Two-dimensional photochemical synthesis of plate-like nanoparticles

The method of two-dimensional (2-D) synthesis of nanoparticles is developed in which true 2-D diffusion of precursor molecules, active intermediates, nucleus, nanoparticles, surfactants and additives occurs only in the plain of Langmuir monolayer at the gas/liquid interface. In the present work, nanoparticles were generated by the ultraviolet (UV) decomposition of iron pentacarbonyl, a volatile water-insoluble compound, in a mixed monolayer with SA on the aqueous phase surface. Nanoparticles were formed in a gaseous phase of a monolayer (at very low or no surface pressure). The morphology of nanoparticles, structure and composition of nanoparticulate Langmuir–Blodgett films were characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), Fourier transform-infrared (FT-IR) spectroscopy and X-ray diffraction (XRD). The size and morphology of nanoparticles is dependent substantially on the monolayer state under the synthesis process. Controlling the mixed monolayer content and compression state opens wide possibilities for regulation of the nanoparticles growth processes to obtain inorganic nanostructures with various and unique morphologies. We demonstrate that 2-D monolayer synthesis at the gas/liquid interface allows to produce anisotropic extremely flat metal-containing nanoparticles with very high surface to volume ratio what can be perspective for catalysis, optical and other applications.