Surface modification of titanium dioxide with silver nanoparticles for application in photocatalysis

Abstract

Silver nanoparticles (Ag NPs) have been deposited on powder TiO2 by a novel one-step method involving atmospheric pressure discharge cold plasma treatment without the use of any environmentally and biologically hazardous reducing agents. It was found that composite TiO2/AgNPs has structure like the core–shell constructed by the TiO2 sphere cores and Ag nanoparticles (NPs) shell, were obtained via Ag nanoseed mediated plasma chemical reduction. The prepared samples are characterized by using scanning electron microscopy, UV/Vis spectroscopy. The characterization results indicate that Ag NPs with an average size of about 10–25 nm are uniformly distributed on the surface of the Ag nanoseed modified TiO2 spheres. The effect of various operation parameters such as irradiation time, initial dye concentration and catalyst dose was studied. The results indicated that the catalytic efficiency of TiO2/Ag is higher than that of pure TiO2 and TiO2/Ag+ composites. The degradation of MB decreased from 78.0 to 37.0% during 20 min irradiation with the rise in startup MB concentration from 1.25 to 10 mg/L. An enhanced degradation of MB was noticed with the increment in the amount of composite from 1.2 to 2.4 g/L and afterwards an increase in catalyst mass to 7.2 g/L resulted decrease in the degradation of MB.