BUILDUP OF COMPOSITE FILMS CONTAINING TIO2 PBS NANOPARTICLES AND POLYELECTROLYTES BASED ON ELECTROSTATIC INTERACTION/

Preparation methods for TiO2/PbS ''coupled'' type nanoparticles are de scribed, in which PbS is formed in-situ on the surface of TiO2. FTIR w as used to follow the preparation process and UV-vis spectra confirmed the stabilizing effect of TiO2 on the formation of PbS nanoparticles. This ''coupled'' type of nanoparticle was further assembled into ultr athin composite films based on electrostatic interaction as the drivin g force. Various methods, including UV-vis, IR, EDS, TEM, AFM, and XBS , identified the coexistence of two kinds of nanoparticles in ultrathi n composite films. Photocurrent measurements indicated that efficient charge transfer occurred in the composite films.