福州大学汪思波团队报道了可见光驱动CO₂还原聚合物氮化碳的缺陷及纳米结构工程。相关研究成果发表在2024年2月6日出版的《结构化学》。

通过不含金属的聚合氮化碳（CN）半导体将阳光诱导的光催化二氧化碳（CO₂）还原为富含能源的化学品是一种很有前途的可持续太阳能燃料生产策略。然而，光生载流子在CN聚合物上的快速复合严重限制了CO₂光还原的反应效率。

该文中，研究人员以尿素为前体，通过简单的一锅热聚合策略，将具有强吸电子基团的2-氨基吡啶分子引入CN层的骨架边缘，使改性的氮化碳（ACN）具有扩展的光学捕获、丰富的氮缺陷和超薄的纳米片结构。因此，具有所需结构特征的ACN光催化剂实现了光激发电荷载流子的增强分离和迁移。

在可见光照射下，Co（bpy）₃²⁺作为助催化剂，优化的ACN样品表现出高的CO₂脱氧还原活性和高的稳定性，提供了17μmol·h^-1的CO产率，显著高于原始CN。原位漫反射红外傅立叶变换光谱法确定了参与CO₂光还原反应的关键中间体，这有助于在ACN纳米片上构建可能的光催化CO₂还原机制。

附：英文原文

Title: Defect and nanostructure engineering of polymeric carbon nitride for visible-light-driven CO2 reduction

Author: Ziruo Zhou, Wenyu Guo, Tingyu Yang, Dandan Zheng*, Yuanxing Fang, Xiahui Lin, Yidong Hou, Guigang Zhang, Sibo Wang

Issue&Volume: 2024-02-06

Abstract: Sunlight-induced photocatalytic carbon dioxide (CO2) reduction to energy-rich chemicals by metal-free polymeric carbon nitride (CN) semiconductor is a promising tactic for sustained solar fuel production. However, the reaction efficiency of CO2 photoreduction is restrained seriously by the rapid recombination of photogenerated carriers on CN polymer. Herein, we incorporate the 2-aminopyridine molecule with strong electron-withdrawing group into the skeleton edge of CN layers through a facile one-pot thermal polymerization strategy using urea as the precursor, which renders the modified carbon nitride (ACN) with extended optical harvesting, abundant nitrogen defects and ultrathin nanosheet structure. Consequently, the ACN photocatalyst with desirable structural features attains enhanced separation and migration of photoexcited charge carriers. Under visible light irradiation with Co(bpy)32+ as a cocatalyst, the optimized ACN sample manifests a high CO2 deoxygnative reduction activity and high stability, providing a CO yielding rate of 17 μmol·h-1, which is significantly higher than that of pristine CN. The key intermediates engaged in CO2 photoreduction reaction are determined by the in situ diffuse reflectance infrared Fourier transform spectroscopy, which sponsors the construction of the possible photocatalytic CO2 reduction mechanism on the ACN nanosheets.

DOI: 10.1016/j.cjsc.2024.100245

Source: http://cjsc.ac.cn/cms/issues/564