Chemical Bulletin of Kazakh National University

Variations in the distribution of trace elements in pyrrhotite Fe1-xS depending on the parameters of mechanical homogenization

2025-01-15T09:02:44+00:00

This paper presents the results of the synthesis of sulfide standards based on the Fe_0.91S pyrrhotite matrix, including 24 elements (Co, Ni, Cu, Zn, As, Se, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, W, Re, Os, Ir, Pt, Au, Pb, Bi) intended for use in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The main attention is paid to the study of the influence of such parameters as the duration of mechanical milling, the laser beam diameter during measurements and the initial concentrations of impurities on the distribution of trace elements in the material. As a result, it was found that with 120 minutes of milling in combination with a laser beam of 80 μm diameter, it is possible to achieve relative standard deviation (RSD) values of 10%, which corresponds to the recommendations for most elements. At high impurity concentrations, the RSD values for most elements are lower, but the material becomes more heterogeneous. At the same time, at lower concentrations, an improvement in the homogeneity of the composition is observed. The data obtained demonstrates the effectiveness of mechanical homogenization for improving analytical accuracy and reproducibility, which makes such standards promising for the analysis of complex sulfide materials in geochemistry and materials science.

Evaluation of perspectives for the synthesis of Ti3AlC2 in Kazakhstan for supercapacitor application

2025-01-15T09:02:53+00:00

With the increasing demand for energy-efficient technologies, there is a growing focus on developing new materials for supercapacitors and other energy devices. MXene Ti₃C₂T_x is known for its unique electrochemical properties and has garnered significant interest in such applications. However, the high cost of synthesizing MXene limits its commercial viability, prompting research into cost-effective methods for synthesizing the MXene precursor, the Ti₃AlC₃ MAX phase. This paper presents a method for synthesizing the MAX-phase Ti₃AlC₂ using local raw materials from Kazakhstan Electrolysis Plant JSC and Ust-Kamenogorsk Titanium-Magnesium Plant JSC. Utilizing local resources significantly reduces production costs. The study investigates the impact of temperature conditions and excess aluminum content on MAX phase formation. Process optimization, including pressing the precursors and coating them with a layer of aluminum oxide, resulted in a Ti₃AlC₂ content of 91.2%. MXene Ti₃C₂T_x derived from the synthesized MAX phase demonstrated electrochemical performance comparable to materials prepared from commercially available MAX phases. An economic assessment revealed that the cost of synthesizing 1 gram of Ti₃AlC₂ from local precursors is $0.22, more than 19 times lower than similar commercial materials. These findings confirm the cost-effectiveness and competitiveness of the proposed approach, highlighting its potential to create high-performance materials suitable for advanced batteries, supercapacitors, and other energy devices.

Comparative characteristics of microcrystalline cellulose obtained from the rice waste production of Kazakhstan

2025-01-15T09:03:02+00:00

Development of methods for effective processing of reconstructive biological resources and allocation of valuable materials refers to the main tasks of science and industry. The work determines the optimal hydro module and physico-chemical properties of microcrystalline cellulose (MCC), obtained by the method of organosolvent oxidation of rice husk (RH), grown in the southern (Kyzylorda region) and southeast (Almaty region) of Kazakhstan, and it was established that the yield and the qualitative indicators of the MCC depends on the climatic and geographical features of the region, where raw materials are grown to obtain cellulose. The effective hydro module for MCC obtained from Bakanas rice husk (B-RH) was found to be 1:12 g/mL and yield was 45.0%, whereas Kyzylorda rice husk (K-RH) the effective hydromodule was 1:10 g/mL and yield found to be equal to 52.58%. During organosolvent oxidation, the selected method did not require additional processing of raw materials. It was discovered that for delignification, it takes 120 minutes of time, and the yield of MCC will be 15-18% higher than the cellulose obtained by the alkali. Rice husk is a promising alternative raw material for cellulose production and the use of the organosolvent method for obtaining an MCC is an economically advantageous and environmentally friendly method.