Publications by authors named "Kukovecz A"

Article Synopsis
  • Barium titanate photocatalysts were created using a low-cost sol-gel method with a specific calcination technique involving rapid heating; they were analyzed using several characterization techniques.
  • The photocatalysts demonstrated low photooxidation activity for degrading pollutants like phenol and chlorophenol but exhibited high photoreduction activity for CO conversion, outperforming commercial references.
  • The unique calcination method proved to be 29.5% more cost-effective than traditional techniques and allowed for a larger yield of barium titanate with the same energy input.
View Article and Find Full Text PDF

Desilication products (DSPs) are one of the main components of bauxite residue, which is currently discharged without further usage. The present study reports on the use of DSPs as adsorbents for basic fuchsine dye. Using artificial spent liquor, we synthesized not only neat DSP but also solids in the presence of various organics, to account for their likely occurrence during the Bayer process.

View Article and Find Full Text PDF

Surface modification, including the anchoring of functional groups is a popular method to increase the photocatalytic activity of semiconductor photocatalysts. These species can trap excited electrons, thus prolonging the life of the charge carriers. N-containing functional groups are suitable for this purpose due to their high electron density.

View Article and Find Full Text PDF
Article Synopsis
  • Researchers used a co-precipitation method to integrate the sunscreen ingredient sulisobenzone into the structure of a hybrid material known as CaFe-hydrocalumite for the first time.
  • They employed various techniques like X-ray diffraction and spectroscopy to analyze the effects of mechanical milling on the material's properties, revealing noticeable changes in structure, surface characteristics, and thermal behavior.
  • Notably, milling enhanced the UV light blocking ability of the material, particularly around 320 nm, due to changes in the interactions between the sulfobenzone anions and the layers of the hydrocalumite structure.
View Article and Find Full Text PDF

Liquid phase direct amination of phenols to primary anilines with hydrazine was achieved using commercial NiLa-perovskite catalysts as bifunctional Lewis acid/redox-active catalysts without adding any external hydride sources. The amination strategy took place efficiently in the absence of any amount of reducing gasses (H/NH) and noble metals under mild conditions.

View Article and Find Full Text PDF

Calcium titanate (CTO) photocatalysts were synthesized using a sol-gel method by adopting a cost-efficient, rapid calcination technique. The CTOs were characterized by X-ray diffractometry, X-ray photoelectron spectroscopy, infrared spectroscopy, nitrogen adsorption, porosimetry measurements, scanning/transmission electron microscopy, and diffuse reflectance spectroscopy. Their photocatalytic activity was assessed through the photocatalytic degradation of phenol, oxalic acid, and chlorophenol under UV light exposure, using a commercial CTO as a reference.

View Article and Find Full Text PDF

Herein, we investigate the potential of nanostructured high-entropy oxides (HEOs) for photocatalytic CO hydrogenation, a process with significant implications for environmental sustainability and energy production. Several cerium-oxide-based rare-earth HEOs with fluorite structures were prepared for UV-light driven photocatalytic CO hydrogenation toward valuable fuels and petrochemical precursors. The cationic composition profoundly influences the selectivity and activity of the HEOs, where the CeZrLaNdSmO catalyst showed outstanding CO activation (14.

View Article and Find Full Text PDF

Different Co contents were used to tune bimetallic Pt-Co nanoparticles with a diameter of 8 nm, resulting in Pt:Co ratios of 3.54, 1.51, and 0.

View Article and Find Full Text PDF

The presence of alkaline earth cations, in particular, Ca and Mg ions in brine, causes undesired effects in solutions containing anionic surfactants because of precipitate formation. In the present study, an anionic surfactant, sodium dodecyl sulfate (SDS), was investigated, focusing on the determination of various properties (surface tension, critical micelle concentration, micelle size, turbidity) in the presence of alcohols and, in particular, the inhibition of the precipitation of SDS with calcium ions. The calcium ions were added to the surfactant in increasing concentrations (3.

View Article and Find Full Text PDF

CeNiO has been reported in the literature in the last few years as a novel LnNiO compound with promising applications in different catalytic fields, but its structure has not been correctly reported so far. In this research, CeNiO (RB1), CeO and NiO have been synthesized in a nanocrystalline form using a modified citrate aqueous sol-gel route. A direct comparison between the equimolar physical mixture ((CeO) : (NiO) = 1 : 1) and compound RB1 was made.

View Article and Find Full Text PDF

The implementation of supported metal catalysts heavily relies on the synergistic interactions between metal nanoparticles and the material they are dispersed on. It is clear that interfacial perimeter sites have outstanding skills for turning catalytic reactions over, however, high activity and selectivity of the designed interface-induced metal distortion can also obtain catalysts for the most crucial industrial processes as evidenced in this paper. Herein, the beneficial synergy established between designed Pt nanoparticles and MnO in the course of the reverse water gas shift (RWGS) reaction resulted in a Pt/MnO catalyst having ≈10 times higher activity compared to the reference Pt/SBA-15 catalyst with >99 % CO selectivity.

View Article and Find Full Text PDF

Hypothesis: Reduced graphene oxide (rGO/polycation/sulfur) composites are promising cathode materials for Li-S battery applications because homogeneously dispersed sulfur nano/micro clusters in suitable carbon hosts enable remarkable cycle life for Li-S battery cells. New, benign and economic synthesis methods based only on aqueous colloidal dispersions are demanded for achieving high dispersity grade of sulfur within the carbon host. Colloidal interactions leading to heteroaggregation between carbonaceous lamellae and polycation-modified sulphur nanoparticles at ambient conditions in water are foreseen to afford nanocomposite cathodes, which maintain excellent electrochemical performance.

View Article and Find Full Text PDF

Certain industrially relevant performance metrics of CO electrolyzers have already been approached in recent years. The energy efficiency of CO electrolyzers, however, is yet to be improved, and the reasons behind performance fading must be uncovered. The performance of the electrolyzer cells is strongly affected by their components, among which the gas diffusion electrode is one of the most critical elements.

View Article and Find Full Text PDF

Anionic surfactants, such as sodium linear alkylbenzene sulfonates (NaLAS), are utilized in various fields, including industry, household, and agriculture. The efficiency of their use in aqueous environments is significantly affected by the presence of cations, Ca and Mg in particular, as they can decrease the concentration of the surfactant due to precipitation. To understand cation-sulfonate interactions better, we study both NaLAS colloidal solutions in the presence of CaCl and precipitates forming at higher salt concentrations.

View Article and Find Full Text PDF

Dentitions of the sympatric herbivorous dinosaurs Hungarosaurus (Ankylosauria, Nodosauridae) and Mochlodon (Ornithopoda, Rhabdodontidae) (Santonian, Hungary) were analysed to investigate their dietary ecology, using several complementary methods-orientation patch count, tooth replacement rate, macrowear, tooth wear rate, traditional microwear, and dental microwear texture analysis (DMTA). Tooth formation time is similar in Hungarosaurus and Mochlodon, and traditional and DMTA microwear features suggest low-browsing habits for both taxa, consistent with their inferred stances and body sizes. However, Mochlodon possesses a novel adaptation for increasing dental durability: the dentine on the working side of the crown is double the thickness of that on the balancing side.

View Article and Find Full Text PDF

Tannic acid (TA) and glutathione (GSH) are important molecular antioxidants against reactive oxygen species. Their efficiency is limited by low solubility and high sensitivity, which may be solved by confinement in composite materials. Here, effect of immobilization of these antioxidants on their radical scavenging activity was investigated using layered double hydroxide (LDH) nanoparticles as hosts.

View Article and Find Full Text PDF

The quantitative analysis of datasets achieved by single molecule localization microscopy is vital for studying the structure of subcellular organizations. Cluster analysis has emerged as a multi-faceted tool in the structural analysis of localization datasets. However, the results it produces greatly depend on the set parameters, and the process can be computationally intensive.

View Article and Find Full Text PDF

In this study, clay composites were subjected to electromagnetic transmission testing at frequencies in the region of non-ionizing radiation. Specimens were made with partial substitution of clay with different admixtures by mass. Admixtures used were Fly Ash, four different particle sizes and phases of Titanium Dioxide (TiO), Zinc Ferrite (ZnFeO), Maghemite (γ-FeO) and Antimony Tin Oxide (ATO).

View Article and Find Full Text PDF

Filtering facepiece respirators (FFRs) provide effective protection against diseases spread through airborne infectious droplets and particles. The widespread use of FFRs during the COVID-19 pandemic has not only led to supply shortages, but the disposal of single-use facemasks also threatens the environment with a new kind of plastic pollution. While limited reuse of filtering facepiece respirators has been permitted as a crisis capacity strategy, there are currently no standard test methods available for decontamination before their repeated use.

View Article and Find Full Text PDF

Fossil bioinclusions in amber are invaluable source of information on the past evolution and diversity of various organisms, as well as on the paleoecosystems in general. The click-beetles, Elateridae, which originated and greatly diversified during the Mesozoic, are mostly known from the adpression-like fossils, and their diversity in the Cretaceous ambers is only poorly documented. In this study, we describe a new click-beetle based on an incomplete inclusion in ajkaite, an Upper Cretaceous (Santonian) amber from the Ajka Coal Formation from Hungary.

View Article and Find Full Text PDF

HS is a toxic and corrosive gas, whose accurate detection at sub-ppm concentrations is of high practical importance in environmental, industrial, and health safety applications. Herein, we propose a chemiresistive sensor device that applies a composite of single-walled carbon nanotubes (SWCNTs) and brominated fullerene (CBr) as a sensing component, which is capable of detecting 50 ppb HS even at room temperature with an excellent response of 1.75% in a selective manner.

View Article and Find Full Text PDF

Efficient Lewis-acid-catalyzed direct conversion of aldehydes to 1,2-diketones in the liquid phase was enabled by using newly designed and developed ceria-zirconia-based high-entropy oxides (HEOs) as the actual catalysts. The synergistic effect of various cations incorporated in the same oxide structure (framework) was partially responsible for the efficiency of multicationic materials compared to the corresponding single-cation oxide forms. Furthermore, a clear, linear relationship between the Lewis acidity and the catalytic activity of the HEOs was observed.

View Article and Find Full Text PDF

Soft materials such as gels or biological tissues can develop self-assembly under chemo-mechanical forces. Here, we report the instantaneous formation of soft tubular structures with a two-level hierarchy by injecting a mixture of inorganic salt and chitosan (CS) solution from below into a reactor filled with alkaline solution. Folding and wrinkling instabilities occur on the originally smooth surface controlled by the salt composition and concentration.

View Article and Find Full Text PDF

The synthesis of the copper-poor and aluminum-rich layered double hydroxides (LDHs) of the CuAl type was optimized in detail in this work, by applying an intense mechanochemical treatment to activate the gibbsite starting reagent. The phase-pure forms of these LDHs were prepared for the first time; using copper nitrate and perchlorate salts during the syntheses turned out to be the key to avoiding the formation of copper hydroxide sideproducts. Based on the use of the optimized syntheses parameters, the preparation of layered triple and multiple hydroxides was also attempted using Ni(II), Co(II), Zn(II) and even Mg(II) ions.

View Article and Find Full Text PDF
Article Synopsis
  • A layered self-supported Cu(II)Bi(III) bimetallic catalyst was developed, featuring a Sillen-type bismutite framework with copper(II) ions as guests.
  • This heterogeneous catalyst efficiently promoted C-N and C-S arylations under mild conditions, achieving high selectivity and a range of substrate compatibility, which is valuable for producing phenothiazines.
  • Detailed studies confirmed the catalyst's cooperative mechanism, allowed for multiple recyclings without losing structural integrity or activity.
View Article and Find Full Text PDF