Activated carbons (ACs) have been the most widespread carbon materials used in supercapacitors (SCs) due to their easy processing methods, good electrical conductivity, and abundant porosity. For the manufacture of electrodes, the obtained activated carbon based on sawdust (karagash and pine) was mixed with conductive carbon and polyvinylidene fluoride as a binder, in ratios of 75% activated carbon, 10% conductive carbon black, and 15% polyvinylidene fluoride (PVDF) in an N-methyl pyrrolidinone solution, to form a slurry and applied to a titanium foil. The total mass of each electrode was limited to vary from 2.0 to 4.0 mg. After that, the electrodes fitted with the separator and electrolyte solution were symmetrically assembled into sandwich-type cell construction. The carbon’s electrochemical properties were evaluated using cyclic voltammetry (CV) and galvanostatic charge–discharge (CGD) studies in a two-electrode cell in 6M KOH. The CV and CGD measurements were realized at different scan rates (5–160 mV s−1) and current densities (0.1–2.0 A g−1) in the potential window of 1 V. ACs from KOH activation showed a high specific capacitance of 202 F g−1 for karagash sawdust and 161 F g−1 for pine sawdust at low mass loading of 1.15 mg cm−2 and scan rate of 5 mV s−1 in cyclic voltammetry test and 193 and 159 F g−1 at a gravimetric current density of 0.1 A g−1 in the galvanostatic charge–discharge test. The specific discharge capacitance is 177 and 131 F g−1 at a current density of 2 A g−1. Even at a relatively high scan rate of 160 mV s−1, a decent specific capacitance of 147 F g−1 and 114 F g−1 was obtained, leading to high energy densities of 26.0 and 22.1 W h kg−1 based on averaged electrode mass. Surface properties and the porous structure of the ACs were studied by scanning electron microscopy, energy-dispersive X-ray analysis, Raman spectroscopy, and the Brunauer–Emmett–Teller method.

In this paper, the diatomite mineral from Mugalzhar field, Aktobe region, has been used as a matrix of catalyst particles to synthesize multiwall carbon nanotubes (MWCNTs) by Catalytic Chemical Vapor Deposition method (CCVD). As a source of carbon was used a propane-butane gas mixture, as a catalyst – Ni particles deposited from Ni(NO3)2 solution during heat treatment process at 400–500 °C. The CCVD method was conducted at a different temperature: 650 °C, 700 °C, 750 °C, 800 °C. Obtained MWCNTs were studied by Raman spectroscopy. The characteristics such as crystallinity, defectiveness, diameter of MWCNTs synthesized at different experimental conditions were evaluated from the positions and intensity ratios of Raman peaks of the samples. The results of investigations of the properties of the obtained carbon nanotubes show the dependence of MWCNTs characteristics on CCVD method temperature. The observation of changes in all the three peaks – D, G and 2D, of obtained materials exhibit, that MWCNTs synthesized at 800 °C possess high crystallinity, low defectiveness and larger diameters as compared with carbon nanotubes grown at 650 °C, 700 °C, 750 °C.

The scales of porous carbon materials usage are constrained by their considerably high cost. Therefore, development of new methods for production of porous carbon with the necessary complex of properties from cheap raw materials is actual. Also, porous carbon materials can be used for growth of carbon nanotubes as a matrices of catalyst particles. Herein, the method of fabrication porous carbon materials from waste of oil industry and their use as a matrices of catalyst particles to growth of CNT was developed. CNTs was synthesized by CVD using as hydrocarbon source - propan-butane gas mixture, as catalyst - Ni particles at 650°C, 700°C, 750°C, 800°C. Obtained carbon materials was investigated by Raman spectroscopy and by scanning electron microscope. Investigations on the properties of the obtained porous materials show soot particles sedimented in pores reduce well nanoparticles of metals from salts which act as nuclei for the growth of multiwall carbon nanotubes during pyrolysis of hydrocarbons by CVD method.

In this work, the effect of acid pre-treatment (hydrochloric acid, HCl) and calcination of diatomite, a silicon dioxide-material from natural sources, was studied with the aim to obtain diatomite-based sorbents with specific physicochemical properties. For this, acid pre-treatments with HCl at different calcination conditions, namely HCl concentration (0.5, 1 M) and calcination temperatures (from 600 to 900 °C) were studied. Morphological features different from those of natural diatomite were obtained. It has been found that treatment of diatomite with 0.5 M HCl at 800 °C showed a specific pore volume of 0.008 cm3/g, and a specific surface area of 19.26 m2/g, while the treatment of diatomite with 1.0 M HCl showed a specific pore volume of 0.011cm3/g, and a specific surface area of 25.57 m2/g. The performance of the acid pretreatment of diatomite for adsorption of Pb ions from water was also studied.

Energy is a fascinating field that has been developing rapidly for many years. Various articles about alternative energy sources, batteries, and supercapacitors are being published today. This article is about the lithium-ion battery. The batteries come with three specific parts, one of which is the anode. In this area, electrons accumulate, which provide power to electrical devices. Since 2011, graphite anodes have been most commonly used in lithium batteries. Silicon is a tempting proposition for scientists working on next-generation lithium batteries with the potential to hold many times more energy than graphite. Silicon is a promising material for the anodes of lithium-ion batteries of a new generation since, in the process of electrochemical introduction, it can accumulate a large amount of lithium (up to 4.4 Li atoms per Si atom) and provide very high values of specific capacity (4200 mAh/g). The present article overviews the prospects for using diatomaceous earth (DE) (from the Mugalzhar region) in the continuous expansion of energy science and technology. Environmentally friendly silicon dioxide and silicon production, diatomaceous earth has the necessary nano-microstructure, which offers the advantages inherent in existing and new applications in electrochemistry, catalysis, optoelectronics, and biomedical engineering. Silicon, silicon, and silicon-based materials are useful for energy storage and storage applications. Also, for comparison, the surface of the DE was modified with nanotubes. The electrode material has been characterized by EDAX, SEM, BET, and electrochemical techniquesс. The results obtained showed the advantage of modified diatomite (specific surface area – 188.9 m2/g and particular capacity of the battery – 120 mA⋅h⋅g–1) compared to unmodified (specific surface area – 39.1 m2/g and a particular degree of the battery – 100 mA⋅h⋅g –1).