Қазақ ұлттық қыздар педагогикалық университеті / Казахский национальный женский педагогический университет

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Acid Modification of Diatomite-Based Sorbents
(2020-09-30)
Araylim Nurgain
;
Meruyert Nazhipkyzy
;
Aizhan A. Zhaparova
;
Almagul Issanbekova
;
Michela Alfè
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.
Цитирования (OpenAlex) 8Цитирования (OpenCitations) 6
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Humic Acid Modified Applied Palladium Catalysts for Nitro Compounds Reduction
(2023-01-01)
Индира Мухаметкеримовна Джелдыбаева
;
Zhaksyntay K. Kairbekov
;
Manshuk Z. Esenalieva
;
Altay Zh. Kairbekov
;
S.M. Suimbayeva
This work studies the possibility of using humic acids (HA) as a natural polymer-modifier for applied palladium catalysts.New catalysts based on palladium -HA fixed on the carrier bauxite-094 (B-094) have been synthesized and their catalytic properties in the process of reducing p-nitrodiethylaniline (PNDA) and potassium o-nitrophinolate (PtONPh) have been studied.Humic acid is a non-toxic, inexpensive, easily accessible high molecular weight polymer.Therefore, its use as a modifier polymer for applied palladium catalysts in the processes of hydrogenation of nitro compounds is very cost-effective and relevant as of today.This work presents the results of studies on different methods for the preparation of polymer metal catalysts.It has been shown that HA has stronger acid and sorption properties, greater branching and asymmetry of macromolecules.It has been established that the activity and stability of polymer-metallic complexes (PMC) based catalysts depend on the sequence of application of the active phase on the carrier.The largest specific surface area is characterized by the catalyst 1.0% Pd-HA (1.0%)/B-094, which exhibits the greatest activity and stability in the reduction reactions of PNDA and PtONPh.Considering that HA (polymer) and bauxite-094 (carrier) are materials of natural origin, the development of such catalysts is not accompanied by large economic costs, which is one of the main requirements for modern catalysts.
Цитирования (OpenAlex) 4Цитирования (OpenCitations) 3
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Production and optimization of activated carbon from plant waste with high specific surface area for moisture-saving applications in agriculture
(2024-10-20)
Yerlan Doszhanov
;
Aitugan Sabitov
;
Karina Saurykova
;
Zulkhair Aimukhametovich Mansurov
;
М С Курманбаева
In conditions of water shortage, sustainable agricultural development requires the use of water-saving technologies, including the use of water-retaining substrates based on activated carbon. In this work, the textural and adsorption characteristics of activated carbon obtained from plant waste were studied at different mass ratios of the sorbent and KOH (1:1, 1:2, 1:3 and 1:4). The aim of the study was to determine the optimal activation conditions for creating a material with a high specific surface area and a developed porous structure. The results showed that the largest pore volume (1.6 cm3/g) and a high degree of microporosity are achieved at a ratio of 1:3, which is confirmed by the analysis of pore distribution using the DFT and BJH methods. FTIR spectroscopy revealed the presence of functional groups (O–H, C=O and C–O) that contribute to water conservation. The differential pore volume distribution (dv(r), cm3/Å/g) also demonstrated that at a ratio of sorbent and KOH (1:3), the sample structure optimally combines micropores and mesopores, which increases the adsorption capacity of carbon.
Цитирования (OpenAlex) 1
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The Significant Role Of Mxene’s Derivatives And Composites In Supercapcitors: A Review
(2025-01-01)
Meruyert Nazhipkyzy
;
Aknur Berkinbayeva
;
Muhammad Hashami
;
Zhanar Kudyarova
;
Togzhan Mashan
MXene derivatives and composites are becoming fresh and promising two-dimensional (2D) materials because of their unique properties, performance, and multifunctionalities.This review covers the general aspects of MXenes (family of 2D transition metal carbides, nitrides, and carbonitrides), their MAX phase (a diverse class of nanolaminate materials with intriguing properties that have received incredible global research attention because they bridge the divide separating metals and ceramics.)precursors, dissimilarities and similarities between MAX phases and MXenes, and special properties of both materials.The important focuses are made on the methods of MXene synthesis and their stability and conductivity, as well as on synthesizing new MXene composites with desired characteristics.The impacts of MXenes in energy storage systems, especially supercapacitors, are discussed based on the high specific surface area, tunable porosity, and optimized inter-layer spacing.Here, various aspects of MXene materials, including properties, synthesis, and applications, have been discussed to highlight their importance for the development of energy storage systems and material science research.
Цитирования (OpenAlex) 4Цитирования (OpenCitations) 1
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Synthesis of Biomass-Derived Graphene Nanomaterials by Chemical Activation with KOH
(Multidisciplinary Digital Publishing Institute, 2025-11-21)
Makpal Seitzhanova
;
Zhanar B. Kudyarova
;
Bibigul B. Rakhimova
;
Lyaila Tugelbayeva
;
Жандос Турегулович Тауанов
This work introduces an environmentally sustainable and cost-effective strategy for synthesizing graphene nanomaterials from agricultural residues—walnut shells and apricot stones. The synthesis pathway combines desilication, controlled pre-carbonization, chemical activation with KOH, and mild exfoliation to produce few-layer graphene with a high degree of structural order. The process, conducted at 523–573 K for pre-carbonization and 1123 K for activation, enables the formation of graphene sheets with a specific surface area of approximately 1300 m2/g, carbon content of 80–90%, and average pore diameter below 100 nm. The materials were comprehensively characterized using SEM, TEM, Raman spectroscopy, and BET analysis. Raman spectra revealed an IG/I2D ratio of ~1.5–2 a.u., confirming the presence of 4–5 graphene layers. Compared to conventional biomass-derived graphene routes, the developed approach ensures enhanced porosity, higher graphitic ordering, and improved purity, demonstrating its strong potential for energy storage, adsorptive purification, and environmentally benign nanotechnology applications.
Цитирования (OpenAlex) 8Цитирования (OpenCitations) 1
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Comparative Study of the Structural and Adsorptive Performance of Biomass-Derived Graphene Materials
(Multidisciplinary Digital Publishing Institute, 2026-02-08)
Makpal Seitzhanova
;
Zhanar Kudyarova
;
Yerlan Doszhanov
;
Bibigul B. Rakhimova
;
Svetlana Aleshkova
This study presents the development of an environmentally benign and economically viable methodology for the synthesis of graphene-containing carbon materials derived from renewable agricultural residues, specifically walnut shells, rice husks, and apricot stones. The proposed synthesis route involves sequential stages of controlled pre-carbonization, desilicification, chemical activation with potassium hydroxide (KOH), and subsequent mild exfoliation, resulting in the formation of few-layer graphene with a high degree of structural ordering. Pre-carbonization carried out at 523–573 K, followed by activation at 1123 K, yields graphene sheets exhibiting a specific surface area of 1300–1800 m2/g, a carbon content of 60–90%, and an average pore diameter below 100 nm. The synthesized materials were subjected to comprehensive physicochemical characterization using BET surface area analysis, Raman spectroscopy, FTIR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic absorption flame emission spectrophotometry. Raman spectroscopic analysis revealed an I_G/I_2D intensity ratio of approximately 1.5–2.0, indicating the presence of graphene structures consisting of approximately four to five layers. To enhance adsorption performance, the graphene-containing carbon materials were further functionalized with sulfuric acid, and the successful incorporation of surface functional groups was confirmed by FTIR spectroscopy. The adsorption properties of the functionalized graphene-containing carbon materials were evaluated in aqueous solutions containing sodium, potassium, calcium, and magnesium salts, demonstrating adsorption efficiencies of up to 80%. Compared to conventional biomass-derived graphene synthesis methods, the developed approach produces materials with enhanced porosity, higher graphitic ordering, and improved chemical purity. These characteristics highlight the strong potential of the synthesized graphene-containing carbon materials for applications in energy storage systems, adsorption-based water purification technologies, and environmentally sustainable nanotechnological applications.
Цитирования (OpenAlex) 4
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Impact of Zeolites on Growth Dynamics of Medicago sativa and Lactuca sativa in Hydroponics
(Multidisciplinary Digital Publishing Institute, 2026-02-28)
Yerlan Doszhanov
;
Dana Akhmetzhanova
;
Leticia Fernández Velasco
;
Korlan Khamitova
;
Arman Zhumazhanov
In Kazakhstan, food safety is a pressing issue due to water and soil pollution. This study examined the effect of natural zeolite as an alternative hydroponic substrate on the physicochemical properties of the medium and the physiological and metabolic responses of two agricultural crops: Medicago sativa L. and Lactuca sativa L. BET analysis revealed that the zeolite possesses a substancial specific surface area (22 m²/g), ensuring effective moisture retention and gradual nutrient release. After plant cultivation, these parameters decreased moderately, confirming the filling of the pores with organic compounds without loss of key properties. In experiments with Medicago sativa, zeolite provided better aeration and stable moisture, promoting the development of a branched root system and increased seedling viability compared to an artificial substrate. Metabolic analysis of three Lactuca sativa varieties revealed cultivar-specific adaptive responses. Zeolite increased the synthesis of fatty acids and their derivatives, reflecting membrane-protective restructuring, while sugar and terpenoid content varied depending on the variety. The results confirm the suitability of zeolite as a stable substrate for hydroponic production, allowing for optimized water consumption, improved root development, and enhanced physiological stability of plants.
Цитирования (OpenAlex) 2

Қазақ ұлттық қыздар педагогикалық университеті / Казахский национальный женский педагогический университет

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