Preparation of g-C3N4/CQDs/Ag2S Composite Material and Its Antibacterial Properties

The emergence of bacterial resistance to traditional antibiotics and its global spread has brought huge threats to human life and health, and the need for new alternative antibacterial agents has become increasingly urgent. The rapid development of nanoscience provides a potential alternative to antibacterial therapy. In this study, g-C3N4 was synthesized using melamine as the raw material. It was then successfully combined with carbon quantum dots (CQDs) and silver sulfide to synthesize a g-C3N4/CQDs/Ag2S composite material. Such combination narrows the band gap of g-C3N4 from 2.53 eV to 2.21 eV and enhances the photocatalytic efficiency. Consequently, it indicated photocatalytic antimicrobial effects against three strands of bacteria, Shylococcus aureus (Grampositive), Escherichia coli (Gram-negative) and Methicillin-resistant Staphylococcus aureus under the irradiation of visible light. Other than the common pathogens, g-C3N4/CQDs/Ag2S exhibited an appreciable inhibition against the well-known drug-resistant bacteria. With its antimicrobial features and excellent photoelectric properties, the as prepared nanocomposites show its potential in the development of new antimicrobial and photocatalytic materials.