Synthesis of the composites of graphene nanoplatelets/(Ni-Co) and their properties

On the base of graphene/metal type systems there are high-content capacitors, electrodic and magnetic materials of different applications are created with use of nickel, cobalt, and iron. The catalytic activity of systems with bimetal inclusions was studied, moreover the special synergies of the properties of bimetallic particles and fundamental difference between systems containing individual metals were highlighted. The system GNP/(Ni-Co) was synthesized by co-precipitation from a solution of hydrazine-hydrate. The presence of phase GNP, nickel, cobalt was shown by method of X-ray diffraction analysis of crystallites of the size of 15÷20 nm. The image of transmission electron microscope shows that the size of metal particles is 20 nm, and that of their agglomerates in composite is 200 nm. The nanocomposites are sensitive to vapors of acetone, ammonia, ethyl alcohol. The process of adsorption in acetone and ammonia vapors happens with the irreversible loss of properties, which is due to the oxidation of metals on the GNP surface. Sensory properties of composites GNP/(Ni-Co) are stable over many cycles using ethanol vapors. The electrophysical studies indicate a significant difference between the properties at low frequencies of Ni-Co and GNP/(Ni-Co). In the area of ultra-high frequency the characteristics have similar values, which are due to the relaxation phenomena. The resulting nanocomposites can be promising for use in energy conversion devices, catalysis, gas sensor, screening, and magnetic devices.