Synthesis of nanoparticle/ligand composite thin films by sequential ligand self assembly and surface complex reduction

Nanocomposite thin films consisting of ligand-connected metal nanoparticles were deposited by iteration of ligand assembly, surface complex formation and reduction. This novel and convenient approach combines characteristics of the layer-by-layer (LbL) and the successive ion layer adsorption and reaction (SILAR) techniques. In contrast to classical LbL assembly, the nanoparticle formation is performed in situ, avoiding separate reduction, protection and attachment steps. To demonstrate the versatility of the approach, different metal precursors (Pd, Ag and Au salts) and linkers (1,2-ethanedithiol, 1,4-benzenedithiol and polythiol) were applied. The formation of dithiol-linked nanoparticle films was confirmed by TEM and XPS. By combining the deposition protocol with ion track etched polycarbonate templates, nanotubes and nanowires with high aspect ratios of up to 300 could be fabricated.

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► Deposition of composite thin films by in situ nanoparticle formation on thiol layers.
► Method combines characteristics of LbL and SILAR depositions.
► Facile variation of metal and ligand gives access to films of flexible composition.
► Complex shaped substrates can be used, allowing the synthesis of composite nanotubes.