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

Abstract

Graphitic carbon nitride (g-C3N4) is a visible light-responsive photocatalytic material with important application prospects in many fields. However, the interaction between g-C3N4 monolayers makes it easy to aggregate and precipitate in aqueous solutions, and it is necessary to prepare stable g-C3N4 aqueous dispersions for their applications. Here we propose a facile, green, and low-cost method for the preparation of stable g-C3N4 dispersions by ultrasonicating g-C3N4 in lysozyme (LYZ) solution. The LYZ was adsorbed on the surface of g-C3N4 through non-covalent interactions such as electrostatic interaction, hydrogen bonding and π-cation interaction to prevent the aggregation of g-C3N4 nanolayers. The LYZ/g-C3N4 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-C3N4 and exhibited promising application prospects in the field of biomedicine and water disinfection.

Emerging Roles of Graphitic Carbon Nitride-based Materials in Biomedical Applications

“…The synthetic precursor materials of g-C 3 N 4 are usually metal-free, oxygen-free, and nitrogen-rich compounds, such as cyanamide − and guanidine hydrochloride. − The synthesis of g-C 3 N 4 is typically divided into two categories: “top-down” and “bottom-up” (Table ). The “top-down” process involves the reduction of large blocks into smaller particles and nanosheets through techniques such as chemical exfoliation, − microwave exfoliation, − ultrasonic exfoliation, − and template-assisted. − For example, g-C 3 N 4 nanosheets modified by different surface groups can be obtained by chemical exfoliation of bulk g-C 3 N 4 with different solutions . 3D g-C 3 N 4 with high porosity can be synthesized by g-C 3 N 4 prepared with a NaCl template .…”

Nanophase-photocatalysis: loading, storing, and release of H2O2 using graphitic carbon nitride

“…2,3 Here, we explore the potential of g-C 3 N 4 for the formation, storage, and release of hydrogen peroxide (H 2 O 2 ). The photocatalytic formation of H 2 O 2 has been widely reported 4 and is useful to disinfect, 5 bleach, 6 or clean environments. 7 In addition to effective production of H 2 O 2 based on photo-catalysis 8 from ambient oxygen and a hole quencher, there are reports of piezo-catalysis, 9 which is indicative of a broader range of molecular activation processes for g-C 3 N 4 at the microscopic scale.…”