TWO-STAGE HEAT TREATMENT FOR PRODUCING HIGHLY CRYSTALLINE h-BN NANOPARTICLES FROM BORIC ACID AND UREA

Authors

Sherzod E. ABDURAKHMONOV, Tashkent Institute of Chemical Technology, Tashkent, Uzbekistan;Almalyk branch of the National Research Technological University "MISiS", Almalyk, UzbekistanFollow
Mastura Kh. ARIPOVA, Tashkent Institute of Chemical Technology, Tashkent, UzbekistanFollow
Umar A. YAKHYAEV, Tashkent Institute of Chemical Technology, Tashkent, UzbekistanFollow
Shoxrux B. NAIMOV, Tashkent Institute of Chemical Technology, Tashkent, UzbekistanFollow
Odiljon E. ABDURAKHMONOV, Tashkent Institute of Chemical Technology, Tashkent, UzbekistanFollow

Abstract

The purpose of the study was to investigate the formation of the crystal structure of hexagonal boron nitride (h-BN) nanoparticles obtained by the chemical-thermal method using two-stage heat treatment. Boric acid and urea were used as starting precursors, enabling ammonia-free synthesis conditions. It is shown that the first thermal stage at 600 °C under a nitrogen atmosphere leads to the formation of a predominantly amorphous BN-containing precursor, whereas the second stage at 1000 °C in an N₂/H₂ atmosphere promotes crystallization of a highly ordered hexagonal h-BN phase. The morphology and particle size distribution were examined by transmission electron microscopy, while the phase composition and crystal structure were analyzed by X-ray diffraction followed by Rietveld refinement. The obtained h-BN nanoparticles exhibit a narrow size distribution of 2–10 nm and a high degree of crystallinity (up to ~99%). Structural modeling and electron density analysis performed using the VESTA software confirm the formation of a layered hexagonal h-BN lattice with an interplanar spacing of approximately 3.3 Å. The results highlight the critical role of the two-stage thermal treatment and gas atmosphere in controlling the crystallinity and structural ordering of h-BN nanoparticles.

Recommended Citation

ABDURAKHMONOV, Sherzod E.; ARIPOVA, Mastura Kh.; YAKHYAEV, Umar A.; NAIMOV, Shoxrux B.; and ABDURAKHMONOV, Odiljon E. (2026) "TWO-STAGE HEAT TREATMENT FOR PRODUCING HIGHLY CRYSTALLINE h-BN NANOPARTICLES FROM BORIC ACID AND UREA," CHEMISTRY AND CHEMICAL ENGINEERING: Vol. 2026: No. 1, Article 2.
DOI: https://doi.org/10.70189/1992-9498.1711
Available at: https://cce.researchcommons.org/journal/vol2026/iss1/2