Wei Wei, Zou Leilei, Li Jin, Hou Fengming, Sheng Zekai, Li Yihang, Guo Zhipeng, Wei Ang
State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu Key Laboratory for Biosensors, Nanjing University of Posts & Telecommunications, Nanjing 210023, China.
State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu Key Laboratory for Biosensors, Nanjing University of Posts & Telecommunications, Nanjing 210023, China; Nantong Institute of Nanjing University of Posts and Telecommunications Co. Ltd., Nantong 226001, China.
J Colloid Interface Sci. 2023 Apr 15;636:537-548. doi: 10.1016/j.jcis.2023.01.046. Epub 2023 Jan 10.
Molecular engineering of carbon nitride (CN) was considered as a suitable and compelling strategy to overcome the intrinsic imperfections and enhance photocatalytic HO production. However, the photocatalytic HO production of conventional single molecular engineering is still unsatisfactory, and the comprehension of photogenerated carrier migration and separation is still indistinct. Herein, dual molecules were engineered on CN molecular skeleton for achieving an outstanding photocatalytic rate of HO production. The photocatalytic HO production rate of the dual molecules engineered CN was up to 3320 μmol g h, which was approximately 25 times than that of the pristine CN. After the dual-molecular engineering, pyrimidine and cyano group were co-grafted. Synchronously, K ion and Na ion were co-embedded near the interlamination of CN layers. The synergistic effect of the dual molecules in CN not only restrained photogenerated carrier recombination and broadened visible light response by modulating the intrinsic energy band structure, but also enhanced the capture of the photogenerated electrons and accelerated the migration of proton. Hence, the photocatalytic 2e oxygen reduction reaction, the rate-determining step, was significantly strengthened. Additionally, caused by the positive valence band potential, the HO oxidation reaction became an indispensable role in photocatalytic HO production. This work provided a viable route to modulate the molecular skeleton of organic semiconductors and presented a promising strategy to obtain high-efficient photocatalytic HO production.
氮化碳（CN）的分子工程被认为是克服其固有缺陷并提高光催化产生羟基自由基（HO）的合适且有吸引力的策略。然而，传统单分子工程的光催化产生HO的性能仍不尽人意，对光生载流子迁移和分离的理解仍不清晰。在此，在CN分子骨架上设计了双分子，以实现出色的光催化产生HO的速率。双分子工程化的CN的光催化产生HO的速率高达3320 μmol g⁻¹ h⁻¹，约为原始CN的25倍。经过双分子工程后，嘧啶和氰基共接枝。同时，钾离子和钠离子共嵌入到CN层的层间附近。CN中双分子的协同作用不仅通过调节本征能带结构抑制了光生载流子复合并拓宽了可见光响应，还增强了对光生电子的捕获并加速了质子迁移。因此，光催化2e氧还原反应（速率决定步骤）得到了显著增强。此外，由于正价带电位，HO氧化反应在光催化产生HO中发挥了不可或缺的作用。这项工作为调节有机半导体的分子骨架提供了一条可行的途径，并提出了一种获得高效光催化产生HO的有前景的策略。
