Buildup of Composite Films Containing TiO₂/PbS Nanoparticles and Polyelectrolytes Based on Electrostatic Interaction

Preparation methods for TiO 2 /PbS “coupled” type nanoparticles are described, in which PbS is formed in - situ on the surface of TiO 2 . FTIR was used to follow the preparation process and UV−vis spectra confirmed the stabilizing effect of TiO 2 on the formation of PbS nanoparticles. This “coupled” type of nanoparticle was further assembled into ultrathin composite films based on electrostatic interaction as the driving force. Various methods, including UV−vis, IR, EDS, TEM, AFM, and XPS, identified the coexistence of two kinds of nanoparticles in ultrathin composite films. Photocurrent measurements indicated that efficient charge transfer occurred in the composite films.