Engineering Atomic Ag<sub>1</sub>–N<sub>6</sub> Sites with Enhanced Performance of Eradication Drug-Resistant Bacteria over Visible-Light-Driven Antibacterial Membrane
Shaosheng Rao, Zhongti Sun, Qinqin Liu, Chao Cheng, Cheng Jin, Jinsong Gao, Bing Li, Yi Li, Lei Liu, Juan Yang, Yongfa Zhu
Abstract
Utilizing visible light for water disinfection is a more convenient, safe, and practical alternative to ultraviolet-light sterilization. Herein, we developed silver (Ag) single-atom anchored g-C 3 N 4 (P-CN) nanosheets (Ag 1 /CN) and then utilized a spin-coating method to fabricate the Ag 1 /CN-based-membrane for effective antibacterial performance in natural water and domestic wastewater. The incorporated Ag single atom formed a Ag 1 –N 6 motif, which increased the charge density around the N atoms, resulting in a built-in electric field ∼17.2 times stronger than that of pure P-CN and optimizing the dynamics of reactive oxygen species (ROS) production. Additionally, the Ag 1 –N 6 motif inhibited the release of Ag ions, ensuring good biocompatibility. Based on the first-principles calculation, the adsorption energy of O 2 on the Ag 1 /CN (−0.32 eV) was lower than that of P-CN (−0.07 eV), indicating that loaded Ag single atom can lower the energy barrier for O 2 activation, generating extra *OH radicals that cooperated with *O 2 – to effectively neutralize bacteria. As a result, the Ag 1 /CN powder-catalyst with the concentration of 30 ppm demonstrated a 99.9% antibacterial efficiency against drug-resistant bacteria ( Escherichia coli, Staphylococcus aureus, kanamycin-resistant Escherichia coli, and methicillin-resistant Staphylococcus aureus ) under visible-light irradiation for 4 h. This efficacy was 24.8 times higher than that of the P-CN powder catalyst. Moreover, the Ag 1 /CN-based-membrane can maintain a 99.9% bactericidal efficiency for natural water and domestic wastewater treatment using a homemade flow device, demonstrating its potential for water disinfection. Notably, the visible-light-driven antibacterial efficiency of the Ag 1 /CN catalyst outperformed the majority of the reported g-C 3 N 4 -based catalysts/membranes.