Abstract Improving the efficiency of Ag nanoparticles (NPs) in an antibacterial system remains a problem to be solved. Herein, a simple polyethyleneimine (PEI) modification strategy has been developed for realizing the high dispersion of Ag NPs with average size of 10 nm over two dimensional nanosheets of g-C3N4 photocatalyst, and the as-prepared ternary Ag/PEI/CN hybrid demonstrates enhanced bifunctional performance of antibiotics (e.g., tetracycline, TC) degradation and antibacterial activity. The enhanced mechanism is investigated and proposed to be a synergy effect between reactive oxygen-containing species (ROS, e.g., •OH and O2•−) derived from PEI modified g-C3N4 photocatalyst and slow released Ag+ ions generated by the highly dispersed Ag NPs as antimicrobial agent. Furthermore, the surface plasmonic effect of Ag NPs and coupling of PEI can increase light absorption and accelerate the electron-hole separation and mobility. Consequently, more availability of ROS along with holes and Ag+ ions can accelerate the death of bacteria via destructing biomolecules. As a result, under visible-light irradiation, Ag/PEI/CN hybrid presents greatly improved antibacterial activity against E. coli, including a low MIC100% of 30 ppm and MBC97% of 10 ppm and enhanced photocatalytic performance towards TC degradation (∼80 % TC can be degraded within 60 min).

中文翻译：

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聚乙烯亚胺在 g-C3N4 纳米片上诱导高度分散的银纳米粒子以实现高效的光催化和抗菌性能

摘要 提高抗菌系统中银纳米粒子 (NPs) 的效率仍然是一个有待解决的问题。在此，开发了一种简单的聚乙烯亚胺 (PEI) 改性策略，用于实现平均尺寸为 10 nm 的 Ag NPs 在 g-C3N4 光催化剂的二维纳米片上的高分散，所制备的三元 Ag/PEI/CN 杂化物证明增强抗生素（如四环素、TC）降解和抗菌活性的双功能性能。增强的机制被研究并提出是源自 PEI 修饰的 g-C3N4 光催化剂的活性含氧物质（ROS，例如，•OH 和 O2•-）与由高度分散的 Ag NPs 产生的缓慢释放的 Ag+ 离子之间的协同效应作为抗菌剂。此外，Ag NPs 的表面等离子体效应和 PEI 的耦合可以增加光吸收并加速电子 - 空穴的分离和迁移。因此，更多的活性氧以及空穴和银离子可以通过破坏生物分子加速细菌的死亡。因此，在可见光照射下，Ag/PEI/CN 杂化物对大肠杆菌的抗菌活性大大提高，包括 30 ppm 的低 MIC100% 和 10 ppm 的 MBC97% 以及增强的光催化降解 TC 性能（~80 % TC 可在 60 分钟内降解）。