Софія Федорченко

Vasyl Stefanyk Precarpathian National University · Department of Natural Sciences

Ultrafine NiFe2O4 (T0) and NiFe2O4 / rGO composites have been synthesized by solution combustion method. The presence of rGO in the composite (33 wt.% (T1) or 66 wt.% (T2)) causes a decrease in the average particle size of the oxide phase from 16 to 10-11 nm with their transition to superparamagnetic with a decrease in the mixed spinel inversion de...

A systematic study of the effect of various types of surfactants (polyethylene glycol, Trinon X-100 and cetyltrimethylammonium bromide) and subsequent annealing on the magnetic ordering and morphology of the nickel ferrite / reduced graphene oxide composite materials has been carried out. Hydrazine hydrate has been used both as an agent to initiate...

The electrochemical properties of MoO2/mesoporous carbon and MoO2/reduced graphene oxide (rGO) materials have been investigated. Composite materials have been obtained by ultrasound dispersion of hydrothermally synthesized MoO2 and carbon or rGO (mass ratio of 1:1 and 1:2). The samples have been tested using XRD, SEM, and low-temperature nitrogen a...

Cobalt–iron spinel/reduced graphene oxide composite material was obtained by one-step hydrothermal synthesis. XRD, low temperature nitrogen adsorption, Mossbauer spectroscopy, micro-Raman spectroscopy and cyclic voltammetry were used for materials characterization. The influence of the annealing temperature and graphene component presence on the pr...

In this work, the effect of annealing in the range of 200-500°C on the phase composition, morphological properties and magnetic microstructure of hydrothermally synthesized CuFe2O4 and CuFe2O4/reduced graphene oxide has been investigated using XRD, SEM, Mossbauer spectroscopy, and low-temperature nitrogen adsorption methods. The influence of the pr...

Ultrafine nickel ferrite and nickel ferrite/reduced graphene oxide nanocomposite materials have been synthesized by self-combustion method using glycine, citric acid and urea as chelating agent. The comparative analysis of structural and magnetic properties of the obtained materials in a temperature range of 300–900 °C has been performed. The chang...

The paper presents the experimental results of the composite-materials' synthesis on the base of nickel hydroxide b-Ni(OH) 2 and reduced graphene oxide using ultrasound dispersion of hydrothermally obtained b-Ni(OH)2 and previously chemically reduced graphene oxide. The synthesized material is investigated by XRD, SEM, and impedance spectroscopy. T...

The ultrafine iron hydroxide/oxide systems are fabricated by a hydrothermal approach, using iron nitrate and citric acid as precursors. The phase composition, crystal and magnetic microstructures, morphology, conductivity, and optical properties are characterized by X-ray diffraction, scanning electron microscope, impedance spectroscopy, Mössbauer...

The electrochemical performance of Ni(OH) 2 / reduced graphene oxide nanocomposite obtained by ultrasonic treatment of hydrothermal synthesized β-Ni(OH) 2 and rGO has been investigated in alkaline medium. The material demonstrates good specific capacitance and is quite cost effective. The kinetics of proton migration in electrode materials has be...

Nickel iron spinel/reduced graphene oxide composite material was synthesized by simultaneous hydrothermal treatment of nickel and ferric nitrates and graphene oxide colloidal solution obtained using Hummers method. XRD, SEM, Mossbauer spectroscopy, impedance spectroscopy and low temperature nitrogen adsorption were used for materials characterizati...

Structural and optical properties of β-Ni(OH)2/reduced graphene oxide nanocomposite which was obtained by ultrasound dispersion of hydrothermally synthesized β-Ni(OH)2 and reduced graphene oxide were investigated. Frequency dependencies of conductivity for initial components and composite materials were studied. Specific surface areas of reduced gr...

Mesoporous maghemite (γ-Fe2O3), obtained by thermal decomposition of iron citrate xerogel hydrate, was investigated by X-ray di raction, scanning electron microscopy, the M ssbauer and impedance spectroscopies and low temperature nitrogen adsorption. The influence of precursor molar concentration on the material morphology, crystalline and magnetic...

Ultrafine sol-gel synthesized iron oxy-hydroxides β-FeOOH was investigated by XRD, TEM, Mossbauer and impedance spectroscopies and low temperature nitrogen adsorption. The influence of precursor molar concentration on the material morphology, crystalline and magnetic microstructures was studied. The model of initial precursors (FeCl3·6H2O) molarity...

Nanodispersed rutile with rod-like particles is synthesized by hydrolysis of TiCl4 in hydrochloric acid - ethanol alcohol aqueous solution. It is found that the specific surface area, crystallite size and degree of agglomeration are determined by molar ratio of ethanol in reaction medium. According to HR-TEM images and XRD data rutile crystallites...

The phenomenological model of sulphate anions effect on the nanodispersed titania synthesis during hydrolysis of titanium tetrachloride was studied. It was proposed that both chelating and bridging bidentate complexes formation between sulphate anions and octahedrally coordinated [Ti(OH)h(OH2)6−h](4−h)+ mononers is the determinative factor for anat...

The photocatalytic properties of hydrothermally obtained anatase/brookite nanocomposite are studied. The influence of phase composition, structure, morphology, and optical characteristics of synthesized materials on their photocatalytic characteristics is investigated. Methylene blue and formaldehyde photooxidation reactions are analysed. The maxim...

The technology of recycling of polymer-coated paper waste is described. Physical and chemical properties of fibers obtained from wallpaper wastes and from their derivative compositions were investigated. A special crusher with primary and secondary grinding stages and with a section for separating paper fibers from polymer coating was designed. Ind...

У статті розглянуто вплив аміно- і гідроксилвмісних модифікаторів в умовах проведення реакції доконденсації та різних каталітичних систем реакції конденсації на зменшення токсичності карбамідоформальдегідних смол (КФС)