School of Chemistry and Chemical Engineering, Southeast University, No. 2 Dongnandaxue Road, Nanjing 211189, Jiangsu, PR China.
School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, No. 2 Mengxi Road, Zhenjiang 212003, Jiangsu, PR China.
J Hazard Mater. 2021 Jul 5;413:125376. doi: 10.1016/j.jhazmat.2021.125376. Epub 2021 Feb 10.
Graphitic carbon nitride is considered as one of the promising photocatalysts for pollution elimination from wastewater. Manipulating the microstructure of carbon nitride remains a challengeable task, which is essential for improving light absorption, separating photogenerated carrier and creating reactive sites. Herein, a carbon vacancy modified hierarchical carbon nitride microrod (CN1.5) has been prepared templated from a melamine-NHOH·HCl complex. The hierarchical microrods are demonstrated to be comprised of interconnected nanosheets with rich carbon vacancies, which endows it with high specific surface area, enhanced light utilization efficiency, available reactive sites, improved charge carrier separation and numerous mass-transport channels. The resultant photocatalyst CN1.5 exhibits an excellent photodegradation efficiency of 87.9% towards tetracycline under visible light irradiation. The remarkable apparent rate constant of 4.91 × 10 min is 7.3 times higher than that of bulk CN. In addition, the degradation pathways are deduced base on the observation of degradation intermediates generating in the photocatalytic process. Mechanism investigation indicates that the major contribution for photodegradation is attributed to ·O, O and HO species. This work provides new insights into advancing carbon nitride's microstructure to improve photocatalytic degradation performance for highly efficient antibiotic removal and environment remediation.
石墨相氮化碳被认为是一种很有前途的用于消除废水中污染物的光催化剂。然而，调控氮化碳的微观结构仍然是一个具有挑战性的任务，因为这对于提高光吸收、分离光生载流子和创造反应活性位是至关重要的。在此，我们通过三聚氰胺-NHOH·HCl 复合物模板制备了一种具有碳空位的分级氮化碳微棒（CN1.5）。研究表明，分级微棒由具有丰富碳空位的相互连接的纳米片组成，这赋予了其高比表面积、增强的光利用效率、可用的反应活性位、提高的载流子分离效率和众多的质量传输通道。所得的光催化剂 CN1.5 在可见光照射下对四环素具有优异的光降解效率（87.9%）。其明显的表观速率常数为 4.91×10-2 min-1，是块状 CN 的 7.3 倍。此外，根据光催化过程中生成的降解中间产物的观察，推导出了降解途径。机理研究表明，光降解的主要贡献归因于·O2-、O2-和 HO 等活性物种。这项工作为推进氮化碳的微观结构提供了新的见解，以提高光催化降解性能，从而实现高效去除抗生素和环境修复。
