Zhang Qiang, Chen Juan, Che Huinan, Liu Bin, Ao Yanhui
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, No.1, Xikang road, Nanjing, 210098, China.
Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong SAR, 999077, China.
Small. 2023 Oct;19(42):e2302510. doi: 10.1002/smll.202302510. Epub 2023 Jun 15.
Stimulating electron transitions and promoting exciton dissociation are crucial for improving the photocatalytic performance of polymeric carbon nitride (CN) yet still challenging. Herein, a novel CN with C dopant and asymmetric structure (CC-UCN ) is ingeniously synthesized. The obtained CC-UCN not only reinforces the intrinsic π→π* electron transitions, but also successfully awakens additional n→π* electron transitions. Besides, charge centers dislocation caused by symmetry breaking induces a spontaneous polarized electric field, effectively breaking the constraints of Coulomb electrostatic interaction between electrons and holes and driving their directional migration. Along with the spatial separation of reduction and oxidation sites, CC-UCN shows exceptional O activation and holes oxidation efficiency, thus exhibits a high degradation rate constant (0.201 min ) and mineralization rate (80.1%) for bisphenol A (BPA)(far outperforming pristine and other modified CNs). This work proposes a novel perspective for developing high-efficiency photocatalysts and comprehending the underlying mechanism of O activation and holes oxidation for pollutant degradation.
激发电子跃迁和促进激子解离对于提高聚合氮化碳（CN）的光催化性能至关重要，但仍具有挑战性。在此，巧妙地合成了一种具有C掺杂和不对称结构的新型CN（CC-UCN）。所获得的CC-UCN不仅增强了固有的π→π电子跃迁，还成功地激发了额外的n→π电子跃迁。此外，由对称性破缺引起的电荷中心位错会诱导自发极化电场，有效地打破电子与空穴之间库仑静电相互作用的限制，并驱动它们的定向迁移。随着还原和氧化位点的空间分离，CC-UCN表现出优异的O活化和空穴氧化效率，因此对双酚A（BPA）显示出高降解速率常数（0.201 min⁻¹）和矿化率（80.1%）（远远优于原始的和其他改性的CN）。这项工作为开发高效光催化剂以及理解O活化和空穴氧化用于污染物降解的潜在机制提出了新的视角。
