Alkane Chain-Bearing Pyridylboronic Acid-Grafted Graphitic Carbon Nitride-Loaded Polyacrylonitrile Membrane for Efficient Photocatalytic Bacterial Killing.

Abstract

A positively charged ammonium side chain, a pyridylboronic acid side chain, and mixed two moieties were grafted on intrinsic g-C₃N₄ to yield functionalized materials, g-C₃N₄-C₄, g-C₃N₄-B, and g-C₃N₄-C₄-B. All the decorated g-C₃N₄ materials displayed enhanced photocatalytic ROS (¹O₂ and ^•O₂^-) generation capabilities compared to intrinsic g-C₃N₄. Among them, g-C₃N₄-B displayed the most potent ROS generation capability. In addition, ξ potential results revealed the strongest affinity of g-C₃N₄-C₄-B toward representative Gram-negative and positive bacteria (MDR Acinetobacter baumannii and Staphylococcus aureus). The photocatalytic antibacterial results demonstrated that g-C₃N₄-B could achieve faster and efficient bacterial killing compared with g-C₃N₄-C₄ and g-C₃N₄-C₄-B (>99% killing rates toward MDR A. baumannii and S. aureus and >95% toward Escherichia coli). Thus, it could be concluded that ROS generation capability plays a more important role in photocatalytic antibacterial activity over bacterial binding capability in the current case. g-C₃N₄-B was further fabricated into a PAN fiber membrane for photocatalytic antibacterial application. The 0.8 wt % g-C₃N₄-B-loaded PAN membrane showed potent antibacterial activities toward MDR A. baumannii, S. aureus, and E. coli, with efficiencies of 99.79%, 99.37%, and 99.96%, respectively. Thus, g-C₃N₄-B could serve as a potent broad-spectrum photocatalytic antibacterial material. And we proposed a novel strategy for improving photocatalytic antibacterial activity for g-C₃N₄.