TY - JOUR AU - Pósfai, Mihály TI - Bevezetés a tematikus blokkhoz JF - FIZIKAI SZEMLE J2 - FIZIKAI SZEMLE VL - 74 PY - 2024 IS - 2 SP - 38 EP - 38 PG - 1 SN - 0015-3257 UR - https://m2.mtmt.hu/api/publication/34738036 ID - 34738036 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Molnár, Zsombor AU - Pekker, Péter AU - Rečnik, Aleksander AU - Pósfai, Mihály TI - Formation and properties of spindle-shaped aragonite mesocrystals from Mg-bearing solutions JF - NANOSCALE J2 - NANOSCALE VL - 16 PY - 2024 IS - 4 SP - 2012 EP - 2021 PG - 10 SN - 2040-3364 DO - 10.1039/D3NR04672A UR - https://m2.mtmt.hu/api/publication/34499208 ID - 34499208 AB - Spindle-shaped aragonite mesocrystals form by the attachment of Mg-bearing amorphous calcium carbonate particles that convert to aragonite nanocrystals through dissolution-reprecipitation. LA - English DB - MTMT ER - TY - CHAP AU - UDDIN, IMRAN AU - Shoaib, Mukhtar AU - Molnár, Zsombor AU - Pósfai, Mihály TI - Low-temperature synthesis of graphene/Ag nanocomposite as a photo-catalyst for the degradation of organic pollutants in wastewater T2 - Műszaki Kémiai Napok 2023 Konferencia PB - Pannon Egyetem CY - Veszprém SN - 9789633962565 PY - 2023 SP - 44 UR - https://m2.mtmt.hu/api/publication/34731769 ID - 34731769 AB - We prepared a composite of graphene (Gr) and silver (Ag) nanoparticles by using chemically exfoliated graphene as the base matrix, and biosynthesized Ag nanoparticles. TEM micrographs show that Gr has a 2D delaminated layered structure with a sheet-like morphology, with a moderate concentration of isometric Ag NPs well dispersed over the basal planes of the Gr nanosheet. UV-visible absorption spectroscopy reveals a hump around 265 nm, which corresponds to π-π* electron resonance transitions owing to aromatic sp2 hybridized C-C bonds in graphene sheets, and a peak at 401 nm, which is attributed to Ag NPs. The photocatalytic potential of Gr/Ag nanocomposites was studied using the degradation of organic dyes (methylene blue, 4-nitrophenol, and cumarin) as models of water pollutants. The experiments show that the methylene blue degradation efficacy of the Gr/Ag nanocomposite catalyst after 2 hours is about 97% and 90% using UV and visible light irradiation, respectively. Furthermore, the Gr/Ag nanocomposite showed significant degradation activity toward 4-nitrophenol, and cumarin dye. This study suggests the nanocomposite synthesized at low temperatures can be used as an efficient adaptable photocatalyst for the photodegradation of organic dyes in industrial wastewater. LA - English DB - MTMT ER - TY - CONF AU - Pálfi, Ivett AU - Pósfai, Mihály AU - Demény, Attila AU - Czuppon, György AU - Pekker, Péter AU - May, Zoltán AU - Visnovitz, Ferenc AU - Kristály, Ferenc AU - Veres, D AU - Arnoud, F AU - Szalai, Zoltán AU - Korponai, J AU - Molnár, M AU - Szabó, Z AU - Magyari, Enikő Katalin ED - Kovács, B ED - Virthné Kemes, K TI - Environmental and climatic changes over the past 10 000 years inferred from geochemistry of Lake Balaton T2 - Víz- és szennyvízkezelés az iparban (VSZI '23) : IX. Soós Ernő Nemzetközi Tudományos Konferencia = Water and wastewater treatment in the industry 2023 : IX. Soós Ernő International Scientific Conference PB - Soós Ernő Kutató-fejlesztő Központ C1 - Nagykanizsa PY - 2023 SP - 38 UR - https://m2.mtmt.hu/api/publication/34525833 ID - 34525833 N1 - Poszter LA - English DB - MTMT ER - TY - JOUR AU - Blichert-Toft, J. AU - Canfield, D. AU - Gleeson, S. AU - Pancost, R. AU - Pósfai, Mihály TI - Carbon Capture and Storage: From Global Cycles to Global Solutions JF - GEOCHEMICAL PERSPECTIVES J2 - GEOCHEM PERSPECT VL - 12 PY - 2023 IS - 2 SP - 179 EP - 349 PG - 171 SN - 2223-7755 DO - 10.7185/geochempersp.12.2 UR - https://m2.mtmt.hu/api/publication/34430397 ID - 34430397 N1 - Export Date: 12 December 2023; Cited By: 0 AB - Anthropogenic carbon emissions have overwhelmed the natural carbon cycle, leading to a dramatic increase in atmospheric CO2 concentration. The rate of this increase may be unprecedented in Earth's history and is leading to a substantial increase in global temperatures, ocean acidification, sea level rise and potentially human health challenges. In this Geochemical Perspectives we review the natural carbon cycle and its link to global climate. Notably, as directly observed by field observations summarised in this volume, there is a natural negative feedback loop between increasing global temperature, continental weathering rates, and CO2 that has tended to limit Earth climate changes over geological time scales. Due to the rapid increase in atmospheric carbon concentrations, global average temperatures have increased by more than 1.2 oC since the start of the industrial revolution. One way to slow or even arrest this increasing global average temperature is through Carbon Capture and Storage (CCS). Carbon dioxide can be captured either from large industrial point sources or directly from the atmosphere. Taking account of the natural carbon cycle, the most secure approach to storing captured CO2 is by reacting it with mafic or ultramafic rocks to form stable carbonate minerals, a process referred to as "mineral carbonation". Although mineral carbonation can occur and be accelerated at the Earth's surface, due to the required scale and required time frames it is most effective in the subsurface. This subsurface mineralisation approach was developed into an industrial scale process through an academic-industrial collaboration called CarbFix. The history of CarbFix, from its beginnings as a concept through its installation as an industrial process is presented in detail. This Geochemical Perspectives concludes with an assessment of the future of subsurface mineralisation as a means to help address the global warming challenge, as well as a detailed list of potential research directions that need to be addressed to further upscale and optimise this carbon storage approach. © 2023 Associacao Portuguesa de Estudos sobre as Mulheres. All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - Dziuba, Marina V. AU - Müller, Frank-Dietrich AU - Pósfai, Mihály AU - Schüler, Dirk TI - Exploring the host range for genetic transfer of magnetic organelle biosynthesis JF - NATURE NANOTECHNOLOGY J2 - NAT NANOTECHNOL VL - 2023 PY - 2023 SN - 1748-3387 DO - 10.1038/s41565-023-01500-5 UR - https://m2.mtmt.hu/api/publication/34162019 ID - 34162019 LA - English DB - MTMT ER - TY - JOUR AU - Lange, Thomas Pieter AU - Pálos, Zsófia AU - Pósfai, Mihály AU - Berkesi, Márta AU - Pekker, Péter AU - Szabó, Ábel AU - Szabó, Csaba AU - Kovács, István János TI - Nanoscale hydrous silicate melt inclusions at the clinopyroxene-amphibole interface in a mantle xenolith from the Perșani Mountains Volcanic Field JF - LITHOS J2 - LITHOS VL - 454-455 PY - 2023 PG - 13 SN - 0024-4937 DO - 10.1016/j.lithos.2023.107210 UR - https://m2.mtmt.hu/api/publication/34014104 ID - 34014104 N1 - Lithosphere Fluid Research Lab, Institute of Geography and Earth Sciences, Eötvös Loránd University, Budapest, Hungary Doctoral School of Environmental Sciences, Eötvös Loránd University, Budapest, Hungary MTA FI Lendület Pannon LitH2Oscope Research Group, Hungary Institute of Earth Physics and Space Science, Csatkai Endre utca 6-8, Sopron, 9400, Hungary ELKH, CSFK, Institute for Geological and Geochemical Research, Budaörsi út 45, Budapest, 1112, Hungary University of Geneva, Department of Earth Sciences, Mineral Resources and Geofluids Group Université de Genève 13, Rue des Maraîchers, Genève, 1205, Switzerland Research Institute of Biomolecular and Chemical Engineering, Nanolab, University of Pannonia, Veszprém, Hungary ELKH-PE Environmental Mineralogy Research Group, Egyetem u. 10, Veszprém, 8200, Hungary MTA FI Lendület FluidsByDepth Research Group, Hungary Export Date: 19 June 2023 Correspondence Address: Lange, T.P.; Lithosphere Fluid Research Lab (LRG), Pázmány Péter sétány 1/c, Budapest H-1117, Hungary; email: lange.thomas@epss.hu LA - English DB - MTMT ER - TY - CONF AU - Molnár, Zsombor AU - Pekker, Péter AU - Pósfai, Mihály TI - The roles of precursor (Mg)-ACC in the formation of aragonite T2 - Goldschmidt 2023 Conference: abstracts PB - European Association of Geochemistry PY - 2023 UR - https://m2.mtmt.hu/api/publication/33879103 ID - 33879103 AB - Amorphous calcium carbonate (ACC) is often referred to as a phase that can transform into either of the three anhydrous crystalline CaCO3 forms (calcite, aragonite and vaterite). Here, we examined the conditions that make ACC transform into aragonite. Even though aragonite is the stable anhydrous crystalline CaCO3 polymorph at high pressure (4–40 GPa), it is also widespread on Earth’s surface. Nevertheless, the mechanism of its formation and the roles of solid precursors (such as ACC) in the process have not been studied as extensively as in the case of calcite. We studied aragonite formation by synthesizing it under laboratory conditions, focusing on the two, environmentally most relevant factors that are known to enhance its formation: (i) the presence of dissolved Mg2+ ions and (ii) the temperature of the mother solution (up to 80 °C). We used different experimental approaches in the two cases, and studied the precipitated materials with various scanning transmission electron microscopy (STEM) techniques. In Mg-rich solutions the first solid product was Mg-bearing ACC that transformed into aragonite aggregates with a typical, spindle-like appearance. Each spindle was an aggregate of crystallographically oriented nanocrystals, and two or more spindles could form star-like assemblies, with their members in twin orientation. Whereas the remarkable hierarchical structure suggested a growth mechanism by nanoparticle attachment, chemical differences observed between Mg-bearing ACC and aragonite indicated that the process must have involved dissolution and re-precipitation (DRP) as well. At elevated temperature ACC particles formed in the highly supersaturated (Mg-free) solutions, and their electron diffraction analysis suggested a trend of structural change with increasing temperature. The increasing temperature accelerated the transformation of ACC into crystalline forms (both calcite and aragonite), with aragonite formation favored at 80 °C. Morphological features suggested that the ACC could transform into either calcite or aragonite in solid state (preserving the globular shape of ACC), while simultaneously DRP produced aragonite crystals with aggregate or needle-like appearance. Thus, aragonite formation from ACC involved particle aggregation coupled with DRP in Mg-rich solutions, and solid-state transformation coupled with DRP at elevated temperatures. [1] [1] Support from NKFIH under grants RRF-2.3.1-21-2022-00014 and SNN-139585 is acknowledged. LA - English DB - MTMT ER - TY - JOUR AU - Meister, P AU - Frisia, S AU - Dódony, István AU - Pekker, Péter AU - Molnár, Zsombor AU - Neuhuber, S AU - Gier, S AU - Kovács, Ivett AU - Demény, Attila AU - Pósfai, Mihály TI - Nanoscale Pathway of Modern Dolomite Formation in a Shallow, Alkaline Lake JF - CRYSTAL GROWTH & DESIGN J2 - CRYST GROWTH DES VL - 23 PY - 2023 IS - 5 SP - 3202 EP - 3212 PG - 11 SN - 1528-7483 DO - 10.1021/acs.cgd.2c01393 UR - https://m2.mtmt.hu/api/publication/33741775 ID - 33741775 LA - English DB - MTMT ER - TY - JOUR AU - Molnár, Zsombor AU - Dódony, István AU - Pósfai, Mihály TI - Transformation of amorphous calcium carbonate in the presence of magnesium, phosphate, and mineral surfaces JF - GEOCHIMICA ET COSMOCHIMICA ACTA J2 - GEOCHIM COSMOCHIM AC VL - 345 PY - 2023 SP - 90 EP - 101 PG - 12 SN - 0016-7037 DO - 10.1016/j.gca.2023.01.028 UR - https://m2.mtmt.hu/api/publication/33628972 ID - 33628972 N1 - University of Pannonia, Research Institute of Biomolecular and Chemical Engineering, Nanolab, Egyetem st. 10, Veszprém, 8200, Hungary ELKH-PE Environmental Mineralogy Research Group, Egyetem st. 10, Veszprém, 8200, Hungary Cited By :7 Export Date: 14 March 2024 Correspondence Address: Molnár, Z.; University of Pannonia, Nanolab, Egyetem st. 10, Hungary; email: molnar.zsombor@mk.uni-pannon.hu LA - English DB - MTMT ER -