Synthesis of silver nanoparticles and its applications in photocatalysis

Different morphologies of uniform silver nanoparticles have been synthesized in large quantities by reducing silver nitrate(AgNO3) with ethanol and/or water in the presence of poly(vinylpyrrolidone)(PVP).The effects of the proportion of ethanol to water,the concentration of AgNO3 and the reaction time on the shapes and sizes of silver nanoparticles have been studied.The obtained quasi-nanospheres,nanocubes and nanowires silver particles were characterized by XRD,SEM,TEM and UV-vis adsorption spectroscopy.In addition,the photocatalytic performance of the Ag/mesoporous titania was investigated by UV-light induced photocatalytic degradation of methyl orange.The results showed that both nanospherical(with the diameter distribution about 30-70nm) and nanocubic(the diameter about 80-140nm) Ag nanoparticles were found to significantly enhance the photocatalytic activity of mesoporous TiO2,and the smaller Ag particles exhibited the higher improved photocatalytic activity than the big ones.