TY - JOUR AU - Li, Yahui AU - Feng, Quanchen AU - Nagyné László, Krisztina AU - Wang, Ying TI - High-throughput screening of high C/N-ratio homonuclear dual-atom catalysts for electrochemical reduction of nitrate to ammonia JF - CHINESE CHEMICAL LETTERS J2 - CHINESE CHEM LETT VL - 37 PY - 2026 IS - 3 PG - 7 SN - 1001-8417 DO - 10.1016/j.cclet.2025.111536 UR - https://m2.mtmt.hu/api/publication/36517695 ID - 36517695 N1 - This work was supported by National Natural Science Foundation of China (NSFC, No. 22276138), Science & Technology Commission of Shanghai Municipality (No. 22230712800), and the Fundamental Research Funds for the Central Universities and the Foundation of State Key Laboratory of Pollution Control and Resource Reuse (Tongji University) (No. 2022-4-ZD-07). We acknowledge the National Supercomputing Center in Shenzhen for providing the computational resources and Materials Studio. AB - To deal with the problem of NO3− enrichment in water environment, electrochemical catalysis of nitrate reduction reaction (NO3RR) provides a possibility. However, this catalytic process requires efficient and highly selective NO3RR electrocatalysts to catalyze NO3− conversion. Consequently, the objective of this work is to search highly active NO3RR electrocatalysts by employing an efficient screening strategy using density functional theory methods. The catalytic activity is assessed by calculating limiting potential UL(NO3RR) and UL(HER). The research results indicate that Os2single bondC19N3 not only has excellent catalytic activity (UL(NO3RR) = −0.15 V), but also can effectively avoid the occurrence of competitive hydrogen evolution reaction. The NO3RR process of Os2single bondC19N3 is * + NO3− → *NO3 → *NO3H → NO2 → *NO2H → *NO → *NOH → *N → *NH → *NH2 → *NH3 → * + NH3. When Os2single bondC19N3 is in the condition of DFT-Sol, DFT-D, and DFT-D-Sol, the NO3RR process is * + NO3− → *NO3 → *NO3H → NO2 → *NO2H → *NO → *NOH → *NHOH → *NH2OH → *NH2 → *NH3 → * + NH3, and the UL(NO3RR) values are −0.06, −0.15, and −0.06 V, respectively. This research may offer potential reference values for the development of innovative NO3RR catalysts and the synthesis of NH3. LA - English DB - MTMT ER - TY - JOUR AU - Bulátkó, Anna AU - Shankar, Lakshmi Shiva AU - Klébert, Szilvia AU - Farkas, Attila AU - Mohai, Miklós AU - Sáfrán, György AU - Kun, Róbert AU - Nagyné László, Krisztina TI - Graphite Oxide and Reduced Graphite Oxide Models to Reveal the Contribution of Carbon Texture and Surface Chemistry to Hydrogen Storage and Li-Ion Battery Anode Performance JF - NANOMATERIALS J2 - NANOMATERIALS-BASEL VL - 16 PY - 2026 IS - 1 PG - 21 SN - 2079-4991 DO - 10.3390/nano16010019 UR - https://m2.mtmt.hu/api/publication/36842240 ID - 36842240 N1 - Funding Agency and Grant Number: National Research, Development and Innovation Office - NKFIH [OTKA K143571]; HORIZON-MSCA-2022-SE-01-01 project CLEANWATER [#101131382]; Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund [TKP2021-NVA]; Pungor Ernodblac; Scholarship of the Faculty of Chemical Technology and Biotechnology of Budapest University of Technology and Economics Funding text: We acknowledge financial support from the National Research, Development and Innovation Office - NKFIH, project ID: OTKA K143571. This work is part of the HORIZON-MSCA-2022-SE-01-01 project CLEANWATER (#101131382) and project no. TKP2021-NVA-02. The latter has been implemented with support through the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021-NVA funding scheme. A. B. is grateful for the support from the Pungor Ern & odblac; Scholarship of the Faculty of Chemical Technology and Biotechnology of Budapest University of Technology and Economics. AB - After being an indispensable intermediate in the oxidative exfoliation route towards graphene, graphene oxide has gained its deserved value in materials science for numerous applications, from catalysis, through energy storage and conversion, to sensor use. In this work, three graphene oxides of tuned morphology and chemistry are used as a simplified model for porous carbon materials in hydrogen storage and as a Li-ion battery anode. The BET surface areas were, respectively, 9, 13, and 535 m2/g, while the corresponding O/C values from the X-ray photoelectron spectroscopy were 0.51, 0.17, and 0.12. Additionally, the samples were thoroughly characterized using scanning and transmission electron imaging, powder X-ray diffraction, thermal stability, and Raman and Fourier transform infrared spectroscopic methods. Hydrogen adsorption isotherms (−196 °C) and their comparison with nitrogen uptake revealed that pore accessibility, porous confinement, and surface chemistry, i.e., both morphology and surface chemistry, contribute to efficient adsorption. In the anode application, by contrast, surface chemistry was the single most defining factor for performance. LA - English DB - MTMT ER - TY - JOUR AU - Karanja, Lucy AU - Neziri, Elsada AU - Bulátkó, Anna AU - Shan, Rong AU - Nagyné László, Krisztina AU - Szilágyi, Imre Miklós TI - Hydrothermal carbonization of spent coffee grounds: Hydrochar preparation, characterization, and adsorptive removal of rhodamine 6G JF - ENVIRONMENTAL TECHNOLOGY & INNOVATION J2 - ENVIRON TECH INNOV VL - 41 PY - 2026 PG - 20 SN - 2352-1864 DO - 10.1016/j.eti.2025.104731 UR - https://m2.mtmt.hu/api/publication/36858753 ID - 36858753 N1 - The authors sincerely thank the Stipendium Hungaricum Scholarship Program, administered by the Tempus Public Foundation, for awarding a scholarship to Lucy Nyambura Karanja to support her doctoral studies. AB - Hydrochars synthesized under different hydrothermal conditions were investigated to evaluate their structural properties and adsorption performance toward Rhodamine 6G (Rh 6G). Increasing hydrothermal temperature and residence time promoted the formation of a condensed carbon framework, consistent with progressive dehydration and aromatization. FTIR analysis revealed oxygen containing functional groups (-OH, Cdouble bondO, and Cdouble bondC), while EDX showed increasing carbon content and decreasing oxygen content with increasing hydrothermal severity. XRD patterns confirmed an amorphous structure, and nitrogen adsorption-desorption analysis indicated low BET surface areas of 2.0–4.53 m2 g−1. Batch adsorption experiments showed rapid initial uptake of Rh 6G followed by equilibrium, with removal efficiencies of 72–96 %. Adsorption kinetics followed the pseudo-second-order model (R2 = 0.991–0.9998), indicating surface-controlled adsorption. Equilibrium data fitted the Langmuir isotherm, suggesting monolayer adsorption, with maximum adsorption capacities of 299.21 ± 2.97–633.12 ± 12.17 mg g−1. Thermodynamic analysis indicated spontaneous and endothermic adsorption, with enthalpy values of 20.81–27.71 kJ mol−1 and positive entropy changes. Adsorption efficiency increased with increasing solution pH and adsorbent dosage. Post-adsorption FTIR spectra showed peak shifts and new bands, confirming surface functional group involvement in dye binding. Despite the low surface area, high adsorption performance was attributed to electrostatic attraction, π-π interactions, and hydrogen bonding. Reusability tests showed that the hydrochars retained approximately 85 % of their initial adsorption capacity after four cycles, demonstrating their potential as reusable adsorbents for dye-contaminated wastewater. LA - English DB - MTMT ER - TY - JOUR AU - Bulátkó, Anna AU - Domján, Attila AU - Balterer, Bence AU - Madarász, János AU - Nagyné László, Krisztina TI - Anomalous release of indoles from amorphous solid dispersion formed with a polymeric network JF - JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY J2 - J THERM ANAL CALORIM VL - 150 PY - 2025 SP - 245 EP - 258 PG - 14 SN - 1388-6150 DO - 10.1007/s10973-024-13648-w UR - https://m2.mtmt.hu/api/publication/35467365 ID - 35467365 N1 - Published online 2024 AB - Amorphous solid dispersion (ASDs) is a technique used in the pharmaceutical industry to enhance the solubility, dissolution rate, and bioavailability of poorly soluble drugs. Polymeric materials, and recently polymer gels form and stabilize the amorphous structure by inhibiting the aggregation/precipitation of such drugs. In this work indole, 5-aminoindole and 5-hydroxyindole loaded poly (N-isopropylacrylamide) (PNIPA) hydrogels were studied. Swelling and uptake measurements, X-ray diffraction (XRD), liquid and solid phase nuclear magnetic spectroscopy (NMR) and high sensitivity differential scanning calorimetry (DSC) were applied to understand the drug – matrix interactions affecting the release. We confirmed that the hydrogel fostered the fine uniform distribution of the hydrophobic probe molecules and successfully prevented any crystalline or amorphous phase formation during water removal, leading to a glassy solution, a special form of ASD. Despite the limited difference between their chemical composition the probe molecules showed dissimilar drug release behavior from dried loaded gel disks. While Nuclear Overhauser Enhancement Spectroscopy (NOESY) measurements revealed a “bidental” interaction between 5-hydroxiindole and the polymer, no localized interactions were found for indole. The release of the bidentally linked derivatives is rapid and complete: they act as molecular spacers, promoting the rehydration of the chains. In contrast, part of the indole remains irreversibly trapped being confined between the chains without any orientation, shedding light on the role of the steric consequences of the interaction. Our findings also indicate that such drug delivery compositions should be treated as ternary systems (carrier + drug + liquid) already in the design stages of drug release systems. © The Author(s) 2024. LA - English DB - MTMT ER - TY - JOUR AU - SHIVA SHANKAR, LAKSHMI AU - Samaniego Andrade, Samantha Kathiuska AU - Nagyné László, Krisztina AU - Pászti, Zoltán AU - Balázsi, Katalin AU - Czigány, Zsolt AU - Illés, Levente AU - Kun, Róbert TI - Corrigendum to “A fresh perspective to synthesizing and designing carbon/sulfur composite cathodes using supercritical CO2 technology for advanced Li-S battery cathodes” [J. Alloy. Compd. 1008 (2024) 176691] (Journal of Alloys and Compounds (2024) 1008, (S092583882403278X), (10.1016/j.jallcom.2024.176691)) JF - JOURNAL OF ALLOYS AND COMPOUNDS J2 - J ALLOY COMPD VL - 1010 PY - 2025 PG - 1 SN - 0925-8388 DO - 10.1016/j.jallcom.2024.177436 UR - https://m2.mtmt.hu/api/publication/35629559 ID - 35629559 AB - The authors regret that the institutional affiliation of two research fellows appearing in the acknowledgements is incorrectly listed in the first paragraph of this section. In reference to the following publication, as the corresponding author on behalf of all co-authors I would like to kindly request a corrigendum to the acknowledgements section. We kindly ask that the following correction be made to the acknowledgements paragraph of the aforementioned article. The authors thank Prof. Edit Szekely (Head of the Research Group of Supercritical Fluids, Department of Chemical and Environmental Process Engineering, Budapest University of Technology and Economics) and Dr. Marton Korosi (Research Group of Supercritical Fluids, Department of Chemical and Environmental Process Engineering, Budapest University of Technology and Economics) for their continuous professional support and helpful technical and scientific discussions on the utilization of supercritical fluids and for providing us the experimental equipment to perform our high-pressure experiments. The authors thank Tamas Szabo, Department of Physical Chemistry and Materials Science, University of Szeged, for experimental support. The authors thank the financial support from Project No. RRF-2.3.1- 21-2022-00009, titled National Laboratory for Renewable Energy that has been implemented with the support provided by the Recovery and Resilience Facility of the European Union within the framework of Programme Széchenyi Plan Plus. This research was supported by the grant no. VEKOP-2.3.3-15-2016-00002 and VEKOP-2.3.2-16-2016- 00011 of the European Structural and Investment Funds. The authors would like to apologise for any inconvenience caused. © 2024 The Authors LA - English DB - MTMT ER - TY - JOUR AU - Papp, Vanda AU - Ardelean, Ioan AU - Bulátkó, Anna AU - Nagyné László, Krisztina AU - Csík, Attila AU - Janovics, Róbert AU - Kéri, Mónika TI - Effect of metakaolin and fly ash on the early hydration and pore structure of Portland cement JF - CEMENT AND CONCRETE RESEARCH J2 - CEMENT CONCRETE RES VL - 196 PY - 2025 PG - 15 SN - 0008-8846 DO - 10.1016/j.cemconres.2025.107928 UR - https://m2.mtmt.hu/api/publication/36152966 ID - 36152966 N1 - The research was supported by the National Research, Development and Innovation Office – NKFIH [PD 135169, K 131989]. Project no. C1762343 [RH/322-2/2022] has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the KDP-2021 funding scheme. The research was also supported by the University of Debrecen Scientific Research Bridging Fund (DETKA) and by the University of Debrecen Program for Scientific Publication. Furthermore, M.K. is grateful for the support from the János Bolyai Research Scholarship of the Hungarian Academy of Sciences. The research is part of project no. BME-NVA-02, implemented with the support of the Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund, and financed under the TKP2021 funding scheme. We are grateful to István Bányai and Mihai Marius Rusu for the useful discussions and suggestions. AB - Substituting cement with pozzolans is important for various applications, like radioactive waste management. In this study, 10–30 % metakaolin and fly ash were added to Portland cement to gain insight into their effects on the structure formation, pore structure, and surface properties of cement. Early hydration of these composites was monitored using NMR relaxometry, showing that metakaolin exhibited pozzolanic activity after 8 h, while filler effect was observed for fly ash. FFC NMR and T1-T2 correlation relaxometry revealed stronger water-solid interaction for the composites compared to pure cement. The dominance of the CSH gel pores increased with the additives in dry and wet state. Water diffusion in the capillary pores, followed by H2O-D2O exchange, was slower in metakaolin composites than in fly ash containing samples. The novel combination of NMR, SEM and N2 porosimetry showed an advantage of metakaolin additive over fly ash for the long-term safe disposal of radioactive waste. LA - English DB - MTMT ER - TY - JOUR AU - Kiss, Etelka AU - Bulátkó, Anna AU - Kozma, József AU - Homokiné Krafcsik, Olga AU - Kubinyi, Miklós AU - Kamarás, Katalin AU - Nagyné László, Krisztina TI - Binding characteristics of fluorescent probes to pillararene modified graphene oxide nanosheets and their implications for indicator displacement assays JF - COLLOIDS AND SURFACES A : PHYSICOCHEMICAL AND ENGINEERING ASPECTS J2 - COLLOID SURFACE A VL - 723 PY - 2025 PG - 12 SN - 0927-7757 DO - 10.1016/j.colsurfa.2025.137341 UR - https://m2.mtmt.hu/api/publication/36166414 ID - 36166414 AB - Fluorescent indicator displacement (FID) assays in which the macrocyclic host is grafted to a graphenic material have the advantage that they operate in turn-on mode, utilizing the FRET-type quenching of the graphenic component. As a contribution to the development of such sensors, we investigated the binding of a cationic and an anionic fluorescent probe, Oxazine 1 and Pyranine (HPTS) to a hybrid nanomaterial rGO-AP6 obtained by attaching a cationic pillar[6]arene (AP6) to reduced graphene oxide (rGO). The solid-state characteristics of this nanomaterial were unveiled using FT-IR, Raman and XP spectroscopy, while its properties in aqueous suspensions were investigated by UV-Vis, fluorescence and Zeta potential measurements. The binding of the two probes was investigated by adsorption studies at pH 6.4 and 10.2, using samples of low concentrations applicable in FID assays. It was found that rGO-AP6 binds HPTS strongly whereas the adsorption of OX is below the detection limit, which is opposite to the trend shown by the unmodified rGO adsorbent. The binding affinity of rGO-AP6 for HPTS could be tuned changing the pH. The AP6 units on the surface of rGO nanosheets proved to be closely homogenous binding sites for this anionic probe. These properties make the supramolecular system HPTS/rGO-AP6 a promising candidate as a fluorescent sensor for appropriate anionic biomolecules like ATP and other nucleotides. In general, the findings of this study underscore the considerable potential of modified rGO nanosheets as platforms for FID sensors. LA - English DB - MTMT ER - TY - JOUR AU - Fekete-Kertész, Ildikó AU - Nagyné László, Krisztina AU - Bulátkó, Anna AU - Gyarmati, Benjámin Sándor AU - Molnár, Zoltán AU - Molnár, Mónika TI - Assessing the Chronic Environmental Risk of Graphene Oxide Using a Multimarker Approach Across Three Trophic Levels of the Aquatic Ecosystem JF - NANOMATERIALS J2 - NANOMATERIALS-BASEL VL - 15 PY - 2025 IS - 20 PG - 16 SN - 2079-4991 DO - 10.3390/nano15201553 UR - https://m2.mtmt.hu/api/publication/36385733 ID - 36385733 N1 - This research was funded by the Hungarian National Scientific Research Programmes OTKA K_143571 and OTKA PD_146326. This research was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences (BO/00276/25). This work is part of the HORIZON-MSCA-2022-SE-01-01 project CLEANWATER (#101131382). Project no. TKP2021-EGA-02 has been implemented with support through the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund. AB - With the rapid increase in the synthesis and application of graphene oxide (GO), questions have emerged about its inadvertent entry into aquatic habitats and the ecological consequences associated with such exposure While several studies have addressed the acute effects of GO, knowledge on its chronic impacts across multiple trophic levels remains limited. In this study, we assessed the chronic toxicity of a well-characterized GO product using model organisms representing three trophic levels: the bioluminescent marine bacterium Aliivibrio fischeri, unicellular green algae (Chlamydomonas reinhardtii, Chlorella vulgaris, Desmodesmus subspicatus), the cyanobacterium Synechococcus elongatus, and the freshwater cladoceran Daphnia magna. Endpoints included bioluminescence inhibition in bacteria, growth inhibition in photosynthetic primary producers, and reproduction and refined physiological parameters (heart rate, feeding activity) in D. magna. Our results demonstrated clear concentration-dependent chronic effects of GO, with A. fischeri, the applied photosynthetic primary producers and D. magna exhibiting significant inhibition of bioluminescence, growth, delayed onset of reproduction, and reduced fitness parameters, respectively. Based on the collected data, a comprehensive ecotoxicological risk assessment was carried out, revealing that pristine GO may pose negligible hazard to aquatic ecosystems under environmentally relevant exposure scenarios. The outcomes clearly demonstrate the relevance of incorporating chronic and multi-trophic effects when evaluating the ecological risks of emerging nanomaterials such as GO. LA - English DB - MTMT ER - TY - JOUR AU - Bulátkó, Anna AU - Höfler, Lajos AU - Kéri, Mónika AU - Majzik, Tamás István AU - Mohai, Miklós Péter AU - Sáfrán, György AU - Sebestyén, Zoltán AU - Nagyné László, Krisztina TI - Role of texture and surface chemistry in interaction of graphene oxides with water JF - JOURNAL OF MOLECULAR LIQUIDS J2 - J MOL LIQ VL - 438 PY - 2025 PG - 12 SN - 0167-7322 DO - 10.1016/j.molliq.2025.128722 UR - https://m2.mtmt.hu/api/publication/36435597 ID - 36435597 AB - Hydrophilic graphene oxide (GO) has deservedly attained wide recognition in materials science. Its hydrophilic character, which facilitates its processability, opens new avenues in a wide range of applications. In membranes employed in water treatment or in electrical devices, for example, the solid surface – water interaction plays a key role in its performance. Major characteristic features of graphene that are sacrificed during wet exfoliation were at least partially restored by a mild thermal and green chemical reduction process to yield two reduced GOs with significantly different textures but apparently similar chemical composition. The samples were comprehensively characterised with multiple techniques including microscopic imaging, N2 adsorption, powder X-ray diffraction, Raman and X-ray photoelectron spectroscopy. To reveal how the textural and chemical differences observed in “dry” conditions are manifested in the presence of water, the samples were exposed to water in the vapor and liquid state, respectively. The results reveal a synergy of surface chemistry and relative humidity. In contact with liquid water the pore texture overcomes the effect of surface chemistry in the melting/freezing transition, while surface chemistry dominates the surface charge and thus the performance against charged dissolved species: lower O/C ratios lead to higher pHPZC. Electrochemical impedance spectroscopy reveals that samples with a high concentration of surface functional groups are more efficient in reducing charge transfer resistance. These findings show the importance of controlling the reduction method to optimize the performance of graphite oxide-based materials in an aqueous environment. © 2025 Elsevier B.V., All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - Fekete-Kertész, Ildikó AU - Hajdinák, Péter AU - Nagyné László, Krisztina AU - Bulátkó, Anna AU - Podhragyai, Viktor AU - Gyarmati, Benjámin Sándor AU - Molnár, Zoltán AU - Molnár, Mónika TI - Pre-Experimental Wet Heat Sterilization Alters the Ecotoxicity of Pristine Graphene Oxide Toward Daphnia magna JF - NANOMATERIALS J2 - NANOMATERIALS-BASEL VL - 15 PY - 2025 IS - 23 PG - 21 SN - 2079-4991 DO - 10.3390/nano15231800 UR - https://m2.mtmt.hu/api/publication/36467741 ID - 36467741 N1 - This research was funded by the Hungarian National Scientific Research Programmes OTKA K_143571 and OTKA PD_146326. This research was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences (BO/00276/25). This work is part of the HORIZON-MSCA-2022-SE-01-01 project CLEANWATER (#101131382). Project no. TKP2021-EGA-02 has been implemented with support through the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund. AB - As the exposure of the aquatic ecosystem to graphene oxide (GO) increases with its growing production and use, understanding the structure–property–toxicity relationships becomes increasingly critical in the development of effective safe design guidelines. An appropriate testing methodology is crucial in ecotoxicity assessments to accurately characterize the environmentally relevant toxicity of nanoparticles, particularly for GO, where the physicochemical properties fundamentally determine their interactions and toxicity toward aquatic organisms. Many ecotoxicological methods require the heat sterilization of samples as a preliminary treatment prior to analysis. To investigate changes in toxicity profiles induced by wet heat sterilization pretreatments (autoclaving and Tyndall treatment) of a well-characterized GO product, a comprehensive ecotoxicological evaluation was performed with Daphnia magna. This included conventional lethality and immobilization tests, along with sublethal endpoints such as heart rate and feeding activity, supplemented with the analysis of oxidative stress biomarkers. Physicochemical alterations in GO due to sterilization were examined with dynamic light scattering, ultraviolet-visible, and thermogravimetry/mass spectrometry. Sublethal endpoints were shown to be more sensitive indicators of toxicity than conventional methods, with feeding activity and heart rate inhibition demonstrating time and concentration-dependent effects. Heat-sterilized GOs exhibited greater ecotoxicity compared to pristine GO, as evidenced by elevated ROS levels and increased oxidative stress biomarkers (GPx and GST activities), implicating oxidative stress as a central mechanism of toxicity. Despite the subtle differences observed in the physicochemical properties, the impact of heat sterilization on toxicity is clear. Our research underscores the critical importance of adopting appropriate testing and evaluation methodologies for comparing GO ecotoxicity results under axenic and non-axenic conditions as well as a multimarker approach to accurately evaluate the risks posed by GO. LA - English DB - MTMT ER -