Environmentally Sustainable Fabrication of Ag@<i>g‑</i>C₃N₄ Nanostructures and Their Multifunctional Efficacy as Antibacterial Agents and Photocatalysts

Abstract

Noble-metal silver (Ag) nanoparticles (NPs) anchored/decorated onto polymeric graphitic carbon nitride (<i>g</i>-C₃N₄) as nanostructures (NSs) were prepared using modest and environment-friendly synthesis method with a developed-single-strain biofilm as a reducing implement. The as-fabricated NSs were characterized using standard characterization techniques. The nanosized and uniform AgNPs were well deposited onto the sheet-like matrix of <i>g</i>-C₃N₄ and exhibited good antimicrobial activity and superior photodegradation of dyes methylene blue (MB) and rhodamine B (RhB) dyes under visible-light illumination. The Ag@<i>g</i>-C₃N₄ NSs exhibited active and effective bactericidal performance and a survival test in counter to <i>Escherichia coli</i>, <i>Staphylococcus aureus</i>, and <i>Pseudomonas aeruginosa.</i> The as-fabricated NSs also exhibited superior visible-light photodegradation of MB and RhB in much less time as compared to other reports. Ag@<i>g</i>-C₃N₄ NSs (3 mM) showed superior photocatalytic measurements under visible-light irradiation: ∼100% MB degradation and ∼89% of RhB degradation in 210 and 250 min, respectively. The obtained results indicate that the AgNPs were well deposited onto the <i>g</i>-C₃N₄ structure, which decreases the charge recombination rate of photogenerated electrons and holes and extends the performance of pure <i>g</i>-C₃N₄ under visible light. In conclusion, the as-fabricated Ag@<i>g</i>-C₃N₄ NSs are keen nanostructured materials that can be applied as antimicrobial materials and visible-light-induced photocatalysts