Chen Jing, Yang Minghua, Zhang Hongjiao, Chen Yuxin, Ji Yujie, Yu Ruohan, Liu Zhenguo
Key Laboratory of Flexible Electronics of Zhejiang Province, Ningbo Institute of Northwestern Polytechnical University, Ningbo 315103, China.
Department of Chemical and Material Engineering, Quzhou College of Technology, Quzhou 324002, China.
Molecules. 2024 Aug 13;29(16):3836. doi: 10.3390/molecules29163836.
Molecular oxygen activation often suffers from high energy consumption and low efficiency. Developing eco-friendly and effective photocatalysts remains a key challenge for advancing green molecular oxygen activation. Herein, graphitic carbon nitride (g-CN) with abundant hydroxyl groups (HCN) was synthesized to investigate the relationship between these polar groups and molecular oxygen activation. The advantage of the hydroxyl group modification of g-CN included narrower interlayer distances, a larger specific surface area and improved hydrophilicity. Various photoelectronic measurements revealed that the introduced hydroxyl groups reduced the charge transfer resistance of HCN, resulting in accelerated charge separation and migration kinetics. Therefore, the optimal HCN-90 showed the highest activity for Rhodamine B photodegradation with a reaction time of 30 min and an apparent rate constant of 0.125 min, surpassing most other g-CN composites. This enhanced activity was attributed to the adjusted band structure achieved through polar functional group modification. The modification of polar functional groups could alter the energy band structure of photocatalysts, narrow band gap, enhance visible-light absorption, and improve photogenerated carrier separation efficiency. This work highlights the significant potential of polar functional groups in tuning the structure of g-CN to enhance efficient molecular oxygen activation.
分子氧活化常常面临高能耗和低效率的问题。开发环保且高效的光催化剂仍然是推进绿色分子氧活化的关键挑战。在此，合成了具有丰富羟基的石墨相氮化碳（g-CN，即HCN），以研究这些极性基团与分子氧活化之间的关系。g-CN羟基修饰的优势包括更窄的层间距、更大的比表面积以及改善的亲水性。各种光电子测量表明，引入的羟基降低了HCN的电荷转移电阻，从而加速了电荷分离和迁移动力学。因此，最优的HCN-90在30分钟的反应时间内对罗丹明B光降解表现出最高活性，表观速率常数为0.125 min⁻¹，超过了大多数其他g-CN复合材料。这种增强的活性归因于通过极性官能团修饰实现的能带结构调整。极性官能团的修饰可以改变光催化剂的能带结构，缩小带隙，增强可见光吸收，并提高光生载流子分离效率。这项工作突出了极性官能团在调节g-CN结构以增强高效分子氧活化方面的巨大潜力。
