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Open Access
Wireless power transmission technology
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-10) Zhadyra, Bolat; Symbat, Temesheva; Uakaskan, Baydeldinov
The technology of wireless power transmission is truly revolutionary for the current society, because it is already beginning to be widely used today. Although the first large-scale experiments were conducted by Nikola Tesla just over a hundred years ago, this technology has only now moved to a more global level. And we can say with confidence that in the near future it will become one of the fundamental ones in the process of direct development. Nowadays, wireless transmission of energy is widely considered in electronics area. For instant, if we want to charge kitchen equipment, the easiest way to do this is to use inductors. The principle here is very simple. 2 coils are taken and placed close to each other. One of them is powered. The other plays the role of a receiver. When the current in the power supply is adjusted or changed, the magnetic flux on the second coil also automatically changes. As the laws of physics say, an EMF will arise and it will directly depend on the rate of change of this flow. It would seem that everything is simple. But the flaws spoil the whole rainbow picture. There are three cons like: low power, short distance, low efficiency. These main disadvantages are the questions that scientists want to solve.
Open Access
Silicon solar cells textured using gold of induced etching
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Dikhanbayev, K.K.; Shabdan, Ye.; Sagidolda, Ye.; Bayganatova, Sh. B.; Mussabek, G. K.; Zhumatova, Sh.A.
As is known, a layer with a dielectric coating remains the standard of a photoelectric converter and many research groups are studying various alternative methods to achieve an antireflection effect in silicon for photovoltaic and other optoelectronic applications [1]. Some of these methods include electrochemical etching [2], sol-gel deposition [3], magnetron sputtering of metal oxide films [4], and anisotropic etching [5]. Ready-made structures with a p-n junction were used as the initial substrate, the specific resistivity of the n+ layer was 0.008-0.01 Ohm∙cm and the total plate thickness was 300 μm. Then, the front side of the sample is chemically activated in a solution of 0.4 mM, HAuCl4 for 3-5 s, after which it is thoroughly washed in deionized water. The output parameters of solar cells were determined from the characteristics. In particular, open circuit voltage Uoc = 610 mV, short-circuit current Isc = 32 mA / cm2, duty cycle ξ = 0.77, light emission power Pmax = 100 mWt /cm2, efficiency is ~ 15.03%.
Open Access
Composite PAAm-based hydrogel electrolyte for hybrid aqueous (Zn-Li-ion) battery
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Zhanadilov, Orynbay; Mentbayeva, Almagul; Beisbayeva, Zhanna; Amze, Magzhan; Bakenov, Zhumabay
Hybrid aqueous rechargeable batteries are very attractive alternative to conventional rechargeable lithium ion batteries for stationary application because of production and usage safety, reduced production cost and environmental friendliness. Previously aqueous rechargeable batteries with Zn/LiCl-ZnCl2/LiFePO4 system with liquid electrolyte has been reported [1]. The system performed a high rate capability up to 60 C with the average operation voltage 1.2 V and cycling performance with a capacity retention of 80 % over 400 cycles at 6 C. However, there are several drawbacks including water decomposition and zinc dendrite formation hindering the commercialization [1]. The present study aimed to develop a PAAm-based hydrogel electrolyte with inclusion of montmorillonite and halloysite clay nanoparticles for hybrid aqueous rechargeable zinc/lithium ion batteries to overcome above mentioned problems. Polyacrylamide hydrogel was chosen because of its high ionic conductivity, high water content and simple fabrication method in which cross-linking degree, thickness, etc. were optimized. Inclusion of clay could improve mechanical stability of hydrogel electrolyte, prevent water decomposition and dendrite formation. All tests performed in Zn/LiFePO4 cell operating in an optimized LiCl/ZnCl2 aqueous electrolyte based hydrogel.
Open Access
Hydrothermal Low-cost Synthesis of ZnO-GO Nanocomposites
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Kedruk, Y.Y.; Alpysbaiuly, N.; Gritsenko, L.V.; Abdullin, Kh.A.
One of the best known multifunctional semiconductor oxide materials is zinc oxide (ZnO). The wide band gap, high binding energy of exciton, radiation resistance, and high chemical stability make it a promising material for sensors [1], LEDs, solar cells, piezoelectric devices, transistors, etc. Recent studies have shown that composite materials based on ZnO and graphene oxide (GO) can have optical and electrical properties superior to those of ZnO [2]. This work is devoted to the development of the synthesis of photocatalytically active composites based on ZnO and graphene oxide by simple, low-cost effective methods. Graphene oxide was obtained by the Hammers method and then added to a solution for hydrothermal synthesis of zinc oxide. To form zinc oxide nanoparticles, a solution of sodium hydroxide NaOH at room temperature was added dropwise to a glass beaker with a solution of zinc acetate (CH3COO)2Zn×2H2O, after which the entire solution was thoroughly mixed on a magnetic stirrer for another 15 minutes. The resulting precipitate was washed with distilled water, separated by centrifugation, and then dried in an oven at 125ᵒC for 12 hours. The morphology, structural properties, and photocatalytic activity of the synthesized ZnO-GO samples were studied. Measurement of the photocatalytic activity of the obtained samples was carried out in relation to the degradation of Rhodamine-B (RhB) dye. It was noted that an increase in the GO concentration in the ZnO growth solution makes it possible to obtain more photocatalytically active ZnO – GO composites. Figure 1 shows the morphology of the ZnO-GO powder, containing 0.005 wt% GO, and the change in the optical density spectra of an aqueous solution of RhB in its presence.
Open Access
Conformal coating of LTO/PAN for high performance Si nano-composite anodes
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Mukhan, Orynbassar; Nurpeissova, Arailym; Bakenov, Zhumabay
Silicon is a potentially promising anode material for the next-generation energy storage devices owing to advantages as low cost, low toxicity and high specific capacity. However, there are several disadvantages of the silicon that shorten the life time of the battery such as instability of SEI layer, low electrical conductivity and volume change [1]. Huge volume expansion (>300%) during the lithiation/delithiation processes, which results in the pulverization of Si particles and fast capacity loss of the anode material, is considered as a major problem [2]. To be implemented commercially Si nanoparticles should exhibit high-power and low volume change. So far, there have been no credible Si-based materials reported satisfying all of these requirements [3]. Here, we report modified Si nanoparticles co-coated with Li4Ti5O12 and cyclized polyacrylonitrile targeted to enhance the conductivity and tolerance to volume change. The synergistic effect from both coating provide the Si electrode with good conductivity and better performance. Synthesized Si/LTO/cPAN composites were characterized by X-ray diffraction (XRD) and Scanning electron microscopy (SEM) to identify the structure and morphology of composites.
Open Access
ZnO-CoO Nanopowders for Asymmetric Supercapacitors
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Nurbolat, Shyryn; Zhumakhanov, Zharkyn; Kalkozova, Zhanar; Abdullin, Khabibulla
Zn1-xCoxO nanopowders were obtained by chemical bath deposition followed by thermal annealing. The structure and morphology of the samples were studied by X-ray diffraction analysis and scanning electron microscopy. Raman spectra were studied at room temperature using a Solver Spectrum (NT-MDT) spectrometer with laser excitation at 473 nm. Depending on the synthesis conditions, nanopowders with an average size of 1-2 nm were obtained. It was shown that while chemical precipitation from a solution of zinc nitrate allows to obtain zinc oxide, and chemical precipitation from a solution of cobalt nitrate results in cobalt hydroxocarbonate, the presence of zinc and cobalt in equal molar concentrations inhibits the growth of both zinc oxide and cobalt hydroxocarbonate. The growth mechanism in the case of equal molar concentrations of zinc and cobalt in the growth solution changes dramatically. The resulting material is transformed by annealing in air into ZnCo2O4 oxide. However, it can be easily transformed by annealing at 350 °C in hydrogen atmosphere into a ZnO-CoO solid solution having a ZnO-type hexagonal lattice. The obtained fine powder of ZnO-CoO solid solution has an average crystallite size of 1-2 nm, depending on the conditions of preparation, and optical absorption spectra indicate the presence of doubly charged cobalt Co2+, which is in a tetrahedral environment. XRD and Raman results show that a single-phase Zn0.5Co0.5O solid solution is obtained, which consists of a hexagonal phase of the ZnO type. Electrodes from the obtained material showed a high specific capacity.
Open Access
Results of thermal stability tests of the IGR reactor HEU fuel
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Samarkhanov, Kuanysh; Gordienko, Yuriy; Ponkratov, Yuriy; Bochkov, Vadim; Tulubayev, Yevgeniy
The use of highly enriched uranium-graphite fuel (HEU fuel) in research reactors is of great concern to the world community due to the danger of nuclear material proliferation suitable for nuclear weapons fabrication. In this regard, large-scale work is currently being carried out at the IAE NNC RK related to the conversion of two unique research reactors IVG.1M and IGR, which should be subjected to a procedure with a decrease in fuel enrichment from 90% to 19.75% U- 235 (LEU fuel). Individual solutions for the nuclear fuel design of batch reactors pose high requirements for the designers of a new low-enriched fuel. Before the IGR reactor is conversed to LEU fuel, it is required a series of tests, one of which is the high temperature stability of fuel under cyclic process of heating-cooling conditions. This paper describes the experimental procedure and thermocyclic test results of a HEU fuel sample. The results of thermocyclic tests of a HEU fuel sample will be a reference when comparing with the results of thermocyclic tests of HEU fuel samples. Therefore, the main criteria for the suitability of using LEU fuel in the IGR reactor will be mass loss of the sample during thermal cycling, which should not exceed the values obtained during the test data with HEU fuel. The tests have been carried out at the TiGrA experimental complex, created on the basis of the TGA/DSC 3+ thermogravimetric analyzer and ThermoStar mass spectrometric gas analysis system. As a result of testing the HEU fuel sample, 100 heating-cooling cycles were carried out in the temperature range from 150°C to 1100 °C with a heating rate of 100 °C/min and cooling rate of 50 °C/min. In this case, the change in the sample mass and the gas phase composition above the sample were recorded.
Open Access
Sputtering of alkali metals into a gas medium upon excitation by products of nuclear reaction 6Li(n,α)3H
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Samarkhanov, Kuanysh; Khasenov, Mendykhan U.; Gordienko, Yuriy; Ponkratov, Yuriy; Bochkov, Vadim; Tulubayev, Yevgeniy
Uranium fission fragments, as well as products of 3He(n,p)3H and 10B(n,α)7Li nuclear reactions were used in the nuclear reactor for gas ionization and excitation [1, 2]. The use of a nuclear reaction with lithium-6 with thermal neutrons was studied to a less extend, before our works [3, 4]. The large mean free path of tritium nuclei in lithium (130 μm) and gaseous media (35 cm in atmospheric pressure helium) makes it possible to excite large volumes of gases and provide a larger amount of power nested in the gas in comparison with reaction products with 10B. Several modification of irradiation devices with a lithium cell for reactor experiments were constructed. At studying luminescence of noble gases with excitation by nuclear reaction products: 6Li + n → 4He (2,05 MeV) + 3H (2,73 MeV), (1) it was found, that at a temperature of the lithium layer of~500 K, lines of lithium, as well as impurities of sodium and potassium in lithium appear in the spectrum [4, 5]. The vapor density significantly exceeding density of saturated lithium vapor during ordinary thermal heating of lithium is generated by the α-particles and tritium nuclei released from the lithium layer, as well as when the opposite wall is bombarded [5]. It was noted that the population of the lithium atom levels almost has no any effect on the population of 2p-levels of a noble gas atoms. The main channel leading to the population of lithium levels, apparently, is the Penning process (R is a noble gas atom): R(1s) + Li → R + Li+. Excitation of sputtered lithium atoms occurs as a result of further plasma-chemical reactions in a gas.
Open Access
Polymer Physics and Modeling of Polycarboxylate-based Superplasticizers
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Ainakulova, Dana; Rakhmatulla, Samal; Karibayev, Mirat; Mentbayeva, Almagul; Wang, Yanwei
The tendency of developing urban areas brought a great demand for building materials in the last few decades. The innovation of new chemical admixtures has an increment in industry improving the rheology and early strength of cement-based material [1,2]. The use of modified polycarboxylate-based (PCE) superplasticizers in ready-mix or precast concrete cuts off required energy for construction decreasing the curing temperature and cost of building material. Moreover, the addition of superplasticizers results in a significant reduction to the annual worldwide CO2 emissions. Therefore, a continuous development of the PCE superplasticizers would be benign for us all if one considered the big picture of reducing the consumption of natural resources and energy. The research is a computational study, and our objective is to explore the polymer physics of PCE superplasticizers in aqueous solution and at liquid/solid interfaces using both the all-atom Molecular Dynamics (aaMD) and the Coarse-grained Molecular Dynamics Simulation (CGMD) simulation methods. More specifically, we are going to study (i) the interactions between PCE fragments and the various ions in a cement pore solution and how ions distribute around those PCE fragments; (ii) interactions of C-S-H surfaces with ions and calculations of the surface zeta potential [3]; and (iii) interactions between PCE fragments and C-S-H surfaces in the presence of ions using the aaMD simulation method. The aaMD method has a spatial resolution on the scale of a single atom, which is a great advantage when studying the physics of interfaces. However, it is rather computationally demanding to simulate polymers using the all-atom model, and that’s why we choose to work with PCE fragments instead of the entire macromolecule. The downside is that this choice may limit us from studying the polymer physics of PCE polymers [4]. In order to simulate the actual PCE polymers used in industry, we apply the CGMD simulation method by first developing coarse-grained models for PCE polymers in aqueous solution and then apply the same polymer model to study their conformational and adsorption properties at liquid/solid interfaces. We are particularly interested in exploring the physics of PCE polymers, which are comb-shaped copolymers with negatively charged backbones and neutral side chains, in the vicinity of a negatively charged surface with the presence of multi-valent cations [5].
Open Access
Synthesis of nitrogen-doped zinc oxide nanostructures and their application in antibacterial activity against e.coli, lactis, aerogenes, s.marcescens
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Issayeva, Saule; Kabylda, Anar; Xie, Yingqiu; Fan, Haiyan
The nanoparticles made of zinc oxide are well known because of their broader applications in various optoelectronic devices. The current work was dedicated to the synthesis, characterization, antibacterial testing and statistical assessment of the N-doped zinc oxide nanostructures (N-doped ZnO-NStr). The nanostructures were prepared via a hydrothermal treatment of zinc nitrate and ethylenediamine at 200oC for 3 h. The bacterial activity of synthesized N-doped zinc oxide nanostructures were tested on four different bacterial species: E.coli, Lactis, Aerogenes, S.marcescens at the range of concentration of the N-doped ZnO-NStr (0.078-0.78 mg/ml), estimated by UV-visible spectrophotometry. The bacteria were prepared with LB broth at the ratio 1:500000. The assessment of the results revealed that the low concentration (0.078-0.15 mg/ml) of the N-doped ZnO-NStr enhances the bacteria growth and the high concentration (0.78 mg/ml) of the nanoparticles reduces the population of bacteria. The N-doped zinc oxide nanostructures were well characterized by fluorescence spectroscopy, atomic force microscopy, Fourier transform infrared spectroscopy. Statistical assessment was also conducted for the bacterial pathogens with synthesized nanoparticles.
Open Access
Effective penetration depth of optical radiation in nanoscaled modified Ge2Sb2Te5 films
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Zhakypov, Alibek; Maksimova, Suyumbika; Prikhodko, Oleg; Ismailova, Guzal; Turmanova, Kundyz; Tolepov, Zhandos
Thin films of Ge-Sb-Te (GST) chalcogenide semiconductor materials and, in particular, Ge2Sb2Te5 composition, are used for creation of optical information carrier on the basis of a “glass-crystal” reversed phase transition. To improve information recording parameters, GST compositions are modified with an admixture of metal. In this case, the impurity must be isovalent and isomorphic with one of the components of the matrix. For the Ge2Sb2Te5 composition, one of these impurities is silver. The report presents the results of study of the optical properties of nanoscale amorphous and crystalline Ge2Sb2Te5 films modified with Ag, and spectral dependence of the effective depth of penetration of optical radiation into these materials deff (λ) are also presented. Amorphous Ge2Sb2Te5 films modified with silver (a-Ge2Sb2Te5) were obtained by ion-plasma RF (13.56 MHz) magnetron sputtering of a combined target from a polycrystalline of Ge2Sb2Te5 and Ag. The film thickness l was ~ 100 nm, and the silver impurity concentration in the films was reached 5 at.%. Crystallization of the amorphous films was carried out by thermal heating. The phase state of the film structure was monitored using Raman spectroscopy. The optical properties of the films (transmission spectra T(λ) and reflection R(λ) of light) were recorded on a Shimadzu UV2000 spectrophotometer in the range from 300 to 1100 nm. The spectral characteristics of light absorption α(λ) of the films were calculated from the expression α(λ) = -1/l·{ln[T(λ)/(1-R(λ)2]}. The effective penetration depth deff (λ) of the optical radiation for the films was determined from the relation deff (λ) = 1/α(λ). Analysis of the spectral dependences deff (λ) for amorphous and crystalline Ge2Sb2Te5films showed that the effective depth of light penetration decreases significantly with increasing impurity concentration. In с-Ge2Sb2Te5crystalline films, it is much smaller than in amorphous a-Ge2Sb2Te5 films. The obtained results are important for creating optical information carriers based on nanoscaled Ge2Sb2Te5films using radiation from lasers with different wavelength.
Open Access
Effect of Ag impurity on the optical properties of GST225 thin films
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Turmanova, Kundyz; Prikhodko, Oleg; Ismailova, Guzal; Zhakypov, Alibek; Maksimova, Suyumbika; Tolepov, Zhandos
Intensive research is currently underway to develop materials for the optical recording of information based on a glass-crystal phase transition. Promising materials for this direction are thin films of chalcogenide semiconductors based on the Ge-Sb-Te system. To improve the parameters of recording and rewriting information, the speed of the phase transition, the number of write-erase cycles used the impurity modification with metals such as Ag, In and Bi. It was found that Ag atoms act as nucleation centers that can reduce the activation energy of crystallization and increase the crystallization rate of the film, thereby erasing the PCRAM erasure rate [1]. The report presents the results of the influence of silver impurity and size effect on the optical properties of Ge2Sb2Te5 (GST225) films. Nanosized films GST225 modified by Ag were obtained by ion-plasma RF magnetron sputtering of a combined target from GST225 and Ag in an Ar atmosphere. The used power of the RF generator was selected in such a way as to produce GST225 films with an amorphous structure. Crystallization was performed by thermal annealing at 300°C. The films’ thickness range ~50-150 nm and was determined on the Quanta 3D 200i SEM. The concentration of silver impurities in the films was 5.0 and 9.7 at. %. The optical properties of studied films deposited on glass substrates were investigated using Shimadzu UV2000. It was found that the spectral dependences of the transmission coefficients T(λ), absorption α(hν), and the optical band gap Eg depend both on the concentration of Ag in the films and on their thickness. It was found that for amorphous and crystalline GST225 films in the range of the studied Ag impurity concentrations and their thicknesses, the quadratic law of light absorption is observed, which indicates the realization of indirect allowed optical transitions. Modification of amorphous and crystalline GST225 films with silver impurities leads to a substantial decrease in the optical band gap. At a fixed concentration of Ag impurity in GST225 films in the amorphous and crystalline state, with a decrease in their thickness to 50 nm, a significant decrease in Eg is also observed. Thus, the modification of GST225 films with an Ag impurity leads to significant changes in their structure and optical properties.
Open Access
Enhanced gas sensing properties of IZO thin films using SILAR
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Soltabayev, Baktiyar; Mentbayeva, Almagul; Çağırtekin, Ali Orkun; Acar, Selim
In the last decades, resistive gas sensors based on semiconductor oxides have been the topic of interest for a long time due to their high sensitivity to both oxidizing and reducing gases. These sensors meet the main market requirements such as low cost, small size, and easy maintenance. Currently, much attention has been attracted to finding an effective method to improve the nanomaterials’ sensing ability and selectivity. Sensor devices based on semiconductor oxide like ZnO are important sensing material for detection of hazardous gases [1]. ZnO is the most extensively applied as a gas sensing material, since it has remarkable characteristics necessary for an ideal metal oxide gas sensor such as wide band-gap energy (Eg=3.37 eV) and high binding energy (Ee=60 meV) [2]. Several approaches have been applied to improve gas sensing performance, for instance, morphological changes by doping metal. Especially, indium (In) significantly influences the electrical, chemical, structural, and gas sensing properties of ZnO. In the present work, the effect of In doping on the various properties of ZnO was investigated. The pure ZnO and indium doped ZnO thin films have been synthesized by the SILAR method. The obtained results clearly demonstrated a significant improvement in gas sensitivity by incorporating In into the ZnO.
Open Access
Solar cell research at an altitude of 3340 meters above sea level
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Sadykov, T.Kh.; Zhukov, V.V.; Iskakov, B.A.; Nevmerzhitskiy, I.S.; Serikkanov, A.S.; Novolodskaya, О.А.; Tautayev, Y.М.
Providing electricity to consumers in the mountainous regions is one of the urgent problems of power engineers. Laying and maintenance of power lines is expensive because of the difficult terrain and climatic conditions Providing a heating system for heating boilers, requires the acquisition and delivery of large quantities of combustible material. The heating season in the highlands lasts up to nine months. Considering all the costs of electricity consumption and heating, it becomes necessary to conduct research and evaluate the economic efficiency of using solar power plants, focused on providing electricity to consumers in mountain regions. In order to create a scientific basis for solving innovative problems in solar energy at the Tien Shan high-mountain cosmic ray scientific station (TSHSS), located at an altitude of 3340 meters above sea level, initiative work is underway to create a solar power station (SPS), assess its effectiveness, safety , environmental friendliness and reliability in work. At the moment, a solar power station has been created at an altitude of 3340 meters above sea level. A comparative analysis of the results of generating electricity from the same type of solar power plants located at altitudes of 800 and 3340 meters above sea level was carried out. It is shown that the amount of electricity generated by a solar power plant at an altitude of 3340 is 20 percent more than at an altitude of 800 meters.
Open Access
New composite material for both biodegradable electronics and soft biomedical electronics
(2020-08-06) Yedrissov, Azamat; Khrustalev, Dmitriy; Khrustaleva, Anastassiya; Vetrova, Anastassiya
The study of biodegradable polymers is in the focus of scientific interest, which is due to their increasingly diverse applications. Biodegradable polymers are widely used in the manufacture of packaging materials, cases for various products. In addition, they are used for various fields of medicine - from biodegradable prostheses to soft biomedical electronics [1-3]. A new method for the production of Printed Circuit Boards (PCBs) based on polylactic acid and natural silk is proposed in this paper. The originality of our proposed method is to replace the currently used environmentally hazardous polymer binders with biodegradable polymers based on Polylactic acid and its copolymers. Experimental data have shown that the obtained rigid laminate for the production of PCB has a number of practically useful characteristics: it is relatively resistant to environmental factors; has good properties: durability, lightness, low electrical conductivity, good adhesion to both hydrophilic and hydrophobic materials, can be made from renewable sources and can be completely recycled into low-molecular-weight natural substances or reused. Also, the proposed material biodegrades into environmentally natural substances. This approach has great potential for practical industrial applications, especially in the light of the “green chemistry” and “circular economy” concepts. Besides, the described materials are a promising base for creating new composite materials for both biodegradable electronics and soft biomedical electronics.
Open Access
Semiconductor film CuBi2O4, modified Pt
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Puzikova, Darya; Dergacheva, Margarita; Khussurova, Gulinur; Leontyeva, Xeniya
Various methods for modifying the surface of semiconductors with platinum nanoparticles are presented in the literature: electrochemical and photoelectrochemical deposition, electrophoretic deposition, photoreduction, chemical deposition, vacuum deposition, atomic layer deposition. At the same time, chemical deposition of Pt, which does not require expensive vacuum and electrochemical equipment, seems to be the least energy-intensive and labor-intensive method. This method consists in applying a solution of H2PtCl6 to the surface of a semiconductor film and subsequent thermal thermal decomposition of this compound to platinum metal at temperatures above 400°C. The chemical deposition method of platinum nanoparticles on the surface of semiconductor CuBi2O4 electrodes by dip-coating from an aqueous solution of 5 mmol/L H2PtCl6 followed by annealing at 450°C is shown. The platinum content in the modified CuBi2O4 film was determined by scanning electron microscopy. It was found that during dip-coating of platinum, the obtained Pt nanoparticles are globules 50–200 nm in size. The deposition of Pt on the surface of CuBi2O4 electrodes leads to an increase in the photocurrent density by 20% (0.3M NaOH solution). Modification of CuBi2O4 electrodes with Pt nanoparticles leads to a decrease in the degradation of the photocurrent from 25% to 3% after 300 s of photopolarization measurements. High values of the quantum efficiency of the photocurrent, reaching 70%, and photoelectrochemical stability make it possible to consider CuBi2O4 electrodes modified with Pt nanoparticles as a promising system for use in photoelectrochemical solar cells and photoelectrochemical decomposition of water.
Open Access
Thickness-Dependent Raman and Photoluminescence Spectra of 2D Indium Selenide
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Nemkayeva, Renata; Guseinov, Nazim; Baigarinova, Gulzhan; Aitzhanov, Madi; Mukhametkarimov, Yerzhan
Recently, III–VI group layered two-dimensional (2D) semiconductors, such as GaS, GaSe, InSe, have considered as promising potential materials for next-generation optoelectronic devices, due to their variable bandgap, high electron mobility, wide photoluminescence (PL) response and ohmic contact [1-3]. In this work, samples of layered indium selenide were synthesized by fusing the corresponding stoichiometric compositions in a vacuum and then thinned down to a nanometer thickness using micromechanical exfoliation. Obtained thin flakes of InSe were placed on SiO2/Si substrates and studied using atomic-force microscopy and Raman spectroscopy. It was found out that the decrease of the thickness down to 4 nm leads to the rise of an additional peak at ~200 cm-1 in Raman spectrum, which is explained by mechanical stress or by the stronger light absorption of thinner InSe flakes. Photoluminescence studies were performed using Raman spectrometer and 473 nm excitation laser. There was revealed a strong dependence of the intensity of PL peak at 510 nm (2.43 eV) on the thickness of the InSe flake. However, single- and bi-layered samples demonstrate neither Raman nor PL signal, possibly due to the fast oxidation without protective coating.
Open Access
Photocell modernization
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Iskakov, Bakhtiyar; Altayqyzy, Marzhan; Tautayev, Yernar; Ongarova, Shynar; Karmenov, Kanat
In our modern world, where science is developing rapidly, it is difficult to determine a specific area of science, which is more promising than the rest. One of the promising areas of science is research aimed at obtaining cheap energy. In the near future, all world reserves of combustible fuel will end: coal, oil, etc., so it remains to develop and study renewable energy sources, such as wind energy, hydropower, solar energy, bioenergy, geothermal energy and, of course, nuclear power. Out of competition, of course, is nuclear power. Despite this, I propose to consider the issue of solar energy. There are minuses and pluses of solar energy. In this article, I propose ways to solve them. The possibilities of using solar energy are limited by a very low energy density, as well as its fluctuations in time, which leads to a huge area of solar radiation collectors and a large material consumption of energy production. For example, in the winter season or at night. A photoelectric effect is the emission of electrons by a substance under the influence of light. The photoelectric effect occurs under the influence of electromagnetic radiation, and electromagnetic radiation is not only photons. Cosmic rays can become a new source for the operation of the solar cell, since they have tremendous energy. A solar cell operating under the influence of cosmic rays will work around the clock, regardless of the seasons. But the main problem is the question of how we will do it. It is known that the flux and energy of cosmic rays are colossal, from several eV to 1020 eV. It is also known that particles passing through the so-called scintillators give a flash, and our idea is to use these flashes for the operation of the photocell. This technique has not yet been studied and is not being studied by all. In the near future, people will learn this technique and we can use solar panels around the clock. The future is for high energy physics.
Open Access
Prospects of application of iron-containing carbon-paste electrode in electrochemical analysis
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Shlyapov, Rustam; Uali, Aitolkyn; Amerkhanova, Shamshiya
The literature analysis devoted to the number of electrochemical sensors developed for metal ions is growing. This is due to the modification of already known classical electronic systems, or the use of new materials in the production of solid-phase, membrane, gas electrodes. One of these systems is a carbon-paste electrode, which belongs to the group of heterogeneous carbon electrodes. The ability to select an electrode-active substance for a specific research task is the main advantage of these electrochemical sensors. For example, an active electrode material was synthesized a polymer metal complex of lead(II) to determine lead ions in a solution [1]. The application of expensive reagents such as ethylene glycol dimethacrylate is the one of the disadvantages of them. Therefore, the purpose of the work was the identifying possibility of application an environmentally friendly natural material for modifying the carbon-paste electrode and determining iron ions in aqueous solutions. The active electrode material (iron-containing carbonized wool) was characterised by modern physical and chemical methods (scanning electron microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), thermal analysis (TG-DTA)). The analytical characteristics of the iron(III)-containing electrode were also determined in the direct potentiometry mode: 1.00·10-4 mol/l was taken, 9.20·10-5 mol/l was found (n = 5, P=0.95, Sx=4.74·10-6), relative error of the determination 8% and during potentiometric titration with a solution of ethylenediamintetraacetic acid in the presence of sulfuric acid (0.001 mol/l): ΔE= 4.4 mV, 1.0 · 10-3 mol/l was taken, 0.95 · 10-3 mol/l was found, Sr=1.92·10-5, n=5, P=0.95, the relative error of the determination 0.2 %. Therefore the amount of iron (II) in aqueous solutions can be determined potentiometrically with a modified carbon-paste electrode.
Open Access
Surface morphology analysis of copper films produced by anodizing process
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Kadir, Meruyert; Alpysbayeva, Balaussa; Smirnov, Vladimir
Currently, copper oxide films are of interest to researchers due to their environmental friendliness, rich resources and low cost. Copper oxide is a p-type semiconductor with a narrow band (1.9 eV-2.2 eV). This material is characterized by the possibility of effective application in sensors [1], hydrogen production [2], energy conversion [3], for the creation of supercapacitors [4], semiconductor catalysis [5], biosensorics [6]. The anodizing process allows you to obtain porous materials based on metal oxides. As with aluminum and titanium oxides, the anodizing process can produce a porous material based on copper oxide. Anodizing is a low-temperature, versatile, economical and simple method. In addition, anodizing allows to change the morphology and size of the copper oxide nanostructure to some extent [7]. In the course of practical work, a copper plate with a size of several microns was used as the initial material. The process of single-stage anodizing was performed at a temperature of 4°C for 90 seconds in an electrolyte of an acidic environment. As a result, the morphology of copper films was studied using Ntegra Therma (NT - MDT) atomic force microscopy. AFM shows that the surface morphology depends on various chemical bonds on the surface of copper.