Rapid Synthesis via Green Route of Plasmonic Protein-Coated Silver/Silver Chloride Nanoparticles with Controlled Contents of Metallic Silver and Application for Dye Remediation

The use of proteins for surface modifications of hybrid silver nanoparticles (NPs) is still poorly explored. In this study, we report a rapid green route synthesis of plasmonic protein-coated silver/silver chloride NPs (Ag/AgCl NPs) with controlled contents of metallic Ag (Ag0) using a modified photo-irradiation method. The contents of Ag0 were easily controlled varying the proportion between Ag+ and Cl− in the syntheses reactions. Interestingly, the Ag0 content in the protein-coated Ag/AgCl NPs increased with increasing of Cl− concentration. The synthesized plasmonic protein-coated Ag/AgCl NPs exhibited significant photocatalytic activity in the reduction of methylene blue dye under light irradiation due to the synergy between the metallic plasmonic effect and the semiconducting AgCl. However, a significant decrease in the content of semiconducting AgCl resulted in an undesirable synergistic effect. In our green route syntheses, all the properties of Ag/AgCl NPs were maintained with the addition of the advantages of the protein layer, which facilitates the dye adsorption and could contribute, along with Ag0, to reduce the electron–hole pairs recombination rate. Thus, with a simple and fast synthesis strategy these organic–inorganic hybrid NPs have the potential for applications for environmental remediation.