Preparation of noble metal nanoparticles @ titania precursor composite electrostatic self-assembled film

Noble metal nanoparticles as Au, Pd, and Pt were successfully incorporated throughout titania precursor composite layer-by-layer electrostatic self-assembled (LbL-ESA) film under basic condition because the LbL-ESA film is rich in 'free' imine groups, which can behave as ion-adsorption sites to the anionic precursors. The precursors were bound to the imine groups, resulting in formation of nanoparticles in the film through reduction. In case of Au composites, repetition of ion exchange-reduction treatment led to increase of the concentration of Au loaded and growth of these crystal sizes. The subsequent formation of nano particles at LbL-ESA film was convenient process to fabricate nanocomposites, and has a wide range of applications in the fields of catalysis, optoelectronics, and sensing materials.