Plasmon enhanced photocatalytic and antimicrobial activities of Ag-TiO2 nanocomposites under visible light irradiation prepared by DBD cold plasma treatment.

Silver nanoparticles (Ag NPs) have been deposited on powder P25 by a novel two-step method involving a precipitation reaction and atmospheric pressure dielectric barrier discharge (DBD) cold plasma treatment without the use of any environmentally and biologically hazardous reducing agents. The silver precursor is formed in the processing of precipitation reaction and then completely reduced to the metallic state by atmospheric pressure DBD cold plasma treatment as proved by X-ray photoelectron spectroscopy, UV-Visible absorption spectra and HRTEM analyses. TEM images indicate that the Ag NPs with average diameter of 3.7 nm were deposited on powder P25 with high dispersion although no reducing agents, stabilizers or surfactants were used. The prepared products show remarkable improvement for methylene blue (MB) photodegradation and effective inhibition of bacterias against Escherichia coli and Staphylococcus aureus.