One-Pot Synthesis of Ag@TiO2 Core−Shell Nanoparticles and Their Layer-by-Layer Assembly

Silver nanoparticles coated with a uniform, thin shell of titanium dioxide are synthesized via a remarkably simple one-pot route, where the reduction of Ag+ to Ag0 and the controlled polymerization of TiO2 on the surface of silver crystallites take place simultaneously. The prepared dispersions of coated nanoparticles display a surface plasmon band, which is significantly red-shifted with respect to that of bare Ag. High-quality ultrathin films of the core−shell clusters are prepared via layer-by-layer assembly. The nanoparticles are arranged in closely packed layers interlaced with polyelectrolyte producing a stratified core−shell hybrid material with unique structure and catalytic and electron-transport properties.