Preparation And Electrocatalytic Property Of Multilayer Films Constructed From Polyoxometalate And Poly(Amidoamine)

The studies on organic-inorganic composite films have drawn more and more attention owing to their potential applications in luminescence,photochromism,magnetism,electrics and catalysis.Organic-inorganic composite film materials with optical,electrical,and magnetic properties are one of the research focuses in contemporary materials science.This paper places emphasis on the preparation of polyoxometalate-based organic-inorganic composite films and their electrocatalysis properties.The ordered and stable organic-inorganic composite films constructed from transitional-metal-substituted polyoxometallates and polyamidoamine dendrimers are prepared by the layer-by-layer self-assembly technique.The differences between soaking and cyclic voltammetry scanning method for film preparation are also discussed.The multilayer film including Pt nanoparticles is prepared by cyclic voltammetry scanning method.The composition,structure,and properties of the as prepared composite films have been characterized by UV-vis,X-ray photoelectron spectra,atomic force microscopy and cyclic voltammetry.These measurements and analysis showed that the above-mentioned inorganic-organic components were incorporated into the composite films and their original structures and properties remained in the films.The growth processes of the assembled films were quantitative and highly reproducible from layer to layer.The surfaces were smooth and were dispersed with uniform spherical particles.The films constructed from [PMo₁₁VO₄₀]^4-,[PCu（H₂O）Mo₁₁O₃₉]^5-,[PW₁₁O₃₉Pd（H₂O）]^5- and PAMAM are stable and exhibit an excellent electrocatalytic activity to the reduction of NO₂^-,BrO₃^-,H₂O₂ and the oxidation of ascorbic acid.With increasing the layer numbers,the catalytic activity is enhanced.The multilayer film including Pt nanoparticle shows good electrocatalytic activity for the oxidation of methanol and poison resistance ability.