tetracationic cyclophanes (7) incorporating bipyridine Pt(II) and selenoviologen. X-ray single-crystal structures reveal that 7 not only fixes the distances and spatial positions between its individual units but also exhibits a box-like rigid electron-deficient cavity. Moreover, host-guest recognition phenomena are observed between 7 and ferrocene, forming host-guest complexes with a 1:1 stoichiometry in MeCN. 7 exhibits good redox properties, narrow energy gaps, and strong absorption in the visible range (370-500 nm) due to containing two selenoviologen (SeV2+) units. Meanwhile, the femtosecond transient absorption (fs-TA) reveals that 7 has stabilized dicationic biradical, efficient charge separation, and facilitates directional electron flow to achieve efficient electron transfer due to the formation of rigid cyclophane and electronic architecture. Then, 7 is applied to visible-light-driven hydrogen evolution with high hydrogen production (132 μmol), generation rate (11 μmol/h), turnover number (221), and apparent quantum yield (1.7%), which provides a simplified and efficient photocatalytic strategy for solar energy conversion.

DOI: 10.1002/anie.202410525

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202410525