TY - JOUR AU - Koppány, Ferenc AU - Csomó, Krisztián Benedek AU - Varmuzsa, Edvárd Márton AU - Bognár, Eszter AU - Pelyhe, Liza AU - Nagy, Péter AU - Kientzl, Imre AU - Szabó, Dániel AU - Weszl, Miklós AU - Dobos, Gábor AU - Lenk, Sándor AU - Erdei, Gábor AU - Kiss, Gábor AU - Nagy, Lilien AU - Sréter, Attila AU - Belik, Andrea AU - Tóth, Zsuzsanna AU - Vág, János AU - Joób-Fancsaly, Árpád AU - Németh, Zsolt TI - Enhancement of Hydrophilicity of Nano-Pitted TiO2 Surface Using Phosphoric Acid Etching JF - NANOMATERIALS J2 - NANOMATERIALS-BASEL VL - 13 PY - 2023 IS - 3 PG - 9 SN - 2079-4991 DO - 10.3390/nano13030511 UR - https://m2.mtmt.hu/api/publication/33607227 ID - 33607227 N1 - Funding Agency and Grant Number: REA [FP7-SME-2013-606624] Funding text: This research was funded by REA in the 7th Framework Program within the funding scheme of SME Instrument under the scope of the NANOTI Project (FP7-SME-2013-606624). AB - Our research group developed a novel nano-pitted (NP) TiO2 surface on grade 2 titanium that showed good mechanical, osteogenic, and antibacterial properties; however, it showed weak hydrophilicity. Our objective was to develop a surface treatment method to enhance the hydrophilicity of the NP TiO2 surface without the destruction of the nano-topography. The effects of dilute and concentrated orthophosphoric (H3PO4) and nitric acids were investigated on wettability using contact angle measurement. Optical profilometry and atomic force microscopy were used for surface roughness measurement. The chemical composition of the TiO2 surface and the oxidation state of Ti was investigated using X-ray photoelectron spectroscopy. The ccH3PO4 treatment significantly increased the wettability of the NP TiO2 surfaces (30°) compared to the untreated control (88°). The quantity of the absorbed phosphorus significantly increased following ccH3PO4 treatment compared to the control and caused the oxidation state of titanium to decrease (Ti4+ → Ti3+). Owing to its simplicity and robustness the presented surface treatment method may be utilized in the industrial-scale manufacturing of titanium implants. LA - English DB - MTMT ER - TY - JOUR AU - Domán, Andrea AU - Battalgazy, B. AU - Dobos, Gábor AU - Kiss, Gábor AU - Tauanov, Z. AU - Nagyné László, Krisztina AU - Zorpas, A.A. AU - Inglezakis, V.J. TI - Iodide Removal by Resorcinol-Formaldehyde Carbon Aerogels JF - MATERIALS J2 - MATERIALS VL - 15 PY - 2022 IS - 19 PG - 15 SN - 1996-1944 DO - 10.3390/ma15196885 UR - https://m2.mtmt.hu/api/publication/33189813 ID - 33189813 N1 - Surface Chemistry Group, Department of Physical Chemistry and Materials Science, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Műegyetem rkp. 3, Budapest, 1111, Hungary Environmental Science & Technology Group (ESTg), Department of Chemical & Materials Engineering, School of Engineering, Nazarbayev University, Qabanbay Batyr Ave 53, Nur-Sultan, 010000, Kazakhstan Surface Physics Laboratory, Department of Atomic Physics, Budapest University of Technology and Economics, Műegyetem rkp. 3, Budapest, 1111, Hungary Faculty of Chemistry and Chemical Technology, al-Farabi Kazakh National University, 71 al-Farabi Ave, Almaty, 050040, Kazakhstan Laboratory of Chemical Engineering and Engineering Sustainability, Faculty of Pure and Applied Science, Open University of Cyprus, Giannou Kranidioti 33, Latsia, Nicosia, 2220, Cyprus Chemical and Process Engineering Department, University of Strathclyde, 75 Montrose Street, Glasgow, G1 1XJ, United Kingdom Export Date: 14 February 2023 Correspondence Address: Zorpas, A.A.; Laboratory of Chemical Engineering and Engineering Sustainability, Giannou Kranidioti 33, Latsia, Cyprus; email: antoniszorpas@yahoo.com Correspondence Address: Inglezakis, V.J.; Chemical and Process Engineering Department, 75 Montrose Street, United Kingdom; email: vasileios.inglezakis@strath.ac.uk Funding details: TKP2021-EGA-02 Funding details: Ministry of Education and Science of the Republic of Kazakhstan, AP08857007 Funding text 1: This research was funded by the H2020-MSCA-RISE-2016-734641 NanoMed project, by the National Research, Development, and Innovation Fund of Hungary under Grant TKP2021-EGA-02 and by the Science Fund of the Ministry of Education and Science of Kazakhstan (Grant No. AP08857007, 2020–2022). We express our gratitude to G. Bosznai for the technical assistance. AB - The adsorption technique is widely used in water purification, and its efficiency can be significantly improved by target-specific adsorbent design. Research on iodine and its ion removal from water has attracted a great deal of interest due to increased concentrations in the environment and acute toxic effects, e.g., in human thyroid cells. In this work, the iodide removal performance of two high-surface-area resorcinol–formaldehyde-based carbon aerogels was studied under acidic conditions. The BET surface area was 790 m2/g (RF_ac) and 375 m2/g (RMF-GO), with a corresponding micropore ratio of 36 and 26%, respectively. Both aerogels showed outstanding adsorption capacity, exceeding the reported performance of other carbons and Ag-doped materials. Owing to its basic nature, the RMF-GO carbon aerogel showed higher I− capacity, up to 97 mg/g, than the acidic RF_ac, which reached a capacity of 82 mg/g. The surface chemistry of the aerogels also played a distinct role in the removal. In terms of kinetics, RF_ac removed 60% of the iodide ions and RMF-GO 30% within 8 h. The removal kinetics was of the first order, with a half-life of 1.94 and 1.70 h, respectively. LA - English DB - MTMT ER - TY - JOUR AU - Samaniego Andrade, Samantha Kathiuska AU - Bakos, István AU - Dobos, Gábor AU - Farkas, Attila AU - Kiss, Gábor AU - Klébert, Szilvia AU - Madarász, János AU - Nagyné László, Krisztina TI - Biomass Related Highly Porous Metal Free Carbon for Gas Storage and Electrocatalytic Applications JF - MATERIALS J2 - MATERIALS VL - 14 PY - 2021 IS - 13 PG - 16 SN - 1996-1944 DO - 10.3390/ma14133488 UR - https://m2.mtmt.hu/api/publication/32080023 ID - 32080023 N1 - Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, Budapest, 1521, Hungary Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Eötvös Loránd Research Network, Magyar tudósok körútja 2, Budapest, 1117, Hungary Department of Atomic Physics, Budapest University of Technology and Economics, Budapest, 1521, Hungary Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Budapest, 1521, Hungary Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Budapest, 1521, Hungary Export Date: 29 September 2021 Correspondence Address: László, K.; Department of Physical Chemistry and Materials Science, Hungary; email: laszlo.krisztina@vbk.bme.hu Funding details: 734641, H2020-MSCA-RISE-2016 Funding details: European Commission, EC Funding details: European Regional Development Fund, ERDF Funding details: National Research, Development and Innovation Office Funding text 1: This research was funded by the VEKOP-2.3.2-16-2017-00013 and 2020-3.1.1-ZFR-KVG-2020-00006 projects. The VEKOP project is supported by the EU and by Hungary, co-financed by the European Regional Development Fund, while the 2020-3.1.2-ZFR-KVG program is supported by the National Research, Development and Innovation Office (NRDI). The work is also part of the EU project NANOMED (H2020-MSCA-RISE-2016, #734641). The research was supported by the BME-Biotechnology (BME IE-BIO) TKP2020 IE grant. S.S.A. would like to thank the Stipendium Hungaricum scholarship program. LA - English DB - MTMT ER - TY - JOUR AU - Dobos, Gábor AU - Hárs, György TI - Continuous time of flight measurements in a Lissajous configuration JF - REVIEW OF SCIENTIFIC INSTRUMENTS J2 - REV SCI INSTRUM VL - 88 PY - 2017 IS - 1 PG - 6 SN - 0034-6748 DO - 10.1063/1.4971305 UR - https://m2.mtmt.hu/api/publication/3216919 ID - 3216919 AB - Short pulses used by traditional time-of-flight mass spectrometers limit their duty cycle, pose space-charge issues, and require high speed detectors and electronics. The motivation behind the invention of continuous time of flight mass spectrometers was to mitigate these problems, by increasing the number of ions reaching the detector and eliminating the need for fast data acquisition systems. The most crucial components of these spectrometers are their modulators: they determine both the maximal modulation frequency and the modulation depth. Through these parameters they limit the achievable mass resolution and signal-to-noise ratio. In this paper, a new kind of setup is presented which modulates the beam by deflecting it in two perpendicular directions and collects ions on a position sensitive detector. Such an Lissajous time of flight spectrometer achieves modulation without the use of slits or apertures, making it possible for all ions to reach the detector, thereby increasing the transmission and signal-to-noise ratio. In this paper, we provide the mathematical description of the system, discuss its properties, and present a practical demonstration of the principle. Published by AIP Publishing. LA - English DB - MTMT ER - TY - JOUR AU - Velasco, LF AU - Guillet-Nicolas, R AU - Dobos, Gábor AU - Thommes, M AU - Lodewyckx, P TI - Towards a better understanding of water adsorption hysteresis in activated carbons by scanning isotherms JF - CARBON J2 - CARBON VL - 96 PY - 2016 SP - 753 EP - 758 PG - 6 SN - 0008-6223 DO - 10.1016/j.carbon.2015.10.017 UR - https://m2.mtmt.hu/api/publication/3123346 ID - 3123346 AB - The occurrence of water sorption hysteresis associated with the filling of micro and narrow mesopores (particularly for pores of widths smaller than ca. 3 nm, where nitrogen and argon isotherms at their boiling temperatures, i.e. 77 K and 87 K, respectively, are known to be reversible) provides additional opportunities for textural characterization. In this work systematic water scanning desorption isotherms within the hysteresis loop were carried out on well-characterized activated carbons with varied textural features and surface chemistry. Accurate micro-mesopore analysis was obtained by means of nitrogen, argon and carbon dioxide adsorption experiments coupled with advanced density functional theory methods (i.e., NLDFT, QSDFT). The obtained results indicated that water adsorption/desorption phenomena for pores of different sizes take place independently from each other. This investigation constitutes a starting point for the interpretation of water adsorption hysteresis by means of scanning desorption measurements. (C) 2015 Elsevier Ltd. All rights reserved. LA - English DB - MTMT ER - TY - CHAP AU - Katona, Bálint AU - Dobos, Gábor AU - Kiss, Gábor ED - Berecz, Tibor ED - Májlinger, Kornél ED - Orbulov, Imre Norbert ED - Szabó, Péter János TI - Examination of the surface phosphorus content of anodized medical grade titanium samples T2 - Materials Science, Testing and Informatics VII PB - Trans Tech Publications CY - Zürich SN - 9783038353898 T3 - Materials science forum ; 812. PY - 2015 SP - 339 EP - 344 PG - 6 DO - 10.4028/www.scientific.net/MSF.812.339 UR - https://m2.mtmt.hu/api/publication/2834577 ID - 2834577 N1 - Budapest University of Technology and Economics, Department of Materials Science and Engineering, Bertalan L. St. 7, Budapest, H-1111, Hungary Budapest University of Technology and Economics, Department of Atomic Physics, Budafoki St. 8, Budapest, H-1111, Hungary Cited By :3 Export Date: 30 June 2022 CODEN: MSFOE LA - English DB - MTMT ER - TY - JOUR AU - K, Voitko AU - Tóth, Ajna AU - E, Demianenko AU - Dobos, Gábor AU - Berke, Barbara AU - O, Bakalinska AU - A, Grebenyuk AU - Csákiné Tombácz, Etelka AU - V, Kuts AU - Y, Tarasenko AU - M, Kartel AU - Nagyné László, Krisztina TI - Catalytic performance of carbon nanotubes in H2O2 decomposition: experimental and quantum chemical study JF - JOURNAL OF COLLOID AND INTERFACE SCIENCE J2 - J COLLOID INTERF SCI VL - 437 PY - 2015 SP - 283 EP - 290 PG - 8 SN - 0021-9797 DO - 10.1016/j.jcis.2014.09.045 UR - https://m2.mtmt.hu/api/publication/2760561 ID - 2760561 LA - English DB - MTMT ER - TY - JOUR AU - Ábrahám, Dániel János AU - Nagy, Balázs AU - Dobos, Gábor AU - Madarász, János AU - Onyestyák, György AU - Trenikhin, MV AU - Nagyné László, Krisztina TI - Hydroconversion of acetic acid over carbon aerogel supported molybdenum catalyst JF - MICROPOROUS AND MESOPOROUS MATERIALS J2 - MICROPOR MESOPOR MAT VL - 190 PY - 2014 SP - 46 EP - 53 PG - 8 SN - 1387-1811 DO - 10.1016/j.micromeso.2014.01.021 UR - https://m2.mtmt.hu/api/publication/2551650 ID - 2551650 N1 - Megjegyzés-24008739 EI: 1873-3093 : Materials Science, Multidisciplinary Megjegyzés-24455070 N1 Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, H-1521 Budapest, Hungary Department of Atomic Physics, Budapest University of Technology and Economics, H-1521 Budapest, Hungary Institute of General and Analytical Chemistry, Budapest University of Technology and Economics, H-1521 Budapest, Hungary Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary Institute of Hydrocarbon Processing, Omsk Scientific Center, Russian Academy of Sciences, Omsk 634055, Russian Federation Cited By :11 Export Date: 7 January 2020 CODEN: MIMMF Correspondence Address: László, K.; Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, H-1521 Budapest, Hungary; email: klaszlo@mail.bme.hu Funding details: TÁMOP-4.2.2., 269267 Funding text 1: The support of the Marie Curie International Research Staff Exchange Scheme (Grant No. 269267 ) and TÁMOP-4.2.2.A-11/1/KONV-2012-0043 (ENVIKUT) is gratefully acknowledged. The authors thank Sz. Harnos and Gy. Bosznai for their contributions to the experimental work, and E. Geissler for fruitful discussions. Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, H-1521 Budapest, Hungary Department of Atomic Physics, Budapest University of Technology and Economics, H-1521 Budapest, Hungary Institute of General and Analytical Chemistry, Budapest University of Technology and Economics, H-1521 Budapest, Hungary Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary Institute of Hydrocarbon Processing, Omsk Scientific Center, Russian Academy of Sciences, Omsk 634055, Russian Federation Cited By :11 Export Date: 10 March 2021 CODEN: MIMMF Correspondence Address: László, K.; Department of Physical Chemistry and Materials Science, , H-1521 Budapest, Hungary; email: klaszlo@mail.bme.hu Funding details: 269267 Funding text 1: The support of the Marie Curie International Research Staff Exchange Scheme (Grant No. 269267 ) and TÁMOP-4.2.2.A-11/1/KONV-2012-0043 (ENVIKUT) is gratefully acknowledged. The authors thank Sz. Harnos and Gy. Bosznai for their contributions to the experimental work, and E. Geissler for fruitful discussions. AB - High surface area carbon aerogels with increasing molybdenum content were obtained by carbonization of resorcinol-formaldehyde polymer aerogels after incipient wetness impregnation (IWI). The Mo(VI) form of the impregnant was converted into different molybdenum species during the heat treatment, resulting in samples with substantially different surface and bulk compositions. The samples were tested in the hydroconversion reaction of acetic acid, a model biomass. The reaction pathways and the product distribution were governed by the accessibility of the carbon surface as well as by the amount and form of Mo. The highest selectivity for ethanol was 16%, when 85% of the acetic acid was converted. Post-catalyst analysis of the aerogels revealed that their morphology and chemistry changed substantially during the redox processes. The products of each of the three potential pathways (hydrogenolysis, ketonization and consecutive reduction) oxidized the surface even in the reductive hydrogen flow. © 2014 Elsevier Inc. All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - Nagy, Balázs AU - Ábrahám, Dániel János AU - Dobos, Gábor AU - Madarász, János AU - Onyestyák, György AU - Sáfrán, György AU - Geissler, E AU - Nagyné László, Krisztina TI - Molybdenum doped carbon aerogels with catalytic potential JF - CARBON J2 - CARBON VL - 66 PY - 2014 SP - 210 EP - 218 PG - 9 SN - 0008-6223 DO - 10.1016/j.carbon.2013.08.060 UR - https://m2.mtmt.hu/api/publication/2446453 ID - 2446453 AB - Mo-doped carbon aerogels were obtained in the polycondensation reaction of aqueous resorcinol and formaldehyde by adding Mo-salt at two different stages of the synthesis: (i) to the initial sol; (ii) by incipient wetting impregnation of the supercritically dried polymer gel. Molybdenum added during the polymerization yielded a more compact gel structure with practically no mesoporosity. With post-impregnation, by contrast, mesopores of diameter 3-15 nm were generated. Carbonization appreciably enhanced the microporous character of both samples, but in the mesopore range their pore size distribution was conserved. The Mo-content of the samples was also different: Mo was lost during the solvent exchange before the supercritical drying (i.e., the Mo failed to bind chemically to the polymer matrix). The residual Mo congregated into 25-60 nm bulk clusters of α-Mo2C. In the other carbon aerogel, finely dispersed α-Mo2C and η-Mo3C2 crystals formed, of size 8-20 nm. On the surface of both carbons the Mo formed oxides. In the model test reaction (acetic acid hydroconversion) the catalytic activity of both carbon aerogels was enhanced by molybdenum. The more open pore structure, higher concentration and finer Mo distribution, as well as its chemical form, may all be responsible for the greater conversion and higher value products obtained with the post-impregnated sample. © 2013 Elsevier Ltd. All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - Sebők, Béla AU - Kiss, Gábor AU - Dobos, Gábor AU - Réti, Ferenc AU - Majoros, Tamás AU - Homokiné Krafcsik, Olga TI - Novel instrument and method for the investigation of small permeation fluxes of gases through different membranes JF - MEASUREMENT J2 - MEASUREMENT VL - 46 PY - 2013 IS - 9 SP - 3516 EP - 3524 PG - 9 SN - 0263-2241 DO - 10.1016/j.measurement.2013.06.048 UR - https://m2.mtmt.hu/api/publication/2693739 ID - 2693739 LA - English DB - MTMT ER -