Fabrication of AgA u alloy-TiO2 core-shell nanoparticles and their photocatalytic properties

In this paper, for improving the photocatalytic efficiency of titania（TiO2） nanoparticles（NPs）, Ag Au alloy-TiO2 core-shell NPs are fabricated via a sol-gel（SG） process in the presence of Ag Au alloy NPs with block copolymer shells as templates. The photocatalytic activities of the Ag Au-TiO2 NPs on the photodecomposition of methylene blue（MB） are investigated. The Ag Au-TiO2 composite NPs coated with 5.0% titania related to block copolymers show higher photocatalytic activity than the other samples in which the titania contents are larger than 5.0%. The results indicate that the increase of the thickness of the TiO2 shell leads to the decrease of the photocatalytic activity.