中国科学技术大学熊宇杰团队报道了在二维光催化剂和助催化剂之间建立不对称Zn–N₃桥，用于高效合成H₂O₂的定向电荷转移。相关研究成果于2024年10月8日发表在国际知名学术期刊《德国应用化学》。

二维（2D）聚合物半导体是一类有前景的光催化剂。然而，促进它们层间电荷转移以抑制平面内电荷复合，并提高量子效率仍然具有挑战性。尽管迄今为止已经开发了一些策略，如π-π堆叠和范德华相互作用，但仍然无法实现有向层间电荷转移。

该文中，研究人员报告了一种形成不对称Zn-N₃单元的策略，该单元可以将氮（N）掺杂的碳层与聚合物氮化碳纳米片（C₃N₄-Zn-N（C））桥接，以应对这一挑战。对称性破坏的Zn-N₃部分具有不对称的局部电荷分布，能够实现C₃N₄光催化剂和氮掺杂碳助催化剂之间的定向界面电荷转移。

飞秒瞬态吸收光谱表明，界面不对称的Zn-N₃键桥可以显著增强电荷分离。因此，设计的C₃N₄-Zn-N（C）催化剂表现出显著增强的H₂O₂光合作用活性，优于大多数报道的C₃N₄基催化剂。

该项工作强调了在分子水平上定制聚合物光催化剂界面化学键通道，以实现有效空间电荷分离的重要性。

附：英文原文

Title: Building Asymmetric Zn–N3 Bridge between 2D Photocatalyst and Co-catalyst for Directed Charge Transfer toward Efficient H2O2 Synthesis

Author: Weikang Wang, Rong Liu, Jianjun Zhang, Tingting Kong, Lele Wang, Xiaohui Yu, Xiaomin Ji, Qinqin Liu, Ran Long, Zhou Lu, Yujie Xiong

Issue&Volume: 2024-10-08

Abstract: Two-dimensional (2D) polymeric semiconductors are a class of promising photocatalysts; however, it remains challenging to facilitate their interlayer charge transfer for suppressed in-plane charge recombination and thus improved quantum efficiency. Although some strategies, such as π-π stacking and van der Waals interaction, have been developed so far, directed interlayer charge transfer still cannot be achieved. Herein, we report a strategy of forming asymmetric Zn–N3 units that can bridge nitrogen (N)-doped carbon layers with polymeric carbon nitride nanosheets (C3N4-Zn-N(C)) to address this challenge. The symmetry-breaking Zn–N3 moiety, which has an asymmetric local charge distribution, enables directed interfacial charge transfer between the C3N4 photocatalyst and the N-doped carbon co-catalyst. As evidenced by femtosecond transient absorption spectroscopy, charge separation can be significantly enhanced by the interfacial asymmetric Zn–N3 bonding bridges. As a result, the designed C3N4-Zn-N(C) catalyst exhibits dramatically enhanced H2O2 photosynthesis activity, outperforming most of the reported C3N4-based catalysts. This work highlights the importance of tailoring interfacial chemical bonding channels in polymeric photocatalysts at the molecular level to achieve effective spatial charge separation.

DOI: 10.1002/anie.202415800

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202415800