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Mathematical model of the subdiffusion impedance in multilayer nanostructures is considered on the basis of the Cattaneo-type diffusion equation in fractional derivatives. The Nyquist diagrams are calculated for different values of subdiffusion coefficient and time parameter (time for which the flow delays concerning the gradient of charge carriers concentration). A qualitative agreement is obtained for the GaSe system with encapsulated β-cyclodextrin.

A novel flexible electrospun nanofiber/γ-Fe₂O₃ composite has been obtained from suspension of γ-Fe₂O₃ nanoparticles in polyvinylpyrolidone solution in dimethylformamide. The impedance spectroscopy of the synthesized nanofiber/γ-Fe₂O₃ composite was carried out. Negative magnetoresistance and giant magnetocapacitance effects, as well as phenomenon of a "negative capacitance" at room temperature were observed in magnetic field (2.75 κOe) in infra-low frequency range. The polarization properties and volt-ampere characteristics of the nanocomposite in the applied magnetic field indicate the increase in the dielectric permittivity ɛ and the emergence of spin electromotive force, which enables us to accumulate of electric energy at quantum level. A quantum-mechanical model, which explained the non-monotonous behaviour of the volt-ampere characteristic of the novel nanofiber based composite, has been suggested.

We have discovered a huge enhancement of the supercapacity (up to 4 times) under sun illumination of electrodes fabricated from cavitated nanoporous carbon being carbonized from an iodine doped β–cyclodexryn. This effect was achieved even without a frequently used KOH treatment and is caused by enhancement of effective activated surfaces. The synthesized cavitated nanoporous carbon exhibits principally different accumulative features at the carbon/electrolyte interface. Relationship between the porous structure, electronic properties of supramolecular nanoporous carbon and enhanced supercapacitance is explored. The impedance spectroscopy measurements (Nyquist diagram) apparently suggest a capacitance mechanism for the energy accumulation. Enhancement of the supercapacity is explained by light-generated carriers in low-dimensional nano-interfaces in relevant mechanism an increasing concentration of delocalized electrons resulting in unlocking of the Helmholtz layer capacity.

The surface of microporous Norit® GAC 830 W carbon was fluoroalkylated by heating in 1,1,1,2-tetrafluoroethane and 1,1,1,2,2-pentafluoroethane at 400 and 500 °C. Elemental analysis, FTIR ATR spectroscopy, and TG studies showed the presence of ∼0.1–0.7 mmol g−1 of the fluorine-containing groups. Nitrogen adsorption measurements and quenched solid density functional theory simulations proved an increase in the mesoporosity. By combining the results of solid-state 19F NMR and XPS analyses, we determined the functionalization of the carbon surface with CF, CF3, and CF2 fluorine-containing groups. Supercapacitor electrodes prepared from these materials were subjected to the charge-discharge tests and electrical impedance measurements. During galvanostatic cycling in the aqueous 30% KOH, they showed an enhanced charge capacitance compared to the parent (830 W) and the reference (Supra 30) carbons. These observations suggest that the fluoroalkylated surface and the modified microporous structure have an additive effect on capacitance parameters of carbon electrodes studied in symmetric, negative and positive modes. The fluoroalkylation caused an increase in the surface capacitance up to 38%. Herein, we demonstrate the fluoroalkylation is a simple way to increase a capacitance of carbon electrodes.

Two-dimensional nanofiber mats based on a mixture of polybenzimidazole with telechelic oligoperoxide are obtained by the method of electrospinning. It is shown that the reactive peroxide groups on the surface of nanofibers can be modified by the initiation of radical polymerization and grafting of various polymeric chains. The phenomenon of “negative” capacitance is detected for the impedance dependences of synthesized nanofibers. The influence of grafting of various polymeric chains to the surface of nanofibers on the polarization characteristics of nanocomposites is investigated. It is shown that some of the obtained structures are characterized by a combination of a low (< 1) tangent of dielectric losses in the infralow-frequency region (0.001–0.1 Hz) and high values of the dielectric permittivity (∼106). The possibilities of application of materials of this kind in the production of quantum batteries are discussed.

A new technological approach to the synthesis of multilayer nanostructures which allows their use in high-performance storage of electrical energy at the nanoscale level is discussed in this paper. In particular, the effect of co-intercalation of histidine (his), water and a solution of KOH into layered semiconductors of GaSe and InSe on the charge accumulation are studied. Based on the data of the cyclic current-voltage characteristics (CVC) a power storage mechanism (capacitive/pseudocapacitive) in each of these structures is described. This mechanism is in a good accord with the results of galvanostatic studies. The simulation of the parameters of the impedance equivalent circuit has been carried out, proving the possibility of using the described structures for nanoelectronics and nanoenergy devices. The observed values of tangent of electrical losses tgδ (

Molybdenum disulfide is obtained by the template method. Its structure and electrochemical properties are investigated. It was found that the working voltage of the LPS for molybdenum disulfide obtained by template method reaches 3 V, the specific capacitance is 180.9 F/g. It was identified that the electric energy storage device the positive electrode of which is molybdenum disulfide obtained by the template method has the discharge specific capacity of 238.9 F/g at a scan rate of 0.001 V/c.

The problem of coupling the porous structure of carbon materials with their electronic structure to achieve the maximum efficient operation of an electric double layer, i.e., the interfaces with the electrolyte, was considered. The initial materials for producing activated carbon were flax and field horsetail fibers. The effect of introducing iron-containing impurities into the initial raw flax material and natural silicon in the horsetail structure on the parameters of capacitive energy storage was studied. The investigation of the capacitance-voltage characteristics of the electric double layer, magnetic properties, and Raman spectroscopy data made it possible to propose a mechanism explaining the data obtained.

The dielectric constant and the loss tangent of such nanostructured materials as MCM-41 with encapsulated into its pores, the ferroelectric liquid crystal (LC) or rhodamine 6G and B dyes, as well as the characteristics of the intercalated GaSe by the L-aspartic acid (LAA) are investigated. Influence of microwave irradiation on characteristics of the MCM-41 nanohybrid and impact of illumination along the crystallographic c-axis on the GaSe nanostructure are described.

We have found that the structures based on ITO/tri(9-hexylcarbazol-3-yl)amine/Ca/Al fabricated by means of vacuum deposition generate acoustic oscillations when pulse voltage is applied. Impedance spectroscopy study indicates the presence of significant inductive response, which is the result of significant energy barriers at the semiconductor-metal interface. We assume that a very heterogeneous spatial distribution of the electric field at the organic/metal interface and the noncoplanarity of the molecules cause the electrostriction effect in the structures.

Three types of nanohybridized structures such as organic/dielectric, organic/semiconductor, and organic/graphen-like ones are investigated. The effect of ultrasonic exposure on the material structure and its influence on the dielectric permeability and on the dielectric loss tangent are studied for the first type of nanostructures. The magnetoresistance of a structure at room temperature is studied in the second type of materials. The change of the kinetic parameters of the intercalation process is shown for the third type of nanohybrid structures.

The multilayer structure consisting of alternating semiconductor (InSe) and molecular nematic (MN) nanointerlayers has been prepared using the intercalation techniques. The stages of the preparation of the InSe〈MN〉 structures have been described, and the results of investigation of their physical properties by impedance spectroscopy have been reported. The structures of the impedance models have been proposed, and prospects for their use as ultrahigh-capacitance varicaps and nanostructured elements of delay lines that can be directly incorporated into nanochips have been justified.

We report on stable in time organic photovoltaic devices based on metal-phthalocyanine structures, which were formed by vacuum deposition of nickel phthalocyanine (NiPc). The reported stability is due to ultra-thin zinc oxide (ZnO) layer formed at low temperature on top of the structure (beneath the metal contact) by atomic layer deposition (ALD) technique. We performed comparative analysis of current density–voltage characteristics and frequency dependencies of the impedance for freshly made ITO/NiPc/ZnO/Al and ITO/NiPc/Al devices and after storage during one month in air. We conclude that introducing of ultra-thin ZnO film into under-cathode region of ITO/NiPc/Al structure provides long-term protection of NiPc films from atmospheric effects.

The possibility is shown of designing a functional hybrid galvanophotocapacitor active system that would be able to use, if necessary, its own chemical energy in darkness instead of only the energy stored during illumination. In experiments, the Bridgman-grown n-type indium monoselenide was used as the photosensitive anode. Electrochemical investigations were carried out in a three-electrode cell with an aprotic solution of electrolyte; 0.4 M lithium-iodide solution in γ-butyrolactone acid and 1M lithium-tetrafluorborate in the same solvent were chosen as the latter.

Intercalation of gallium and indium selenide crystals by nickel initiates their electret polarization. The effect manifests itself at small concentrations of the intercalant. Temperature dependences of dielectric permittivity for both crystals demonstrate peaks in the same region of concentration. The effect is presumably connected with the ordering of local quasi-dipoles caused by the redistribution of intercalant atoms between octahedral and two tetrahedral positions. It is shown that a microscopic four-state model is able to reproduce a peak-like behaviour of the polarization at change of the intercalant chemical potential (concentration) and peculiarities of temperature dependences of the transverse dielectric susceptibility.

The effect of laser radiation on the impurity energy spectrum of intercalated structures is studied by the example of 〈Co〉0.015GaSe. By the variations in frequency dependences of resistivity measured normally to the layers of the obtained structure and by the transformation of the Nyquist diagrams consisting of two connected in series parallel R ‖ C units, a conclusion is made on the laser-stimulated compensation of the intercalant. The obtained values of the real part of permittivity are characteristic of doped semiconductors or their alloys in the radio-frequency range. The experimental results showed that the pulsed laser irradiation is an effective method to affect the energy impurity spectrum of intercalated compounds.

The mechanisms of the photoelectretic effect appearing on Ni intercalation GaSe were studied. The presence of the photoelectretic effect for such an object of investigation can be explained by the estimation that in Ni intercalated GaSe , the nonequilibrium electrons and holes excited by light occurred on an asymmetric potential well.

Intercalated crystals of indium and gallium selenide are prepared. It is shown that laser intercalation of nickel into GaSe samples leads to a giant magnetoresistive effect whose magnitude and sign depend on the concentration of the guest component. The giant magnetoresistive effect in the InSe intercalation compounds is considerably weaker and does not exceed 5%. The experimental data obtained are explained in terms of magnetic delocalization (localization) of charge carriers with the participation of states of intercalated magnetically active atoms in the vicinity of the Fermi level.

Within the framework of the Kronig-Penny model, changes in the electron spectrum of a layered crystal caused by intercalation are analyzed. Special attention is paid to both the geometric changes of the crystal and its energy characteristics during intercalation. The extraordinary behavior of the spectrum caused by the geometric intercalation factor is observed.

A new technological approach to the synthesis of multi-layer nanostructures is suggested; it enables us to ensure them unique properties and extraordinary possibilities of their practical application. In particular, it is shown that the synthesis of nanostructures of GaSe⟨β-cyclodextrin⟨FeSO4⟩⟩ hierarchy architecture in superposed electric and light-wave fields causes especially strong changes in their magnetic impedance response. In this case, the impedance response of the synthesized clathrate takes inductive character in the frequency range of 10−3–105 Hz. The relationship between the impedance behaviour of such hierarchical structures and frequency fractionality is investigated on the basis of Cettano equations. The prospect of application of the synthesized nanohybrids for active elements of gyrator-free nanolines of delay, for super-sensitive capacitance sensors of magnetic field and of light-wave field, and for quantum batteries at room temperature is shown.

First nano-hybridized clathrate/cavitant structure of hierarchical architecture was synthesized. The results of investigations of the properties of initial nanoporous silica matrices MCM-41, with encapsulated in its pores of β-cyclodextrin in cavitand and cavitat (with FeSO4) states and change at room temperature in a constant magnetic field intensity of 2.75 kOe, have been presented. Phenomenon of enormous magnetocapacitance and giant negative variable-current magnetoresistance has been discovered.

Double-matrix hierarchical structure of the 〈molecular-lattice matrix MCM-41〈hydroquinone〉〉 is synthesized. Its use in the cathode process in the Li +-intercalation current generation showed a significant improvement in the structure of the discharge curve and the practical constancy of diffusion coefficient throughout the discharge process. Theoretical model describing the peculiarities of observed characteristics in the structure is presented.

Heterophase nanostructures with alternate semiconductor and electrolytic seams are received. It is shown that the insertion of a polymer composition into the van der Waals gap of crystals causes the additional potential barriers in them. A non-monotone change of the resistance of the obtained structure under applied potential, as well as the strong low-frequency dispersion, has been found out, which can be due to the polarization of double electric layers.