Reduction of Silver Ions Using an Alkaline Cellulose Dope: Straightforward Access to Ag/ZnO Decorated Cellulose Nanocomposite Film with Enhanced Antibacterial Activities

This work proposed a straightforward and sustainable strategy to synthesize a Ag/ZnO decorated cellulose nanocomposite. First, zincate was introduced into an aqueous cellulose-NaOH/urea dope to enhance the solution stability. Second, AgNO3 was directly added into the cellulose dope without gelation, and then was reduced into Ag NPs by cellulose chain. Finally, zincate transformed into ZnO via biomimetic mineralization along with the regeneration of the cellulose dope, and an Ag/ZnO decorated cellulose nanocomposite film was synthesized. The Ag NPs with a mean diameter of 16.5 nm were well dispersed in the cellulose matrix, and some were doped on the surface of the embedded ZnO crystal. With increase of the Ag loading, the nanocomposite film showed more rapid sterilization for Escherichia coli than Staphylococcus aureus, and complete eradication could be achieved within 3 h for both bacteria. This simple and environmental friendly method hopefully provided new routes for large-scale production of antibacterial cellulose-based nanohybrids in industry.