TY - JOUR AU - Fazekas, Ákos Ferenc AU - Gyulavári, Tamás AU - Ágoston, Áron AU - Janovák, László AU - Heszlerné Kopniczky, Judit AU - László, Zsuzsanna AU - Veréb, Gábor TI - Enhanced Photocatalytic and Filtration Performance of TiO2-Ag Composite-Coated Membrane Used for the Separation of Oil Emulsions JF - SEPARATIONS J2 - SEPARATIONS VL - 11 PY - 2024 IS - 4 SP - 112 SN - 2297-8739 DO - 10.3390/separations11040112 UR - https://m2.mtmt.hu/api/publication/34823133 ID - 34823133 AB - Polyvinylidene fluoride (PVDF) membranes were coated with TiO2 and TiO2-Ag to enhance their efficiency for oil-in-water emulsion separation. The photocatalytic activities of the two modified membranes and their filtration performances were compared in detail. The significantly enhanced photocatalytic activity of the TiO2-Ag composite was proved using a methyl orange (MO) solution (c = 10−5 M) and a crude oil emulsion (c = 50 mg·L−1). The TiO2-Ag-coated membrane reduced the MO concentration by 87%, whereas the TiO2-modified membrane reached only a 46% decomposition. The photocatalytic reduction in the chemical oxygen demand of the emulsion was also ~50% higher using the TiO2-Ag-coated membrane compared to that of the TiO2-coated membrane. The photoluminescence measurements demonstrated a reduced electron/hole recombination, achieved by the Ag nanoparticle addition (TiO2-Ag), which also explained the enhanced photocatalytic activity. A significant improvement in the oil separation performance with the TiO2-Ag-coated membrane was also demonstrated: a substantial increase in the flux and flux recovery ratio (up to 92.4%) was achieved, together with a notable reduction in the flux decay ratio and the irreversible filtration resistance. Furthermore, the purification efficiency was also enhanced (achieving 98.5% and 99.9% COD and turbidity reductions, respectively). Contact angle, zeta potential, scanning electron microscopy (SEM), and atomic force microscopy (AFM) measurements were carried out to explain the results. SEM and AFM images revealed that on the TiO2-Ag-coated membrane, a less aggregated, more continuous, homogeneous, and smoother nanolayer was formed due to the ~50% more negative zeta potential of the TiO2-Ag nanocomposite compared to that of the TiO2. In summary, via Ag addition, a sufficiently hydrophilic, beneficially negatively charged, and homogeneous TiO2-Ag-coated PVDF membrane surface was achieved, which resulted in the presented advantageous filtration properties beyond the photocatalytic activity enhancement. LA - English DB - MTMT ER - TY - JOUR AU - Mészáros, Rebeka Ildikó AU - Szabó, Vivien AU - Kutus, Bence AU - Baán, Kornélia AU - Kónya, Zoltán AU - Kukovecz, Ákos AU - Sipos, Pál Miklós AU - Szabados, Márton TI - Continuous-flow hydrogenation of cinnamaldehyde over catalysts derived from modified CoAl4 layered double hydroxides incorporating Mn, Ni, Cu and Zn ions JF - APPLIED CATALYSIS A-GENERAL J2 - APPL CATAL A-GEN VL - 679 PY - 2024 PG - 14 SN - 0926-860X DO - 10.1016/j.apcata.2024.119738 UR - https://m2.mtmt.hu/api/publication/34801853 ID - 34801853 LA - English DB - MTMT ER - TY - JOUR AU - Nánai, Lilla AU - Németh, Zoltán AU - Kaptay, György AU - Hernádi, Klára TI - Experimental and theoretical aspects of the growth of vertically aligned CNTs by CCVD on AZO substrate JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 14 PY - 2024 IS - 1 SN - 2045-2322 DO - 10.1038/s41598-024-57862-w UR - https://m2.mtmt.hu/api/publication/34762909 ID - 34762909 AB - An efficient and reproducible growth of vertically aligned carbon nanotubes by CCVD requires accurate and specific setting of the synthesis parameters and the properties of catalyst thin layers. In this work, the growth of vertically aligned carbon nanotubes onto AZO (= aluminum doped zinc oxide) glass substrate covered by Al 2 O 3 and Fe-Co catalyst layer system is presented. Investigation of the effect of catalyst composition and synthesis temperature on CVD growth revealed the optimum condition of the synthesis. The analysis of as-prepared samples by SEM, TEM and Raman spectroscopy was carried out to prove the structure and quality of carbon deposit. Theoretical considerations have supported speculative ideas about the role of the support layer, the transformation of the catalyst layer in the presence of hydrogen gas and the growth mechanism of carbon nanotubes. The mechanism of CNT growth is modelled and the order of magnitude of experimentally observed vertical linear growth rate of CNT (several nm/s) is reproduced. LA - English DB - MTMT ER - TY - JOUR AU - Papp, Paszkál AU - Tóth, Ágota AU - Horváth, Dezső TI - Population Mass Balance Model for Precipitation with Turbidity Measurements JF - ACS OMEGA J2 - ACS OMEGA VL - 9 PY - 2024 IS - 11 SP - 13412 EP - 13417 PG - 6 SN - 2470-1343 DO - 10.1021/acsomega.3c10516 UR - https://m2.mtmt.hu/api/publication/34728312 ID - 34728312 LA - English DB - MTMT ER - TY - JOUR AU - El Aouni, Aicha AU - El Ouardi, Mohamed AU - Arab, Madjid AU - Saadi, Mohamed AU - Haspel, Henrik AU - Kónya, Zoltán AU - Ben Ali, Abdelkader AU - Jada, Amane AU - BaQais, Amal AU - Ait Ahsaine, Hassan TI - Design of Bismuth Tungstate Bi2WO6 Photocatalyst for Enhanced and Environmentally Friendly Organic Pollutant Degradation JF - MATERIALS J2 - MATERIALS VL - 17 PY - 2024 IS - 5 SP - 1029 SN - 1996-1944 DO - 10.3390/ma17051029 UR - https://m2.mtmt.hu/api/publication/34688462 ID - 34688462 AB - In this study, a chemical precipitation approach was adopted to produce a photocatalyst based on bismuth tungstate Bi2WO6 for enhanced and environmentally friendly organic pollutant degradation. Various tools such as X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), optical spectroscopy and X-ray photoelectron spectroscopy, were employed to assess the structural and morphological properties. Hence, the XRD profiles showed a well crystallized Bi2WO6 orthorhombic phase. The photocatalytic performance of the resulting photocatalyst was assessed by the decomposition of Rhodamine B (RhB) and methyl orange (MO) with a decomposition efficiency of 97 and 92%, along with the highest chemical oxygen demand of 82 and 79% during 120 min of illumination, respectively. The principal novelty of the present work is to focus on the changes in the crystalline structure, the morphology, and the optical and the photoelectrochemical characteristics of the Bi2WO6, by tuning the annealing temperature of the designed photocatalyst. Such physicochemical property changes in the as-prepared photocatalyst will affect in turn its photocatalytic activity toward the organic pollutant decomposition. The photocatalytic mechanism was elaborated based on electrochemical impedance spectroscopy, photocurrent analysis, photoluminescence spectroscopy, and radical trapping measurements. The overall data indicate that the superoxide O2•− and holes h+ are the principal species responsible for the pollutant photodegradation. LA - English DB - MTMT ER - TY - JOUR AU - Rónavári, Andrea AU - Ochirkhuyag, Altantuya AU - Igaz, Nóra AU - Szerencsés, Bettina AU - Ballai, Gergő AU - Huliák, Ildikó AU - Bocz, Csenge AU - Kovács, Ákos AU - Pfeiffer, Ilona AU - Csontné Kiricsi, Mónika AU - Kónya, Zoltán TI - Preparation, characterization and in vitro evaluation of the antimicrobial and antitumor activity of MnOx nanoparticles JF - COLLOIDS AND SURFACES A : PHYSICOCHEMICAL AND ENGINEERING ASPECTS J2 - COLLOID SURFACE A VL - 688 PY - 2024 SN - 0927-7757 DO - 10.1016/j.colsurfa.2024.133528 UR - https://m2.mtmt.hu/api/publication/34687262 ID - 34687262 LA - English DB - MTMT ER - TY - JOUR AU - Varga, Gábor AU - Nguyen, Thanh-Truc AU - Wang, Jing AU - Tian, Dihua AU - Zhang, Run AU - Li, Li AU - Xu, Zhi Ping TI - Isomorphic Insertion of Ce(III)/Ce(IV) Centers into Layered Double Hydroxide as a Heterogeneous Multifunctional Catalyst for Efficient Meerwein–Ponndorf–Verley Reduction JF - ACS APPLIED MATERIALS & INTERFACES J2 - ACS APPL MATER INTER VL - 16 PY - 2024 IS - 9 SP - 11453 EP - 11466 PG - 14 SN - 1944-8244 DO - 10.1021/acsami.3c16732 UR - https://m2.mtmt.hu/api/publication/34685180 ID - 34685180 AB - The development of highly active acid-base catalysts for transfer hydrogenations of biomass derived carbonyl compounds is a new, pressing challenge. Solid Frustrated Lewis Pairs (FLP) catalysis is possibly a solution but the development of this concept is still at a very early stage. Herein, by inserting Ce(III)/Ce(IV) centers into layered double hydroxide (MgAlCe–LDH), effective, selective and recyclable solid acid-base catalysts were synthesized, which enabled efficient transfer hydrogenation (MPV reduction) of biomass derived carbonyl compounds to corresponding alcohols. The cooperative, FLP-like interplay between the active sites of Ce(III)/Ce(IV) and the aluminum-containing defect sites formed by the incorporation of cerium into the lattice of LDH is necessary to maximize the catalytic efficiency. Furthermore, the crucial role of the surface hydroxyl groups in the MPV reactions and the negative impact of the interlamellar/adsorbed water molecules on the catalytic activity of MgAlCe-LDH were demonstrated. These solid FLP-like acid-base catalysts exhibited excellent catalytic performance (cyclohexanol yield of 45%; furfuryl alcohol yield of 51%), which is competitive or superior to the benchmark, Sn- and Zr-containing zeolite catalysts, under mild reaction conditions, especially low temperature (T = 65°C in the case of cyclohexanol production). Our research has indicated that Ce-containing LDH is a potentially commercial solid FLP catalysts. LA - English DB - MTMT ER - TY - JOUR AU - Najari, Sara AU - Saeidi, Samrand AU - Sápi, András AU - Szamosvölgyi, Ákos AU - Papp, Ádám AU - Efremova, Anastasiia AU - Bali, Henrik AU - Kónya, Zoltán TI - Synergistic enhancement of CO2 hydrogenation to C5+ hydrocarbons using mixed Fe5C2 and Na-Fe3O4 catalysts: Effects of oxide/carbide ratio, proximity, and reduction JF - CHEMICAL ENGINEERING JOURNAL J2 - CHEM ENG J VL - 485 PY - 2024 PG - 16 SN - 1385-8947 DO - 10.1016/j.cej.2024.149787 UR - https://m2.mtmt.hu/api/publication/34646124 ID - 34646124 LA - English DB - MTMT ER - TY - JOUR AU - Takács, Tamás AU - Abdelghafour, Mohamed M. AU - Sebők, Dániel AU - Kukovecz, Ákos AU - Janovák, László TI - Structural and thermoanalytical characterization of self-healing polymer: the effect of cross-linking density JF - JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY J2 - J THERM ANAL CALORIM VL - https://doi.org/10.1007/s10973-023-12862-2 PY - 2024 SP - https://doi.org/10.1007/s10973-023-12862-2 SN - 1388-6150 DO - 10.1007/s10973-023-12862-2 UR - https://m2.mtmt.hu/api/publication/34547597 ID - 34547597 AB - The effect of the gradually formed cross-linked structure on the thermal properties and swelling behaviour of modified poly(vinyl alcohol) was investigated. To this aim, the semi-crystalline polymer was functionalized with aldehyde and amino moieties to produce polymers with dynamic imine cross-links, and, thus, with self-healing or curing ability. With increasing degree of functionalization (0.89–7.12%), denser polymer networks cross-linked by dynamic imine bonds were formed, the samples systematically developed thermoset-like properties compared to the pristine, initially thermoplastic PVA. As a result, the introduction of new moieties into the initial PVA lowered the glass transition (from 65.3 to 35.0 °C) and melting temperatures (from 194 to 161 °C), however, a new peak (T crd ) with growing enthalpy values appeared on the DSC curves, which indicates that more and more energy must be supplied in order to break the imine cross-links formed between the introduced aldehyde and amino groups. The significant impact of the degree of functionalization and cross-linking density on the polymer structure was also clearly demonstrated: the crystallinity decreased as the abundance of the introduced moieties increased and the formation of cross-links proceeded. At the same time, the water desorption enthalpies of the samples increased, suggesting a stronger, chemically cross-linked thermoset-like polymer network compared to the thermoplastic poly(vinyl alcohol). LA - English DB - MTMT ER - TY - JOUR AU - Fabrikov, Dmitri AU - Varga, Ágnes Timea AU - García, María Carmen Vargas AU - Bélteky, Péter AU - Kozma, Gábor AU - Kónya, Zoltán AU - López Martínez, Josefa L. AU - Barroso, Fernando AU - Sánchez-Muros, María José TI - Antimicrobial and antioxidant activity of encapsulated tea polyphenols in chitosan/alginate-coated zein nanoparticles: a possible supplement against fish pathogens in aquaculture JF - ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH J2 - ENVIRON SCI POLLUT R VL - 31 PY - 2024 SP - 13673 EP - 13687 PG - 15 SN - 0944-1344 DO - 10.1007/s11356-024-32058-x UR - https://m2.mtmt.hu/api/publication/34535462 ID - 34535462 AB - Regulation of antibiotic use in aquaculture calls for the emergence of more sustainable alternative treatments. Tea polyphenols (GTE), particularly epigallocatechin gallate (EGCG), have various biological activities. However, tea polyphenols are susceptible to degradation. In this work, EGCG and GTE were encapsulated in zein nanoparticles (ZNP) stabilized with alginate (ALG) and chitosan (CS) to reduce the degradation effect. ALG-coated ZNP and ALG/CS-coated ZNP encapsulating EGCG or GTE were obtained with a hydrodynamic size of less than 300 nm, an absolute ζ -potential value >30 mV, and an encapsulation efficiency greater than 75%. The antioxidant capacity of the encapsulated substances, although lower than that of the free ones, maintained high levels. On the other hand, the evaluation of antimicrobial activity showed greater efficiency in terms of growth inhibition for ALG/CS-ZNP formulations, with average overall values of around 60%, reaching an inhibition of more than 90% for Photobacterium damselae . These results support encapsulation as a good strategy for tea polyphenols, as it allows maintaining significant levels of antioxidant activity and increasing the potential for antimicrobial activity, in addition to increasing protection against sources of degradation. LA - English DB - MTMT ER -