Zhang Ling, Wang Congxu, Jiang Qike, Lyu Pengbo, Xu Yuxi
School of Engineering, Westlake University, Hangzhou 310024, Zhejiang Province, China.
Instrumentation and Service Center for Physical Sciences, Westlake University, Hangzhou 310024, Zhejiang Province, China.
J Am Chem Soc. 2024 Oct 30;146(43):29943-29954. doi: 10.1021/jacs.4c12339. Epub 2024 Oct 17.
The development of green and efficient hydrogen peroxide (HO) production is of great interest but remains challenging. Herein, we develop a new and simple strategy via locking the coplanarity in highly crystalline covalent triazine frameworks (CTFs) to remarkably boost direct photosynthesis of HO from oxygen and water. The exfoliated ultrathin 2D-CTF nanosheets exhibit excellent photocatalytic HO evolution with an ultrahigh solar-to-chemical efficiency of 0.91% and a superb apparent quantum yield of 16.8% at 420 nm, surpassing all previous CTFs and most of the metal-free photocatalysts ever reported. Our detailed experimental and theoretical studies reveal that the spatially locked structure in the crystalline CTF photocatalyst can not only greatly enhance the separation and transfer of photoexcited charge-carriers for promoting HO photogeneration but also alter the local electronic structures that unexpectedly turn water oxidation from a four-electron route to a two-electron pathway, resulting in a 100% atom utilization efficiency. This work provides valuable insights into the designed synthesis of highly efficient metal-free photocatalysts and precise control over photocatalytic reaction pathways in organic materials.
绿色高效生产过氧化氢（H₂O₂）备受关注，但仍具挑战性。在此，我们通过锁定高度结晶的共价三嗪框架（CTF）中的共面性，开发了一种新颖且简单的策略，以显著促进由氧气和水直接光合成H₂O₂。剥离的超薄二维CTF纳米片表现出优异的光催化H₂O₂生成性能，在420nm处具有0.91%的超高太阳能到化学能效率和16.8%的出色表观量子产率，超过了此前所有的CTF以及大多数已报道的无金属光催化剂。我们详细的实验和理论研究表明，结晶CTF光催化剂中的空间锁定结构不仅能极大地增强光激发电荷载流子的分离和转移以促进H₂O₂光生成，还能改变局部电子结构，意外地将水氧化从四电子途径转变为两电子途径，从而实现100%的原子利用效率。这项工作为高效无金属光催化剂的设计合成以及有机材料中光催化反应途径的精确控制提供了有价值的见解。
