摘要：A series of Ag@TiO2 catalysts with core-shell structure were successfully synthesized by a sol-gel method. The samples were prepared by a sol-gel method using silver nitrate, hydrazine, cetyltrimethylammonium bromide and titanium tetra-isopropoxide as the starting materials. The catalysts were characterized by ICP-MS, XRD, TEM, HRTEM and XPS. The results indicated that the silver core was in metallic state and the TiO2 shell was in anatase state. The size of Ag nanoparticles in core was about 5 and 10 nm, and the shell size of titanium dioxide was 10 and 20 nm. The core was single crystalline Ag nanoparticle and the shell was made up of many TiO2 nanoparticles. The photocatalytic activity of Ag@TiO2 was much higher than that of bare TiO2. Large amounts of hydroxyl groups were present on the surface of TiO2. The catalysts which were treated by hydrothermal method had the higher lattice oxide percentage and higher photocatalytic activities. The core-shell structure can prevent Ag from aggregation.
