This article inform about creating a new variant of humidity to electricity converter (HEC) based on different types of zirconia powders-double-layer HEC. The powders that were used in the work differ in chemical composition (Y-and Mg-stabilized ZrO2) and surface properties (positive and negative charged) and allow realizing the charge separation of moving water ions and generate the electric power under ion gradient diffusion in the presence of water molecules in the atmosphere without humidity gradient. Due to the opposite ionic conductivity with respect to protons and OH groups, this HEC separate charges more efficiently compared with converters operating only by the streaming potential mechanism under humidity gradient conditions. The resulting humidity to electricity converter can generate, for a long time, an open-circuit voltage of up to 120 mV combined with a power density of 2.2 mu W on the optimal load resistance. Reducing the internal resistance of the converter by adding graphite particles to both parts of the converter and creating a network of percolation paths for water ions and electrons made it possible to increase the open-circuit voltage to 0.16 V, reduce the internal resistance to 120 Ohm and increase the power to 56 mu W (4.7 mu W/cm2).

In this work, the influence of additives of rare earth and transition metals on the process of formation of the structure, mechanical and electrical properties of the SOFC electrolyte material based on zirconia was studied in order to identify the key technological and physical parameters affecting this process.A strong influence of the type of doping impurity on the lattice parameter of synthesized particles and sintered ceramics, on the strength and density of ceramics, and on the activation energy of ionic conductivity along grain boundaries was found. The effect of the type of additive on the value of ionic conductivity by grain volume in sintered ceramics was not detected.It was shown that the dopants effects on the ionic conductivity of zirconia electrolyte material in the indirect mode. The ionic radius of the dopants are determines the level of stability of the substitutional solid solution, and the diffusion of the impurity to the grain boundaries during sintering. It has been established that the more the ionic radius of the impurity differs from the equivalent ionic radius of the cation, the greater the activation energy of ionic conductivity along grain boundaries is observed. This depends on the degree of contamination of the grain boundaries with various impurities, which can diffuse to the grain boundaries and segregate there due to a violation of the Hume-Rothery rule. At the same time, the activation energy of ionic conductivity over the grain volume changes insignificantly, which indicates that the conductivity over the grain volume depends strongly on the number of oxygen vacancies, the concentration of which weakly depends on the ionic radius of the impurity.

It was shown the forming of Ag-contained ZnO-CeO2 composites occurs due to the complex decomposition and structure transformation of oxide materials and Ag-complexes. It allows us to realise one synthesised approach for obtaining photosensitive materials with different particle sizes, defects and kinds of architecture. The possible mechanisms of photosensitivity of these materials are determined. For composite nanoparticles (NP) with sizes up to 30 nm, the photosensitivity is connected with an abnormal decrease of bandgap energies at reducing NP sizes and an effective charge separation due to electron stocks on [& Scy;& iecy;3+...O2] centres and surface [Ce4+...O2- ] oxidative centres formation. The appearance of the hyperfine structure pattern of six lines centred at g =2.002 and split by 93-94 G in the ESR spectra of the composite structure confirms the realization of this mechanism. For more big NP sizes of this composite, the surface plasmon resonance plays a more significant role in the material's photosensitive properties. The position of surface plasmon resonance depends on the kind of realised structure. The phase composition, temperature and reduction determine the type of structure (NPs/AgNPs ore core/Ag shell) that will be recognised in the Ag-contained CeO2-ZnO system.

This study is devoted to the development of new oxide materials and devices based on them for direct long-term production of electricity from ambient humidity, which can be used as an auxiliary power supply system for self-sufficient buildings. The simplest device, a tablet pressed from these powders, generates an electrical potential in the presence of a moisture gradient inside the sample. The output voltage level of the converter depends on the type of material and the porous structure of the converter. There is a dependence of the sign of the output voltage on the type of material, which can be related to the type and sign of the surface centers of the converter material particles. The main mechanism of the converter operation is the generation of the streaming potential during the movement of adsorbed moisture (water molecules) in the porous structure of the converter under the influence of the ambient air humidity gradient. An increase in converter thickness increases the generation time of the output voltage by up to several tens of hours, both with an increase and a decrease in the humidity level in the compartment. The results of this study will help to use a huge reservoir of low-potential energy contained in gaseous water molecules to generate "green" electricity.

The dimensional effect of the accumulation of an electric charge with a density of up to 270 μF/g by the system of compacted zirconium dioxide nanoparticles during exposure in an electric field (5000 V/m) under normal physical conditions is determined. Based on a qualitative complex analysis of the forms of appearance of the effect, it is shown that the place of localization of different charge carriers is the surface of nanoparticles. The supposed mechanism of this effect is considered using the theory of dispersed systems, the band theory, and the theory of contact phenomena in semiconductors. It was concluded that this mechanism is due to the phenomenon of localization of electron-type charge nanoparticles in the near-surface zone of the material in contact with the adsorption ion atmosphere. This effect is relevant for modern nanoelectronics, microsystem technology, and printed electronics.

This study is devoted to creating media for the accumulation of electrical energy based on zirconia nanoparticles. The effect of charge accumulation by compacted zirconia nanoparticles, the manifestation of which depends on the size of the particles and the degree of hydration of their surface, was found. It is shown that for the system of hydrated nanoparticles, the formation of the dielectric constant of the entire structure as a whole is influenced by the dielectric properties of the nanoparticle materials and water on its surface. The difference in the dielectric properties of the filler (water) and the matrix (material of zirconia nanoparticles) leads to a strong increase in the dielectric constant of hydrated compacted nanoparticles due to the Maxwell–Wagner effect, which is a promising application in the development of energy storage media. Graphical abstract

The current transfer through a two-layer structure saturated with absorbed water, each layer of which consists of pressed ZrO2 nanoparticles with two sizes (10 and 20 nm), has been studied. The structure was obtained using the isostatic pressing the ZrO2 + H2O powders. The form of current–voltage characteristics inherent to the studied structure, that has diode properties with the rectification coefficient close to 3, has been explained by the appearance of a potential barrier at the interlayer boundary.

The engineering of doped zirconia nanoparticles (NPs) for energy application is realized in concept Research Smart Laboratory. To improve nanomaterials’ engineering, correlations of “salt concentration—powder dispersity” and “calcined temperature—particle’s sizes” were built. The correlation of “materials structure—materials functionality” is made. The technology forming ceramics with varying grain sizes and densities under the same thermodynamic conditions (1350 °C) from NPs with different sizes is developed. The impedance spectroscopy with the distribution of relaxation time analysis is used for ionic conductivity ceramic investigation in range 240–900 °C. The activation energies of the grain and grain boundary oxygen diffusion are calculated. It was shown that the energy activation of bulk oxygen diffusion does not depend on ceramic grain size (Ea = 0.9 eV). The energies activation of grain boundary oxygen diffusion estimated in the framework of the bricklayer model show a weak growth with the rising of ceramic grains sizes. The values of the volume activation energy are close to the grain-boundary activation energy for ceramics obtained from nanoparticles smaller than 18 nm. It was found that the grain boundary space contains two types of elements with different geometries. The size of NPs used for ceramic determines the size of grain boundaries elements. It was shown that the density of sintered ceramic has a more substantial effect on its electrophysical properties than grain size. The NPs sizes of 18–24 nm are optimal for forming pressed powder compacts and sintered ceramics with high density.

Two series of ZrO2 samples—pure ZrO2 and ZrO2 doped by 3% of Y2O3—prepared at 400, 500, and 600 °C were studied. The samples were characterized by powder XRD, TEM, SANS, IR spectroscopy, and nitrogen adsorption at 77 K. Monoclinic ZrO2 was the dominating phase in the samples of pure zirconia, while Y-doped zirconia mainly consisted of tetragonal ZrO2. An increase in the calcination temperature led to the growth of the zirconia nanoparticle (NP) size and a decrease of the specific surface SBET. The size of Y-doped zirconia NPs (9–16 nm by XRD) was smaller compared to pure ZrO2 (12–19 nm), synthesized at the same temperatures. The content of the surface defects in the tetragonal Y-doped ZrO2 was estimated by analysis of IR spectra and other indicators and grew with the increase of the calcination temperature. The strength and content of the acidic surface sites were determined by potentiometric titration. The doping of ZrO2 by Y3+ led to the formation of the sites with lower pKa. The catalytic activity of ZrO2 and Y-doped ZrO2 in the reaction of α-tetralol oxidation by m-chloroperoxobenzoic acid was studied, and it was found that α-tetralone was the main product. The catalytic activity of the Y-doped zirconia samples in α-tetralol oxidation, expressed as conversion or turnover frequency (TOF) per 1 m2 or ZrO2, increased with the increase of the total concentration of the surface acidic centers.

The paper considers the new effects of the nanoscale state of matter, which open up prospects for the development of electronic devices using new physical principles. The contacts of chemically homogeneous nanoparticles of yttrium-stabilized zirconium oxide (ZrO2—x mol% Y2O3, x = 0, 3, 4, 8; YSZ) with different sizes of 7.5 nm and 9 nm; 7.5 nm and 11 nm; and 7.5 nm and 14 nm, respectively, was studied on direct current using nanostructured objects in the form of compacts obtained by high-hydrostatic pressure (HP-compacts of 300MPa). A unique size effect of the nonlinear (rectifying-type contact) dependence of the electrical properties (in the region U < 2.5 V, I ≤ 2.7 mA) of the contact of different-sized YSZ nanoparticles of the same chemical composition is revealed, which indicates the possibility of creating semiconductor structures of a new type (homogeneous electronics). The electronic structure of the near-surface regions of nanoparticles of studied oxide materials and the possibility of obtaining specifically rectifying properties of the contacts were studied theoretically. Models of surface states of the Tamm-type are constructed considering the Coulomb long-range action. The discovered energy variance and its dependence on the curvature of the surface of nanoparticles made it possible to study the conditions for the formation of a contact potential difference in cases of nanoparticles of the same radius (synergistic effect), different radii (doped and undoped variants), as well as to discover the possibility of describing a group of powder particles within the Anderson model. The determined effect makes it possible to solve the problem of diffusion instability of semiconductor heterojunctions and opens up prospects for creating electronic devices with a fundamentally new level of properties for use in various fields of the economy and breakthrough critical technologies.

The dimensional effect of electric charge storage with a density of up to 270 μF/g by the hydrated ZrO2-nanoparticles system was determined. It was found that the place of localization of different charge carriers is the generalized heterophase boundary-nanoparticles surface. The supposed mechanism of the effect was investigated using the theory of dispersed systems, the band theory, and the theory of contact phenomena in semiconductors, which consists of the formation of localized electronic states in the nanoparticle material due to donor–acceptor interaction with the adsorption ionic atmosphere. The effect is relevant for modern nanoelectronics, microsystem technology, and printed electronics because it allows overcoming the basic physical restrictions on the size, temperature, and operation frequency of the device, caused by leakage currents.

The paper considers new effects of the nanoscale state of matter, which open up prospects for the creation of electronic devices using new physical principles. The contact of chemically homogeneous different sizes hydrated nanoparticles of yttrium-stabilized zirconium oxide (ZrO2 – x %mol Y2O3, x=0, 3, 4, 8; YSZ) with particle sizes of 7.5 nm and 7,5 nm; 7.5 nm and 9 nm; 7.5 nm and 11 nm; 7.5 nm and 14 nm in the form of compacts obtained using high hydrostatic pressure (HP-compacts of 300MPa) was studied at direct and alternating current. A unique size effect of the nonlinear (semiconductor) dependence of the electrical properties (in the region U <2.5 V, I ≤ 2.7 mA) of the contact of different-sized YSZ nanoparticles of the same chemical composition is revealed, which indicates the possibility of creating semiconductor structures of a new type based on chemically homogeneous nanostructured systems. The electronic structure of the near-surface regions of nanoparticles of a special type of oxide materials and the possibility, on this basis, to obtain specifically rectifying properties of the contacts were studied theoretically. Models of surface states of the Tamm type are constructed, but considering the Coulomb long-range action. The discovered variance and its dependence on the curvature of the surface of nanoparticles made it possible to study the conditions for the formation of a contact potential difference in cases of nanoparticles of the same radius (synergistic effect), different radii (doped and undoped variants), as well as to discover the possibility of describing a group of powder particles from material within the Anderson model. The established effect makes it possible to solve the problem of diffusion instability of semiconductor heterojunctions and opens up prospects for creating electronics devices with a fundamentally new level of properties for use in various fields of the national economy and breakthrough critical technologies.

Anticorrosion activity of isomeric 1,3-thiazolothiadiazine-S,S-dioxides was studied by electrochemical and gravimetric methods in a model corrosion-inducing environment (in 0,5 M solution of NaH2PO4 center dot 2H(2)O at pH = 9,5 divided by 11,5 and t = 25 degrees C). Analysis of the obtained results showed that the derivatives of 2,6-diaryl-2H,4H-[1,3]-thiazolo[3,2-c][1,3,5]thiadiazine-3,3-dioxides (R-(TD-3,3), where R = H; 4-Me; 4-Et; 4-NH2; 4-NMe2; 4-OMe; 4-OEt; 4-Br; 4-Cl; 4-NO2) provide corrosion inhibition for zinc and copper. Moreover, the nature of a substituent in 1,3-thiazolothiadiazine-S,S-dioxides has little effect on the isomer ratio, but significantly affects their anti-corrosion efficiency. Introduction of substituents of different nature into the R-(TD-3,3) molecule can result in the effect on the efficiency of protection being opposite for zinc and copper. Electrophilic groups in the molecule can increase protective effect for copper, but decrease it for zinc. On the contrary, nucleophilic groups are beneficial for protection of zinc, but less effective for copper. Considering that derivatives of 1,3-thiazolothiadiazine-S,S-dioxides are noticeably hydrophobic and are capable of forming hardly soluble coordination complexes with metal ions, it is advisable to use them for anti-corrosion protection of copper and zinc surfaces in phosphate solutions. Copyright (C) 2022 Elsevier Ltd. All rights reserved.

Structure, optical and photocatalytic properties for wide band gap oxide doped zinc oxide are investigated by XRD, ESR and UV-visible spectroscopy.It was shown the introduction of Al2O3 or ZrO2 led to form of structural defects in zinc oxide matrix.According ESR data a small amount of ZrO2 (0.01 mol.%) in ZnO forms a defects of donor nature, while the same amount of Al2O3 in ZnO matrix led forming as acceptor and as donor defects.Observed tail and shift of optical band gap confirmed ESR data.It was shown the increasing of donor defects in structure ZnO led to increase of photocatalytic activity to phenol degradation.It was shown the dopant types also determined a kind of intermediates of phenol degradation and possible mechanism.For Ag-decorated doped ZnO it is also shown that mechanism of phenol degradation contain a redox cycle.It was shown the bactericide activity of Ag-decorated ZrO2-doped ZnO to S.aureus is better than E.coli.

The influence of the amount of F-agent on the characteristics of nanoparticles (NPs), instant phase stability, the NPs shape and the process of NP crystallization are discussed. The structural reorganisation in F-modified amorphous xerogel aggregates leads to the formation of anisotropic-shaped crystallites under the crystallization of such xerogel. The kinetic parameters of crystallization are estimated. It was shown the main mechanism of crystalization is crystal growth controlled by interface reaction and bulk nucleation occurs with constant number of nuclei. The change of mechanism from 3-dimensional growth for pure zirconia to 2- or 1-dimensional growth for modified systems with the increasing of F-amounts is observed. It reflects the change of the morphology of crystal from sphere for pure zirconia to parallelopipedon and needle shapes for F-modified zirconia with high F-content. The increasing of E-a value of F-modified xerogels in comprison with an unmodified system is observed.

XRD, ESR, TRMC and UV–visible spectroscopy are used for the description of characteristics of investigated systems and determination of forming structure mechanism in Al, Zr or Ce doped non-stoichiometric ZnO1−x. It was shown the Al and Zr ions substitute the lattice Zn2+ in the ZnO matrix, and as a result, the donor's levels form in ZnO bandgap and acceptor’s level of zinc vacancy. Last level is a trap of phogenerate holes in material and it allows to delay photocatalytic actvity Al- and Zr-doped ZnO. Ce ions incorporate as interstiallite ions or segregate on crystal surface that leads to appearance the f-levels in the bandgap of ZnO, and as a result, the cerium ion will trap for electron. It decreases electron lifetime or increases of hole lifetime and also if cerium ion segregates on the ZnO surface the set of reactions (Ce4+ + e- = Ce3+, Ce3+ + O2 = Ce4+ + O2−) may occur. It leads to form additional reactive oxygen species, in particular, super-anion radicals (O2−, ROS) that improve the activity of the material. As a result, the increasing of phenol degradation by 30% compared to pure ZnO may be achieved at the choice of Ce-doped ZnO catalyst.

The effect of the filler - the nanoparticles of zirconium (IV) oxide (16.5 nm) on the thermal stability of composites based on epoxy resin ED-20, isomethyltetrahydrophthalic anhydride, complex catalyst, and plasticizer has been studied. The yield of the sol fraction of composites with different content of ZrO2 nanoparticles has been evaluated by the derivatography method. The resistance of the obtained polymers and composites to thermal oxidative degradation has been evaluated by derivatography. Evaluation of the effectiveness of the influence of ZrO2 on the curing has been carried out according to the data of differential scanning calorimetry (DSC) by the Kissinger method. The optimal content of ZrO2 in the composition has been established.

It was shown that Ag(or Ag2O)–ZrO2–Y2O3 formation occurs due to the complex process of decomposition and structure transformation of oxide materials and Ag-complexes. Differences in the decomposition temperatures of Ag-complexes, in particular, and their melting temperatures, and the transformation of ZrO2–Y2O3 NPs morphology leads to the creation of composite structure of two types: an Ag–NPs/zirconia matrix and zirconia core/Ag-shell. It was shown that for these composites the temperature is an effective approach for controlling the NPs sizes for both components (Ag clusters and zirconia NPs), the defectiveness of the complex oxide and their optical properties, in particular the photosensitive to visible irradiation range.

For investigation of the influence of temperature of nanopowder calcination on adsorption properties of zirconiananoparticles, the pH-metry method was used. As a result, structure and parameters of double electric layer surrounding zirconia nanoparticles under wetting were calculated. According presented data, titration curves of suspensions based on zirconia nanoparticles at different electrolyte concentrations intersect at values other than sigma(0) = 0, which indicates the occurrence of specific sorption on the surface of zirconia nanoparticles.