Proton-Functionalized Graphitic Carbon Nitride for Efficient Metal-Free Disinfection of Escherichia Coli under Low-Power Light Irradiation.

Universal access to clean water has been the global ambition over the years. Photocatalytic water disinfection via advanced oxidation processes has been regarded as one of the promising methods in breaking down microbials. The forefront of this research focuses on the application of metal-free photocatalysts for disinfection to prevent secondary pollution. Graphitic carbon nitride (g-C3N4) has achieved instant notoriety as a metal-free and visible-light-responsive photocatalyst for various energy and environmental applications. However, the efficiency of g-C3N4 in photocatalysis is still affected by its rapid charge recombination and sluggish electron transfer kinetics. In this contribution, two-dimensional protonated g-C3N4 was employed as metal-free photocatalyst for water treatment and demonstrated 100% disinfection of Escherichia coli within 4 h under 23 W light bulb irradiation. The introduction of protonation can modulate the surface charge of g-C3N4 which enhance its conductivity and provide a "highway" for the delocalization of electrons. This work highlights the potential of conjugated polymer in antibacterial application.