Synthesis and characterization of silver nanoparticle-modified TiO2 powder: photocatalytic properties and antibacterial activity.

The surface of the commercial TiO2 (P25) has been modified with Argentum using two different approaches. In the first case silver nanoparticle, synthesized previously by "green" method with aqueous grape pomace extract, were used. The second modified sample was obtained by Argentum nitrate impregnation. The component profile of the grape pomace extract has been analyzed by liquid chromatography mass spectrometry (LC–MS). The peak absorbance of the UV–vis spectra at 400 nm confirmed the formation of silver nanoparticles. The modified TiO2 powders with AgNPs were characterized by X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM), their photocatalytic properties and antibacterial activity were studied. SEM analysis showed that modified samples are presented by small spherical nanoparticles with a size ranged from 9 to 13 nm. The EDS analysis displayed intense signals of the silver element. The results of the antibacterial activity studies showed that TiO2 modified using green approach possesses higher antibacterial activity against Gram-negative bacteria in comparison with TiO2 modified by impregnation method. [ABSTRACT FROM AUTHOR]