Denis Nazarov

Dr. Denis Nazarov

Research Park of Saint Petersburg State University, 198504 Saint Petersburg, Russia
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Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

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

Representative Publications

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3 May 2019 in Coatings
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YKYury Koshtyal
Yury Koshtyal
Denis NazarovDenis Nazarov
Denis Nazarov
IEIlya Ezhov
Ilya Ezhov
IMIlya Mitrofanov
Ilya Mitrofanov
AKArtem Kim
Artem Kim
Maxim MaximovMaxim Maximov
Maxim Maximov
Atomic layer deposition (ALD) provides a promising route for depositing uniform thin-film electrodes for Li-ion batteries. In this work, bis(methylcyclopentadienyl) nickel(II) (Ni(MeCp)2) and bis(cyclopentadienyl) nickel(II) (NiCp2) were used as precursors for NiO ALD. Oxygen plasma was used as a counter-reactant. The films were studied by spectroscopic ellipsometry, scanning electron microscopy, atomic force microscopy, X-ray diffraction, X-ray reflectometry, and X-ray photoelectron spectroscopy. The results show that the optimal temperature for the deposition for NiCp2 was 200–300 °C, but the optimal Ni(MeCp)2 growth per ALD cycle was 0.011–0.012 nm for both precursors at 250–300 °C. The films deposited using NiCp2 and oxygen plasma at 300 °C using optimal ALD condition consisted mainly of stoichiometric polycrystalline NiO with high density (6.6 g/cm3) and low roughness (0.34 nm). However, the films contain carbon impurities. The NiO films (thickness 28–30 nm) deposited on stainless steel showed a specific capacity above 1300 mAh/g, which is significantly more than the theoretical capacity of bulk NiO (718 mAh/g) because it includes the capacity of the NiO film and the pseudo-capacity of the gel-like solid electrolyte interface film. The presence of pseudo-capacity and its increase during cycling is discussed based on a detailed analysis of cyclic voltammograms and charge–discharge curves (U(C)).

13 January 2017 in Nanomaterials
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Denis NazarovDenis Nazarov
Denis Nazarov
EZElena Zemtsova
Elena Zemtsova
ASAlexandr Yu. Solokhin
Alexandr Yu. Solokhin
Ruslan ValievRuslan Valiev
Ruslan Valiev
VSVladimir Smirnov
Vladimir Smirnov
In this study, we present the detailed investigation of the influence of the etching medium (acidic or basic Piranha solutions) and the etching time on the morphology and surface relief of ultrafine grained (UFG) and coarse grained (CG) titanium. The surface relief and morphology have been studied by means of scanning electron microscopy (SEM), atomic force microscopy (AFM), and the spectral ellipsometry. The composition of the samples has been determined by X-ray fluorescence analysis (XRF) and X-ray Photoelectron Spectroscopy (XPS). Significant difference in the etching behavior of UFG and CG titanium has been found. UFG titanium exhibits higher etching activity independently of the etching medium. Formed structures possess higher homogeneity. The variation of the etching medium and time leads to micro-, nano-, or hierarchical micro/nanostructures on the surface. Significant difference has been found between surface composition for UFG titanium etched in basic and acidic Piranha solution. Based on the experimental data, the possible reasons and mechanisms are considered for the formation of nano- and microstructures. The prospects of etched UFG titanium as the material for implants are discussed.

8 May 2020 in Energies
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Maxim MaximovMaxim Maximov
Maxim Maximov
Denis NazarovDenis Nazarov
Denis Nazarov
ARAleksander Rumyantsev
Aleksander Rumyantsev
YKYury Koshtyal
Yury Koshtyal
IEIlya Ezhov
Ilya Ezhov
APAnatoly Popovich
Anatoly Popovich
Lithium nickelate (LiNiO2) and materials based on it are attractive positive electrode materials for lithium-ion batteries, owing to their large capacity. In this paper, the results of atomic layer deposition (ALD) of lithium–nickel–silicon oxide thin films using lithium hexamethyldisilazide (LiHMDS) and bis(cyclopentadienyl) nickel (II) (NiCp2) as precursors and remote oxygen plasma as a counter-reagent are reported. Two approaches were studied: ALD using supercycles and ALD of the multilayered structure of lithium oxide, lithium nickel oxide, and nickel oxides followed by annealing. The prepared films were studied by scanning electron microscopy, spectral ellipsometry, X-ray diffraction, X-ray reflectivity, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and selected-area electron diffraction. The pulse ratio of LiHMDS/Ni(Cp)2 precursors in one supercycle ranged from 1/1 to 1/10. Silicon was observed in the deposited films, and after annealing, crystalline Li2SiO3 and Li2Si2O5 were formed at 800 °C. Annealing of the multilayered sample caused the partial formation of LiNiO2. The obtained cathode materials possessed electrochemical activity comparable with the results for other thin-film cathodes.

26 July 2018 in ACS Biomaterials Science & Engineering
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Denis NazarovDenis Nazarov
Denis Nazarov
VSVladimir M. Smirnov
Vladimir M. Smirnov
EZElena G. Zemtsova
Elena G. Zemtsova
NYNatalia Mikhailovna Yudintceva
Natalia Mikhailovna Yudintceva
MSMaxim A. Shevtsov
Maxim A. Shevtsov
Ruslan ValievRuslan Valiev
Ruslan Valiev

Verified
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Denis NazarovDenis Nazarov
Denis Nazarov
IEIlya Ezhov
Ilya Ezhov
NYNatalia Mikhailovna Yudintceva
Natalia Mikhailovna Yudintceva
Maxim ShevtsovMaxim Shevtsov
Maxim Shevtsov
Aida RudakovaAida Rudakova
Aida Rudakova
Maxim MaximovMaxim Maximov
Maxim Maximov
The combination of titania nanofilms and silver nanoparticles (NPs) is a very promising material, with antibacterial and osseointegration-induced properties for titanium implant coatings. In this work, we successfully prepared TiO2 nanolayer/Ag NP structures on titanium disks using atomic layer deposition (ALD). The samples were studied by scanning electron microscopy (SEM), X-ray diffraction, X-ray photoelectron spectroscopy (XPS), contact angle measurements, and SEM-EDS. Antibacterial activity was tested against Staphylococcus aureus. The in vitro cytological response of MG-63 osteosarcoma and human fetal mesenchymal stem cells (FetMSCs) was examined using SEM study of their morphology, MTT test of viability and differentiation using alkaline phosphatase and osteopontin with and without medium-induced differentiation in the osteogenic direction. The samples with TiO2 nanolayers, Ag NPs, and a TiO2/Ag combination showed high antibacterial activity, differentiation in the osteogenic direction, and non-cytotoxicity. The medium for differentiation significantly improved osteogenic differentiation, but the ALD coatings also stimulated differentiation in the absence of the medium. The TiO2/Ag samples showed the best antibacterial ability and differentiation in the osteogenic direction, indicating the success of the combining of TiO2 and Ag to produce a multifunctional biocompatible and bactericidal material.

24 November 2023 in Antibiotics
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Denis NazarovDenis Nazarov
Denis Nazarov
LKLada Kozlova
Lada Kozlova
ERElizaveta Rogacheva
Elizaveta Rogacheva
LKLiudmila Kraeva
Liudmila Kraeva
Maxim MaximovMaxim Maximov
Maxim Maximov
In recent years, antibacterial coatings have become an important approach in the global fight against bacterial pathogens. Developments in materials science, chemistry, and biochemistry have led to a plethora of materials and chemical compounds that have the potential to create antibacterial coatings. However, insufficient attention has been paid to the analysis of the techniques and technologies used to apply these coatings. Among the various inorganic coating techniques, atomic layer deposition (ALD) is worthy of note. It enables the successful synthesis of high-purity inorganic nanocoatings on surfaces of complex shape and topography, while also providing precise control over their thickness and composition. ALD has various industrial applications, but its practical application in medicine is still limited. In recent years, a considerable number of papers have been published on the proposed use of thin films and coatings produced via ALD in medicine, notably those with antibacterial properties. The aim of this paper is to carefully evaluate and analyze the relevant literature on this topic. Simple oxide coatings, including TiO2, ZnO, Fe2O3, MgO, and ZrO2, were examined, as well as coatings containing metal nanoparticles such as Ag, Cu, Pt, and Au, and mixed systems such as TiO2-ZnO, TiO2-ZrO2, ZnO-Al2O3, TiO2-Ag, and ZnO-Ag. Through comparative analysis, we have been able to draw conclusions on the effectiveness of various antibacterial coatings of different compositions, including key characteristics such as thickness, morphology, and crystal structure. The use of ALD in the development of antibacterial coatings for various applications was analyzed. Furthermore, assumptions were made about the most promising areas of development. The final section provides a comparison of different coatings, as well as the advantages, disadvantages, and prospects of using ALD for the industrial production of antibacterial coatings.