Natalya Khan
@kaznu.kz
Department of General and Inorganic Chemistry, Faculty of Chemistry and Chemical Technology
Al-Farabi Kazakh National University
RESEARCH INTERESTS
Inorganic chemistry, mechanochemistry, photocatalysis, nanotechnology
Scopus Publications
Scopus Publications
Aizhan Rakhmanova, Baktiyar Soltabayev, Ahmad Ajjaq, Natalya Khan, Sandugash Kalybekkyzy, Selim Acar, and Almagul Mentbayeva
Elsevier BV
Aizhan Rakhmanova, Baktiyar Soltabayev, Ahmad Ajjaq, Natalya Khan, Sandugash Kalybekkyzy, Selim Acar, and Almagul Mentbayeva
Elsevier BV
Zhandos Shalabayev, Abylay Abilkhan, Natalya Khan, Saparbek Tugelbay, Anar Seisembekova, Batukhan Tatykayev, and Matej Balaz
MDPI AG
In the present study, a green, scalable, and environmentally friendly approach was developed for the fabrication of Bi2S3-decorated CdS nanoparticles with an efficient hydrogen generation ability from the water. As a sulfur source, thiourea was used. The process was completed in two stages: mechanical activation and thermal annealing. The presence of spherical CdS nanoparticles and Bi2S3 nanorods in the CdS/Bi2S3 nanocomposite was confirmed and proved by XRD, Raman spectroscopy, SEM-EDS, and TEM. The synthesized CdS/Bi2S3 nanocomposites were evaluated for their photocatalytic hydrogen evolution capabilities. The CdS/Bi2S3 photocatalyst exhibited 25% higher photocatalytic activity compared to CdS, reaching a hydrogen evolution rate of 996.68 μmol h−1g−1 (AQE 0.87%) after 3.5 h under solar-light irradiation.
Natalya Khan, Gairat Burashev, Ayaulym Kadylbekova, Timur Sh. Atabaev, Zhumabay Bakenov, Fail Sultanov, Almagul Mentbayeva, and Batukhan Tatykayev
Elsevier BV
Gairat Burashev, Batukhan Tatykayev, Matej Baláž, Natalya Khan, Ardak Jumagazieva, Zhanar Iskakbayeva, Anar Seysembekova, Saparbek Tugelbay, Nurshat Turgynbay, Almagul Niyazbayeva,et al.
IOP Publishing
Abstract In this work, we have developed a facile, dry, and environmentally friendly mechanochemical method for the synthesis of cadmium sulfide (m-CdS) nanoparticles in a planetary ball mill using non-toxic precursors. Thiourea was for the first time used as a precursor of sulfide ion in room temperature solid state ball milling synthesis. For comparison of the mechanochemical approach with others, cadmium sulfide nanoparticles were also prepared using the solvothermal method (s-CdS). The crystal structure of cadmium sulfide nanoparticles was studied by XRD, the qualitative chemical band properties were examined by Raman scattering and x-ray photoelectron spectroscopy analysis, and particle morphology and microstructure were investigated by scanning electron microscopy and transmission electron microscopy methods. The sizes of the m-CdS nanoparticles had 5–6 nm in diameter, which is 10 times smaller than the diameter of s-CdS nanorods. The photocatalytic activities of as-prepared cadmium sulfide nanoparticles on the dye degradation and hydrogen production by water splitting were evaluated and the antibacterial activities were also tested. The photocatalytic activity of m-CdS was superior to that of s-CdS in the degradation of Orange II under visible light irradiation. Better results for m-CdS were also evidenced in photocatalytic experiments on hydrogen generation. The maximum rate of hydrogen evolution for m-CdS was 191.9 µmolg−1h−1 at the 120th min,while this indicator for s-CdS was only 58.0 µmolg−1h−1 at the same irradiation time.The better effect of m-CdS was evidenced also in an antibacterial study (namely against gram-positive bacteria).
G. Burashev, B. Tatykayev, M. Baláž, N. Khan, A. Seysembekova, S. Tugelbay, N. Turgynbay, M. Burkitbayev, and Zh. Shalabayev
al-Farabi Kazakh National University
Herein a systematic study of two-step solid-phase synthesis of CdS@ZnS nanocomposites and their photocatalytic activity is presented. First, CdS nanoparticles were synthesized in a planetary ball mill through a solid-state ion exchange reaction. In the second step, Cd2+ ions were partially replaced by Zn2+ ions at the surface of the nanoparticles using solvent free long-term activation in a high-energy planetary ball mill. The optimal activation time in a ball mill was determined to be 45 min. Spherical CdS nanoparticles with a diameter of 10 nm and modified CdS@ZnS (45 min) nanocomposites were characterized by X-ray diffraction analysis, Raman and UV-vis spectroscopy, and scanning electron microscopy. The ability of nanocomposites for photocatalytic water purification was tested on the degradation of the model organic dye Orange II in an aqueous solution under the visible light irradation. The modified CdS@ZnS nanocomposites showed higher photocatalytic activity compared to the original CdS nanoparticles.
Aiganym Oskenbay, Daniyar Salikhov, Oleg Rofman, Islam Rakhimbek, Zhandos Shalabayev, Natalya Khan, Baktiyar Soltabayev, Almаgul Mentbayeva, Matej Baláž, and Batukhan Tatykayev
Elsevier BV
Farit Kh. Urakaev, Natalya V. Khan, Almagul I. Niyazbayeva, Dinar N. Zharlykasimova, and Mukhambetkali M. Burkitbayev
Ural Federal University
The task of this article is to update, develop and introduce into scientific practice the method of "mechanochemical recrystallization" in solid-phase systems with small additives of the liquid phase of the solvent and solid-phase precursors to stabilize the formed nanoparticles. The essence of this method is shown using the example of mechanical activation of the S–AgNO3–NH4X system, where X = Cl, Br, I, with the addition of dimethyl sulfoxide (DMSO), and the resulting mechanochemical synthesis of sulfur-containing nanocomposites S/AgX with the controlled content of sulfur nanoparticles (nanosulfur). The predetermined content of nanosulfur in nanocomposites is ensured by a continuous process of dissolution-crystallization (recrystallization) of starting sulfur in the DMSO medium in a mechanochemical reactor. The proposed technical solution made it possible to obtain S/AgX nanocomposites by a single mechanical treatment of powder precursors – AgNO3, NH4Х, NH4NO3 (diluent), commercial sulfur and DMSO in planetary ball mills with various milling tools. The method also includes washing the water-soluble components of mechanosynthesis.
F.Kh. Urakaev, M.M. Burkitbayev, and N.V. Khan
al-Farabi Kazakh National University
For the first time a sulfur solution in dimethyl sulfoxide (DMSO) with concentration of 1.592 g/L [1] was used to prepare sulfur nanoparticles (nanosulfur). Synthesis and stabilization of colloidal sulfur particles was carried out at 298K (25°C) by diluting the sulfur solution in DMSO with water 10 to 1000 times. The stable sizes of nanosulfur measured by dynamic light scattering were ~ 100 nm. The results were confirmed both qualitatively and quantitatively using X-ray and electron microscopy methods. The antibacterial activity of the nanosulfur on the phytopathogenic bacterium Erwinia amylovora and fungus Fusarium solani was tested.
Natalya Khan, Matej Baláž, Mukhambetkali Burkitbayev, Batukhan Tatykayev, Zhandos Shalabayev, Renata Nemkayeva, Ardak Jumagaziyeva, Almagul Niyazbayeva, Islam Rakhimbek, Askhat Beldeubayev,et al.
Elsevier BV
N.V. Khan, M. Baláž, M.M. Burkitbayev, B.B. Tatykayev, Zh.S. Shalabayev, A.I. Niyazbayeva, and F.Kh. Urakaev
al-Farabi Kazakh National University
S/AgI microstructures were produced by solvothermal DMSO-mediated synthesis using two methods of sulfur precipitation: at room temperature (method 1) and by water (method 2). The samples were obtained with different percentages of AgI: 10, 30 and 50 %. Microstructures were investigated with help of XRD, Raman spectroscopy and SEM/EDS (elemental mapping). XRD and Raman spectroscopy confirmed the presence of sulfur and AgI. EDS elemental mapping revealed that samples were composed of large grains of sulfur covered by smaller grains of AgI. The obtained SEM micrographs revealed that the 1st method gave larger grains of sulfur in comparison with the 2nd method. Testing of the microstructures as photocatalysits showed the low activity; as the prepared samples were able to degrade no more than 7 % of the molecules of Orange II. Significant biological activity was detected only for S/AgI (2) 50 % sample, as it was able to suppress test strains of S. aureus ATCC ВАА-39, P.aeruginosa ATCC 9027 and Erwinia amylovora at MBC/MFC 5000 µg/mL, and E. coli ATCC 8739 at 2500 µg/mL.
Zhandos Shalabayev, Matej Baláž, Natalya Khan, Yelmira Nurlan, Adrian Augustyniak, Nina Daneu, Batukhan Tatykayev, Erika Dutková, Gairat Burashev, Mariano Casas-Luna,et al.
MDPI AG
CdS nanoparticles were successfully synthesized using cadmium acetate and sodium sulfide as Cd and S precursors, respectively. The effect of using sodium thiosulfate as an additional sulfur precursor was also investigated (combined milling). The samples were characterized by XRD, Raman spectroscopy, XPS, UV-Vis spectroscopy, PL spectroscopy, DLS, and TEM. Photocatalytic activities of both CdS samples were compared. The photocatalytic activity of CdS, which is produced by combined milling, was superior to that of CdS, and was obtained by an acetate route in the degradation of Orange II under visible light irradiation. Better results for CdS prepared using a combined approach were also evidenced in photocatalytic experiments on hydrogen generation. The antibacterial potential of mechanochemically prepared CdS nanocrystals was also tested on reference strains of E. coli and S. aureus. Susceptibility tests included a 24-h toxicity test, a disk diffusion assay, and respiration monitoring. Bacterial growth was not completely inhibited by the presence of neither nanomaterial in the growth environment. However, the experiments have confirmed that the nanoparticles have some capability to inhibit bacterial growth during the logarithmic growth phase, with a more substantial effect coming from CdS nanoparticles prepared in the absence of sodium thiosulfate. The present research demonstrated the solvent-free, facile, and sustainable character of mechanochemical synthesis to produce semiconductor nanocrystals with multidisciplinary application.
F. Kh. Urakaev, N. V. Khan, Zh. S. Shalabaev, B. B. Tatykaev, R. K. Nadirov, and M. M. Burkitbaev
Pleiades Publishing Ltd
N V Khan, M M Burkitbayev, and F Kh Urakaev
IOP Publishing
Abstract In this research work described synthesis of nanocomposites in the systems S–AgI and S–Ag2S–AgI in dimethyl sulfoxide (DMSO, (CH3)2SO) medium, and its some properties. Nanocomposites were obtained through the solvothermal synthesis at temperature range (T) 25÷160°C. The initial solutions were prepared by dissolution of sulfur (S), silver nitrate (AgNO3 ) and ammonium iodine (NH4I) in DMSO. The final products were obtained through the simple exchange reactions between initial solutions. Using the X-ray phase analysis (XRD), energy dispersive X-ray analysis (EDAX) and scanning electron microscopy (SEM) the samples were tested on phase and elemental composition, particle size and morphology, respectively. The results of XRD revealed that nanocomposites represented by S and AgI for system S–AgI, and by S, AgI and Ag2S for S–Ag2S–AgI system. The EDAX analysis showed the presence in composition of the investigated samples such elements like S, Ag and I for both systems. The SEM images demonstrated that both systems have a heterogeneus structure, the particles represented by flat and irregular shape. The size of the particles for S–AgI is fluctuated from 100 to 50000 nm and for S–Ag2S–AgI – from 90 to 4000 nm.
Tlek Ketegenov, Olesya Tyumentseva, Natasha Khan, Ardak Karagulanova, and Markizat Myrzabekova
Elsevier BV