Electrochemical formation and properties of polymethylolacrylamide film with inclusion of platinum particles

Abstract

The possibility of single-stage formation of a polymethylolacrylamide/Pt composite by the electropolymerization technique is studied. The optimum process parameters are determined. It is found that addition of chloroplatinic acid (H2PtCl6 · 6H2O) to the monomer composition results in partial inhibition of electropolymerization and a drastic decrease in the rate of polymer film formation on a stainless steel cathode in the mode of potentiostatic electrolysis. It is found that addition of chitosan to electrolyte intensifies inclusion of Pt into the polymer matrix through formation of its complex with H2PtCl6 · 6H2O, as confirmed by NMR studies. The time of formation of the complex does not exceed 30–60 min. Reduction of the complex results in simultaneous formation of platinum nanoparticles in the polymer matrix and in their stabilization by the insoluble chitosan phase. The content of platinum in the composite grows at an increase in the concentration of H2PtCl6 · 6H2O and reaches 25.15 at %. The regularities of polymer deposit distribution over the metal surface, morphology, particle size, and elemental composition of composites was studied using impedance spectroscopy, X-ray phase analysis, and scanning field–emission electron microscopy. The method of cyclic voltammetry was used to establish the electrochemical properties of metal/polymer composite films. It is shown that polymer methylolacrylamide films modified by chitosan and platinum manifest electrocatalytic activity with respect of oxidation of ethanol.