Azamat Urkunbay

Mr. Azamat Urkunbay


Research Focus & Metrics

Academic Career Length

2Years (2025-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 June 2025 in Crystals
Verified
Journal Article
Open access
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YKYernat Kozhakhmetov
Yernat Kozhakhmetov
SKSherzod Kurbanbekov
Sherzod Kurbanbekov
NMNuriya Mukhamedova
Nuriya Mukhamedova
AUAzamat Urkunbay
Azamat Urkunbay
AKAibar Kizatov
Aibar Kizatov
DBDilnoza Baltabayeva
Dilnoza Baltabayeva
Due to the depletion of hydrocarbon resources worldwide, intensive research is being conducted to identify alternative energy carriers. Hydrogen has emerged as a promising candidate due to its high energy density and environmentally friendly nature. However, large-scale implementation of hydrogen energy is hindered by the lack of safe, efficient, and cost-effective storage methods. Among the various materials studied for solid-state hydrogen storage, boron nitride (BN)-based compounds have attracted significant attention owing to their high thermal stability, tunable morphology, and potential for physisorption-based storage. This review focuses on recent advances in the synthesis, functionalization, and structural optimization of BN-based materials, including nanotubes, nanosheets, porous frameworks, and chemically modified BN. Although other boron-containing hydrides such as LiBH4, Mg(BH4)2, and closo-borates are briefly mentioned for comparison, the primary emphasis is placed on BN-related systems. This paper discusses various modification strategies aimed at enhancing hydrogen uptake and reversibility, offering insights into the future potential of BN-based materials in hydrogen storage technologies.

10 February 2025 in Crystals
Verified
Journal Article
Open access
PDF file
YKYernat Kozhakhmetov
Yernat Kozhakhmetov
YTYERKEZHAN TABIYEVA
YERKEZHAN TABIYEVA
NMNuriya Mukhamedova
Nuriya Mukhamedova
AUAzamat Urkunbay
Azamat Urkunbay
MAMadina Aidarova
Madina Aidarova
ESElfira Sagymbekova
Elfira Sagymbekova
This study is focused on the sorption properties and the changes in the structure and state of Ti-25Al-25Nb (at.%) system alloys under thermal cyclic loading. These samples were produced by combining high-energy processing methods through mechanization and spark plasma sintering in the temperature range of 1100–1300 °C, followed by two-stage heat treatment at temperatures of 800 °C and 1250 °C. Thermal cyclic experiments on hydrogen sorption/desorption with samples of the Ti-25Al-25Nb (at.%) system were conducted at the VIKA experimental installation at a saturation temperature of about 500 °C and a degassing temperature of 610 °C. It took about 41 min to reach pressure equilibrium at 500 °C. The hydrogen diffusion coefficient was calculated based on the Barrer formula and was 9.1 × 10−5 cm2/s at 500 °C. The maximum hydrogen content was recorded after the first sorption/desorption cycle and was 1.91 wt%. Due to the multiple thermal cyclic effects in the hydrogen medium, the predominantly two-phase (O + B2) alloy structure underwent transformation to form a new structure (O-AlNbTi2). In the phase composition of the Ti-25Al-25Nb (at.%) alloy, the formation of hydrides in the form of independent phases as a result of thermal cycling was not detected. Hydrogen absorption is most likely to be associated with the formation of an interstitial solution based on existing crystalline phases.