Lysozyme-assisted ultrasonic exfoliation of graphitic carbon nitride into highly stable nanosheets with enhanced bactericidal capacity

Abstract Graphitic carbon nitride (g-C 3 N 4 ) is a visible light-responsive photocatalytic material with important application prospects in many fields. However, the interaction between g-C 3 N 4 monolayers makes it easy to aggregate and precipitate in aqueous solutions, and it is necessary to prepare stable g-C 3 N 4 aqueous dispersions for their applications. Here we propose a facile, green, and low-cost method for the preparation of stable g-C 3 N 4 dispersions by ultrasonicating g-C 3 N 4 in lysozyme (LYZ) solution. The LYZ was adsorbed on the surface of g-C 3 N 4 through non-covalent interactions such as electrostatic interaction, hydrogen bonding and π-cation interaction to prevent the aggregation of g-C 3 N 4 nanolayers. The LYZ/g-C 3 N 4 could quickly re-form a uniform aqueous dispersion solution after freeze-drying, and exhibit good stability. Further, the results of photocatalytic sterilization showed that the assisted dispersion of LYZ enhanced the bactericidal activity of g-C 3 N 4 and exhibited promising application prospects in the field of biomedicine and water disinfection.