TY - JOUR AU - Casian-Plaza, F.A. AU - Janovszky, Patrick Martin AU - Palásti, Dávid Jenő AU - Kohut, Attila AU - Geretovszky, Zsolt AU - Heszlerné Kopniczky, Judit AU - Schubert, Félix AU - Živković, S. AU - Galbács, Zoltán Mihály AU - Galbács, Gábor TI - Comparison of three nanoparticle deposition techniques potentially applicable to elemental mapping by nanoparticle-enhanced laser-induced breakdown spectroscopy JF - APPLIED SURFACE SCIENCE J2 - APPL SURF SCI VL - 657 PY - 2024 PG - 9 SN - 0169-4332 DO - 10.1016/j.apsusc.2024.159844 UR - https://m2.mtmt.hu/api/publication/34723819 ID - 34723819 LA - English DB - MTMT ER - TY - JOUR AU - Jönsson, L. AU - Snellman, M. AU - Eriksson, A.C. AU - Kåredal, M. AU - Wallenberg, R. AU - Blomberg, S. AU - Kohut, Attila AU - Hartman, L. AU - Messing, M.E. TI - The effect of electrode composition on bimetallic AgAu nanoparticles produced by spark ablation JF - JOURNAL OF AEROSOL SCIENCE J2 - J AEROSOL SCI VL - 177 PY - 2024 SN - 0021-8502 DO - 10.1016/j.jaerosci.2023.106333 UR - https://m2.mtmt.hu/api/publication/34484287 ID - 34484287 LA - English DB - MTMT ER - TY - JOUR AU - Palásti, Dávid Jenő AU - Villy, Lajos Péter AU - Leits, B. AU - Kéri, Albert AU - Kohut, Attila AU - Bélteki, Ádám AU - Kajner, Gyula AU - Casian Plaza, Fernando Alexander AU - Kovács-Széles, Éva AU - Ajtai, Tibor AU - Veres, Miklós AU - Geretovszky, Zsolt AU - Galbács, Gábor TI - Detection and characterization of mono- and bimetallic nanoparticles produced by electrical discharge plasma generators using laser-induced breakdown spectroscopy JF - SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY J2 - SPECTROCHIM ACTA B VL - 209 PY - 2023 PG - 7 SN - 0584-8547 DO - 10.1016/j.sab.2023.106804 UR - https://m2.mtmt.hu/api/publication/34536295 ID - 34536295 LA - English DB - MTMT ER - TY - JOUR AU - Kohut, Attila AU - Villy, Lajos Péter AU - Kohut, Gergely AU - Galbács, Gábor AU - Geretovszky, Zsolt TI - A Calibration-Free Optical Emission Spectroscopic Method to Determine the Composition of a Spark Discharge Plasma Used for AuAg Binary Nanoparticle Synthesis JF - APPLIED SPECTROSCOPY J2 - APPL SPECTROSC VL - 77 PY - 2023 IS - 12 SP - 1401 EP - 1410 PG - 10 SN - 0003-7028 DO - 10.1177/00037028231207358 UR - https://m2.mtmt.hu/api/publication/34393015 ID - 34393015 AB - Spark discharge generators (SDGs) employ controlled gaseous environments to induce spark ablation of non-insulating electrodes, resulting in the formation of various nanostructures in the gas phase. The method offers technological advantages such as continuous particle production, scalable yield, and minimal waste. Additionally, the versatility of the process enables the generation of alloy nanoparticles from various material combinations, including immiscible ones. In order to fully exploit its potential, understanding the atomic mixing process during electrode ablation, particularly in the case of dissimilar electrodes, is crucial. Temporally and spatially resolved optical emission spectroscopy (OES) has been previously demonstrated as an effective characterization tool for spark plasmas in SDGs. However, to gain a deeper insight into the vapor mixing process, it is essential to quantitatively determine the plasma composition in both space and time. This paper introduces a calibration-free OES-based method tailored for spark plasmas utilized in binary nanoparticle generation. The method introduces the so-called multi-element combinatory Boltzmann plots, which use intensity ratios of emission atomic lines from different materials, allowing for the direct estimation of total number concentration ratios. The approach is tested using synthetic spectra and validated with experimental spark spectra obtained near an alloyed gold–silver (AuAg) electrode with a known composition. The study demonstrates the capabilities and robustness of the proposed method, with a focus on the AuAg system due to its significance in plasmonic research and frequent synthesis using spark ablation. LA - English DB - MTMT ER - TY - CHAP AU - Csarnovics, István AU - Veres, Miklós AU - Bonyár, Attila AU - Gebavi, Hrvoje AU - Kohut, Attila AU - Juhász, Laura AU - Kóródi, Zoltán AU - Feczus, Milán AU - Pál, Petra ED - IEEE, Staff TI - Peculiarities of using different nanostructures for surface-enhanced Raman scattering T2 - 2023 46th International Spring Seminar on Electronics Technology (ISSE) VL - 2023-May PB - IEEE CY - Timisoara SN - 9798350334845 PY - 2023 PG - 4 DO - 10.1109/ISSE57496.2023.10168476 UR - https://m2.mtmt.hu/api/publication/34085486 ID - 34085486 AB - Raman scattering as an effective tool for material characterization has one disadvantage which could be solved by using metallic nanostructures. As a result of this, Raman signals of the studied structures could be enhanced by different nanostructures by using surface-enhance Raman scattering (SERS). The enhancement of the SERS process depends on the material, shape, and geometrical parameters of the nanoparticles, while at the same time on the excitation wavelength and the nature of the selected analyte. Different nanostructures (nanoislands, nanoparticles, nano trees) were created and analyzed, and their parameters were optimized to obtain a higher enhancement factor and to find out the detection limit of the selected analyte. Also, the different creation methods were compared from the point of view of the sensing application. LA - English DB - MTMT ER - TY - JOUR AU - Pál, Petra AU - Horváth, Viktória AU - Juhász, Laura AU - Kóródi, Zoltán AU - Kohut, Attila AU - Csarnovics, István TI - Fabrication of Nanoparticle Agglomerate Films by Spark Ablation and Their Application in Surface-Enhanced Raman Spectroscopy JF - CHEMOSENSORS J2 - CHEMOSENSORS VL - 11 PY - 2023 IS - 3 PG - 16 SN - 2227-9040 DO - 10.3390/chemosensors11030180 UR - https://m2.mtmt.hu/api/publication/33688528 ID - 33688528 AB - This paper presents a systematic study of the investigation of nanoparticle (NP) agglomerate films fabricated via depositing spark-generated Au, Ag, and Au/Ag NPs onto quartz microscope coverslips in a low-pressure inertial impactor. The primary focus of the study is to characterize these nanostructures and to examine their potential application in surface-enhanced Raman spectroscopy (SERS). The characterization of the produced nanostructures was carried out by performing optical absorbance measurements, morphology, and composition analysis, as well as testing the SERS performance of the NP films at three different excitation laser wavelengths in the visible range. The study aims to investigate the relationship between the optical properties, the morphology, and the enhancement of the produced samples at different excitations, and the results are presented and discussed. The study highlights the potential of using spark ablation and inertial impaction-based deposition as a method for producing nanoparticle films for SERS. LA - English DB - MTMT ER - TY - JOUR AU - Kohut, Attila TI - Hydrogen-assisted spark generation of silver nanoparticles: The effect of hydrogen content on the signal intensity in surface-enhanced Raman spectroscopy JF - JOURNAL OF AEROSOL SCIENCE J2 - J AEROSOL SCI VL - 167 PY - 2023 PG - 6 SN - 0021-8502 DO - 10.1016/j.jaerosci.2022.106090 UR - https://m2.mtmt.hu/api/publication/33134647 ID - 33134647 LA - English DB - MTMT ER - TY - JOUR AU - Villy, Lajos Péter AU - Kohut, Attila AU - Kéri, Albert AU - Bélteki, Ádám AU - Radnóczi, György AU - Fogarassy, Zsolt AU - Radnóczi, György Zoltán AU - Galbács, Gábor AU - Geretovszky, Zsolt TI - Continuous spark plasma synthesis of Au/Co binary nanoparticles with tunable properties JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 12 PY - 2022 IS - 1 PG - 9 SN - 2045-2322 DO - 10.1038/s41598-022-22928-0 UR - https://m2.mtmt.hu/api/publication/33208918 ID - 33208918 AB - We present here a scalable and environmentally friendly gas phase technique employing atmospheric pressure electrical spark discharge plasmas for the production of Au/Co binaries, an effective catalyst system for the decomposition of hydrogen-rich compounds, such as ammonium borane. We demonstrate that Au/Co alloy nanoparticles can be produced via the spark plasma-based technique. The possibility of varying the morphology and phase structure via real time heat treatment of the generated aerosol to form Au/Co/CoO particles with continuous control over a wide particle compositional range (from 24 to 64 at.% [Co]/([Co] + [Au]) content) is also demonstrated. Since our spark-based approach is proven to be capable of providing reasonable particle yields, these results may contribute to the transition of lab-scale, nanocatalyst-based hydrogen storage systems to real world applications. LA - English DB - MTMT ER - TY - JOUR AU - Ajtai, Tibor AU - Kohut, Attila AU - Raffai, Péter AU - Szabó, Gábor AU - Bozóki, Zoltán TI - Controlled Laboratory Generation of Atmospheric Black Carbon Using Laser Excitation-Based Soot Generator: From Basic Principles to Application Perspectives: A Review JF - ATMOSPHERE J2 - ATMOSPHERE-BASEL VL - 13 PY - 2022 IS - 9 PG - 18 SN - 2073-4433 DO - 10.3390/atmos13091366 UR - https://m2.mtmt.hu/api/publication/33134648 ID - 33134648 AB - The mimicking of atmospheric soot with versatile chemophysical properties is a critical issue in many applications, starting from instrument calibration, through producing aerosol standards for academic research, and ending with the reduction of uncertainties associated to carbonaceous particulate matter in the atmosphere, just to name a few. The present study deals with laser ablation as a novel and interesting technique for the generation of soot with high elementary carbon (EC) content with microphysical features similar to diesel or atmospheric soot and for modelling biomass emission under well-controlled laboratory conditions. The operation of the laser-excitation-based soot generator and the characteristics of the produced particles are compared to the most widely used techniques like flame, spark discharge generators, and real combustion soot originating from diesel- and aircraft engines or from field measurement. The comparison shows that significant differences in the physicochemical features exist between the real combustion soot and the soot originating from different excitation mechanisms. Moreover, the soot produced by different techniques shown also significant differences. However, due to some inherent and favorable attributes of the laser ablation technique—such as the possibility of the independent variation of physical characteristics of the generated soot particles—the potential for modelling biomass burning or to produce soot particles even in the accumulation mode makes it a useful tool in many cases. LA - English DB - MTMT ER - TY - JOUR AU - Palásti, Dávid Jenő AU - Villy, Lajos Péter AU - Kohut, Attila AU - Ajtai, Tibor AU - Geretovszky, Zsolt AU - Galbács, Gábor TI - Laser-induced breakdown spectroscopy signal enhancement effect for argon caused by the presence of gold nanoparticles JF - SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY J2 - SPECTROCHIM ACTA B VL - 193 PY - 2022 PG - 9 SN - 0584-8547 DO - 10.1016/j.sab.2022.106435 UR - https://m2.mtmt.hu/api/publication/32836484 ID - 32836484 LA - English DB - MTMT ER -