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Your search keyword '"Svorcik, Vaclav"' showing total 223 results
Start Over Author "Svorcik, Vaclav" Publication Type Academic Journals
223 results on '"Svorcik, Vaclav"'

19. Covalent functionalization of Ti3C2T MXene flakes with Gd-DTPA complex for stable and biocompatible MRI contrast agent

Author

Neubertova, Viktoria, Guselnikova, Olga, Yamauchi, Yusuke, Olshtrem, Anastasia, Rimpelova, Silvie, Čižmár, Erik, Orendáč, Martin, Duchon, Jan, Volfova, Lenka, Lancok, Jan, Herynek, Vit, Fitl, Premysl, Ulbrich, Pavel, Jelinek, Ludek, Schneider, Patrik, Kosek, Juraj, Postnikov, Pavel, Kolska, Zdenka, Svorcik, Vaclav, Chertopalov, Sergii, and Lyutakov, Oleksiy

Published
2022
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28. Enhanced photoelectrochemical nitrogen reduction to ammonia by a plasmon-active Au grating decorated with the gC3N4@MoS2 heterosystem and plasmon-active nanoparticles.

Author

Zabelin, Denis, Tulupova, Anastasiia, Zabelina, Anna, Tosovska, Andrea, Valiev, Rashid, Ramazanov, Ruslan, Mares, David, Jerabek, Vitezslav, Burtsev, Vasilii, Erzina, Mariia, Michalcová, Alena, Skvortsova, Anastasiia, Svorcik, Vaclav, and Lyutakov, Oleksiy

Abstract

The electrochemical production of ammonia from nitrogen (so-called nitrogen reduction reaction – NRR) is one of the key tasks of modern electrochemistry. The use of photo-electrochemical approaches in the NRR allows the involvement of renewable sunlight energy and partially reduces the energy demand of the NRR process and increases its efficiency. For efficient photoelectrochemical NRR realization, a rational design of the photoelectrode used is required. In this work, we propose the design, creation, and optimization of a hybrid electrode, based on utilization of coupled 2D semiconductors and plasmonic hot spots. In our approach, the gC3N4@MoS2 semiconductor (in the form of 2D flakes), with high catalytic activity towards the NRR is used as a redox-active material. For the involvement of sunlight energy, plasmon triggering is used in two modes: simple plasmonic triggering using a periodic Au grating and coupled plasmon triggering through the sandwiching of 2D gC3N4@MoS2 flakes between the Au grating and different plasmon active nanoparticles (gold and silver nanoparticles with different shapes). We also carried out a series of calculations (including finite difference time domain estimation of plasmon energy distribution and density functional calculation) aimed at the estimation of the local value of plasmon energy and the NRR process under conditions of plasmon triggering. As a result of careful design and photoelectrode optimization, we were able to achieve 882.1 μg h−1 mgcat−1 ammonia yield and 22.1% faradaic efficiency. The proposed photoelectrode design makes it possible to effectively use both the catalytic properties of the coupled semiconductors and the strengths of plasmon-assisted triggering. [ABSTRACT FROM AUTHOR]

Published
2024
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29. Plasmon‐Mediated Organic Photoelectrochemistry Applied to Amination Reactions.

Author

Buravets, Vladislav, Gorin, Oleg, Burtsev, Vasilii, Zabelina, Anna, Zabelin, Denis, Kosina, Jiri, Maixner, Jaroslav, Svorcik, Vaclav, Kolganov, Alexander A., Pidko, Evgeny A., and Lyutakov, Oleksiy

Subjects
ORGANIC electrochemistry, CHEMICAL amplification, DENSITY functional theory, ORGANIC compounds, REGIOSELECTIVITY (Chemistry), BENZENE derivatives
Abstract

Organic electrochemistry is currently experiencing an era of renaissance, which is closely related to the possibility of carrying out organic transformations under mild conditions, with high selectivity, high yields, and without the use of toxic solvents. Combination of organic electrochemistry with alternative approaches, such as photo‐chemistry was found to have great potential due to induced synergy effects. In this work, we propose for the first time utilization of plasmon triggering of enhanced and regio‐controlled organic chemical transformation performed in photoelectrochemical regime. The advantages of the proposed route is demonstrated in the model amination reaction with formation of C−N bond between pyrazole and substituted benzene derivatives. Amination was performed in photo‐electrochemical mode on the surface of plasmon active Au@Pt electrode with attention focused on the impact of plasmon triggering on the reaction efficiency and regio‐selectivity. The ability to enhance the reaction rate significantly and to tune products regio‐selectivity is demonstrated. We also performed density functional theory calculations to inquire about the reaction mechanism and potentially explain the plasmon contribution to electrochemical reaction rate and regioselectivity. [ABSTRACT FROM AUTHOR]

Published
2024
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43. Homochiral Optical Fibers Coated with Nanoscale Films of Metal–Organic Frameworks and Double-Plasmonic Ag and Au for In Situ Enantioselective Detection.

Author

Miliutina, Elena, Shilenko, Vera, Burtsev, Vasilii, Petkevich, Anna, Elashnikov, Roman, Buravets, Vladislav, Kolska, Zdenka, Kohout, Michal, Svorcik, Vaclav, and Lyutakov, Oleksiy

Abstract

Chiral recognition and detection of organic compounds represent an important task in the pharmaceutical, biological, and chemical industries since the difference between organic isomers strictly determines their biological activity and medical impact. Common enantioselective analysis performed with sophisticated equipment requires specially trained staff and a longer period of time. In this work, we propose a functional plasmonic fiber for online enantioselective detection and recognition of small organic molecules–cysteine, tyrosine, and omeprazole. Two nanothick layers of plasmon-active metals (Au and Ag) were deposited on the core(s) of a single optical fiber, giving rise to two plasmon absorption bands, which are well evident in transmitted light. The metal surface(s) was grafted with homochiral metal–organic frameworks (HMOFs), with subnanometer chiral pores, which ensured the enantioselective capture of organic enantiomers from their solution. The capture of organic moieties by grafted HMOF(s) (l- or d-MOF-6) results in their preconcentration near the plasmon-active metals, i.e., in the space of plasmonic "evanescent plasmon wave" excitation. As a result of the local enantiomer capture and corresponding changes in the shrouding refractive index, the wavelength shift of the plasmon absorption band(s) position occurs (for one plasmon absorption band in the case of one enantiomer presence or for both plasmon absorption bands in the case of an enantiomer mixture). Such a design of functional double-plasmon-active optical fiber allows the qualitative and quantitative detection of the enantiomers of small organic molecules. The proposed enantioselective detection approach is simple, fast, and based on low-cost equipment. [ABSTRACT FROM AUTHOR]

Published
2024
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