Filtry
wszystkich: 1473
wybranych: 1213
-
Katalog
Filtry wybranego katalogu
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: graphene hydrogel
-
Wykorzystanie wiązań niekowalencyjnych do otrzymywania jedno- i dwuskładnikowych struktur supramolekularnych
PublikacjaPrzedstawiona rozprawa doktorska dotyczy badań nad wykorzystaniem oddziaływań międzycząsteczkowych do projektowania i syntezy uporządkowanych struktur krystalicznych, ze szczególnym uwzględnieniem wiązań halogenowych i chalkogenowych jako stosunkowo nowych i bardzo atrakcyjnych z punktu widzenia inżynierii kryształu. Praca podzielona jest na kilka części. Pierwsza z nich stanowi wstęp teoretyczny obejmujący opis, założenia oraz...
-
The effect of imidazolium ionic liquid on the morphology of Pt nanoparticles deposited on the surface of SrTiO3 and photoactivity of Pt–SrTiO3 composite in the H2 generation reaction
PublikacjaPhotocatalytic water splitting has great potential in solar-hydrogen production as a low-cost and environmentally friendly method. Different unique techniques used to obtain photocatalysts with various modifications to improve H2 generation have been introduced. In the present work, SrTiO3 was successfully synthesized via the solvothermal method in the presence of ionic liquid (IL) - 1-butyl-3-methylimidazolium bromide ([BMIM][Br])...
-
Propensity of salicylamide and ethenzamide cocrystallization with aromatic carboxylic acids
PublikacjaThe cocrystallization of salicylamide (2-hydroxybenzamide, SMD) and ethenzamide (2-ethoxybenzamide, EMD) with aromatic carboxylic acids was examined both experimentally and theoretically. The supramolecular synthesis taking advantage of the droplet evaporative crystallization (DEC) technique was combined with powder diffraction and vibrational spectroscopy as the analytical tools. This led to identification of eleven new cocrystals...
-
Structure and thermoelectric properties of Te/Ag/Ge/Sb (TAGS) materials obtained by reduction of melted oxide substrates
PublikacjaThe Ge0.77Ag0.1Sb0.13Te1alloy was fabricated by a novel two step route. For that purpose firstly the oxide reagents were melted at high temperature and quenched into pellets. After that pellets were milled to the powder and then reduced in hydrogen at various temperatures and for various periods of time. Energy dispersive X-ray analysis indicated the possibility of successful fabrication of stoichiometric thermoelectric materials...
-
Oxygen sensitivity of hydrogenesis’ and methanogenesis’
PublikacjaIn the chapter, results of dark fermentation of sour cabbage in presence of oxygen with concentrations 2-9% are presented. The presence of oxygen in such concentration inhibits methanogesis (and methane production more than 2 times) and increases hydrogen production 6 times. It also shortens the fermentation process above 40%.
-
Bromidotetrakis(2-ethyl-1H-imidazole-KN3)copper(II) bromide
PublikacjaThe CuII ion in the title complex, [CuBr(C5H8N2)4]Br, is coordinated in a square-pyramidal geometry by four N atoms of imidazole ligands and one bromide anion in the apical position. In the crystal, the ions are linked by a 3-D network of N-H---Br and CH---Br hydrogen bonds.
-
Napawanie elementów wymiennika ciepła austenitycznym drutem proszkowym
PublikacjaNa potrzeby przemysłu energetycznego produkuje się wymienniki ciepła przeznaczone do eksploatacji w warunkach agresywnych chemicznie, np. w środowisku siarkowodoru. Z przyczyn ekonomicznych często stosuje się w takim przypadku materiały bimetaliczne wytwarzane procesami napawania. W artykule przedstawiono wyniki badań nieniszczących, pomiarów twardości, analizy składu chemicznego, pomiarów ferrytu delta oraz badań makro- i mikroskopowych...
-
Structural and dynamic properties of water within the solvation layer around various conformations of the glycine-based polypeptide
PublikacjaSeveral conformations of the solvated glycine-based polypeptides were investigated using molecular dynamics simulations. Some properties of water in the neighbouring space around these molecules were investigated. It was found, that water forms a well-defined layer - the first solvation shell - around the peptide molecule, and thickness of this layer is independent of the peptide structure, and it equals to approximately 0.28 nm....
-
Luminescent collisions of He+ and He++ ions with H2 molecules at energies below 2 keV
PublikacjaSpectroscopic studies of collisions between He+ and He++ ions with H2 gas target have been performed in the 200–600nm wavelength range. Atomic lines of hydrogen Balmer series and several helium lines were identified and their excitation functions between 50 eV and 1keV (2keV for He++) were determined.
-
The CON−H…+NH2 Blue-Shifting H-Bond Stabilizing Effect on Z Secondary Amides and Cyclic System Conformational Rearrangement through an Alkylamine-Chain Migration Pathway
PublikacjaThe paper is focusing on the amide linkage exceptional properties and usage of chemistry (conformational rearrangement, geometrical stereoisomers, spectroscopic blue shift phenomenon, protonation and deprotonation reactions, synthetic scope, and mechanistic implications). Hydrogen-bond-stabilized acylation reactions of a diamine with thioamides or nitriles reveal how substituents influence both the outcome of stereoselectivity...
-
Photophysics of Soret-Excited Tin(IV) Porphyrins in Solution
PublikacjaThe photophysics of low-chlorin tin(IV) tetraphenylporphyrin dihydroxide, a core building block for axially substituted supramolecular tin porphyrin constructs, has been studied in a variety of hydrogen-bonding, nonpolar, and aprotic polar solvents using steady-state, nanosecond, and femtosecond time-resolved emission, and femtosecond time-resolved absorption methods. In hydrogen-bonding solvents the metalloporphyrin exists as...
-
Influence of pyrolysis atmosphere on the lithium storage properties of carbon-rich polymer derived SiOC ceramic anodes
PublikacjaPolymer derived carbon-rich SiOC ceramics are prepared from polysiloxane precursors through a pyrolysis process at 1000 °C using pure argon and argon/hydrogen mixture as pyrolysis atmosphere. The precursor is synthesized from a linear (Si–H)-containing polysiloxane cross-linked with divinylbenzene using hydrosilylation reaction in the presence of a platinum catalyst. Pyrolysis in Ar/H2 mixtures, compared to the treatment under...
-
Experimental and Machine-Learning-Assisted Design of Pharmaceutically Acceptable Deep Eutectic Solvents for the Solubility Improvement of Non-Selective COX Inhibitors Ibuprofen and Ketoprofen
PublikacjaDeep eutectic solvents (DESs) are commonly used in pharmaceutical applications as excellent solubilizers of active substances. This study investigated the tuning of ibuprofen and ketoprofen solubility utilizing DESs containing choline chloride or betaine as hydrogen bond acceptors and various polyols (ethylene glycol, diethylene glycol, triethylene glycol, glycerol, 1,2-propanediol, 1,3-butanediol) as hydrogen bond donors. Experimental...
-
Experimental and Machine-Learning-Assisted Design of Pharmaceutically Acceptable Deep Eutectic Solvents for the Solubility Improvement of Non-Selective COX Inhibitors Ibuprofen and Ketoprofen
PublikacjaDeep eutectic solvents (DESs) are commonly used in pharmaceutical applications as excellent solubilizers of active substances. This study investigated the tuning of ibuprofen and ketoprofen solubility utilizing DESs containing choline chloride or betaine as hydrogen bond acceptors and various polyols (ethylene glycol, diethylene glycol, triethylene glycol, glycerol, 1,2-propanediol, 1,3-butanediol) as hydrogen bond donors. Experimental...
-
Role of nitrogen in evolution of sp2/sp3 bonding and optical band gap in hydrogenated carbon nitride
PublikacjaDrastic changes in the bonding are found in amorphous hydrogenated carbon nitride (a-CNx:H) film as a function of nitrogen concentration (or N/C ratio). The total C-sp3 fraction and hardness shows a sharp decrease (at N/C = 0.40) whereas optical band gap and resistivity shows a gradual increase as nitrogen concentration increases from 0.07 to 0.58. Raman spectrum of a-CNx:H film is fitted with both Gaussian (integrated intensity...
-
Hydrogen-bonded one-dimensional networks in 1:1 complexes of N,N`-bis(2-pi-rydyl)aryldiamines with anilic acid. Acta Cryst. Sect. C Crystal Struct.Commun.**2002 vol. 58 s. o735-o738, 4 rys. 4 tab. bibliogr. 15 poz. Jednowymiarowe sieci krystaliczne tworzone w wyniku oddziaływań wodorowych pomiędzy N,N`-bis(2-pirydylo)aryloaminami a kwasem anilowym.
PublikacjaOtrzymano związki kompleksowe kwasu anilowego z N,N`-bis(2-pirydylo)-1,4-diaminobenzenem oraz N,N`-bis(2-pirydylo)-4,4`-diaminobifenylem o stechiometrii1:1, a następnie przeprowadzono analizę rentgenograficzną monokryształów. Wobu przypadkach cząsteczki, wchodzące w skład kompleksu są powiązane ze sobąkonwencjonalnymi oddziaływaniami wodorowymi. Tym samym tworzy się jednowy-miarowa sieć krystaliczna z dziewięcioczłonowym pierścieniowym...
-
(1H-Pyrazole-[kappa]N)bis(tri-tert-butoxysilanethiolato-[kappa]2O,S)cadmium
PublikacjaThe CdII atom in the title complex, [Cd(C12H27O3SSi)2-(C3H4N2)], is penta-coordinated by two O and two S atoms from the O,S-chelating silanethiolate residue and one pyrazole N atom in a distorted trigonal-bipyramidal geometry. The pyrazole ligand forms an intramolecular N-H---O hydrogen bond.
-
Rigid polyurethane foams with different flame retardants and their physical and mechanical properties
PublikacjaRigid polyurethane foams (PUFs) containing 3, 6 or 9 % of one of of two selected fire retardants (FR): oligomeric ethyl ethylene phosphate (Fyrol PNX) and expandable graphite (EG) were prepared, inspected and compared to foam without that fillers as the control. The thermal stability of PUFs was described by horizontal test according to norm: UL 94 HB. Compressive strength and physical properties (density, fragility and water absorption)...
-
MnCo2O4 deposited by spray pyrolysis as a protective layer for stainless steel interconects
PublikacjaStainless steel interconnects working in Solid Oxide Fuel Cells stacks are exposed to high temperature resulting in their corrosion. Protective layers for the hydrogen and oxygen sides are necessary to protect the interconnect material, prolongate the stack lifetime and maintain the output power. In this paper MnCo2O4 protective layer for the oxygen side of the interconnect is deposited by spray pyrolysis and is examined.
-
A magnetic imprinted polymer nano-adsorbent with embedded quantum dots and mesoporous carbon for the microextraction of triazine herbicides
PublikacjaA magnetic molecularly imprinted polymer (MMIP) adsorbent incorporating amino-functionalized magnetite nanoparticles, nitrogen-doped graphene quantum dots and mesoporous carbon (MIP@MPC@NGQDs@ Fe3O4–NH2) was fabricated to extract triazine herbicides from fruit juice. The embedded magnetite nanoparticles simplified the isolation of the adsorbent from the sample solution. The N-GQDs and MPC enhanced adsorption by affinity binding...
-
Global Complex Roots and Poles Finding Algorithm in C × R Domain
PublikacjaAn algorithm to find the roots and poles of a complex function depending on two arguments (one complex and one real) is proposed. Such problems are common in many fields of science for instance in electromagnetism, acoustics, stability analyses, spectroscopy, optics, and elementary particle physics. The proposed technique belongs to the class of global algorithms, gives a full picture of solutions in a fixed region ⊂ C × R and...
-
Heterostructure based on exfoliated graphitic carbon nitride coated by porous carbon for photocatalytic H2 evolution
Publikacja -
Promotion of MXene (Ti3C2Tx) as a robust electrocatalyst for oxygen evolution reaction via active sites of ZIF-67 - In situ mechanism investigations
Publikacja -
Mesoporous carbon/graphitic carbon nitride spheres for photocatalytic H2 evolution under solar light irradiation
Publikacja -
Characterization of novel GdBa0.5Sr0.5Co2−xFexO5+δ perovskites for application in IT-SOFC cells
Publikacja -
High Cu content LaNi1-xCuxO3-δ perovskites as candidate air electrode materials for Reversible Solid Oxide Cells
Publikacja -
Effect of ionic size of dopants on the lattice structure, electrical and electrochemical properties of La2−xMxNiO4+δ (M = Ba, Sr) cathode materials
Publikacja -
Formation of ultra-small Mn3O4 nanoparticles trapped in nanochannels of hollow carbon spheres by nanoconfinement with excellent supercapacitor performance
Publikacja -
Status report on high temperature fuel cells in Poland – Recent advances and achievements
PublikacjaThe paper presents recent advances in Poland in the field of high temperature fuel cells. The achievements in the materials development, manufacturing of advanced cells, new fabrication techniques, modified electrodes and electrolytes and applications are presented. The work of the Polish teams active in the field of solid oxide fuel cells (SOFC) and molten carbonate fuel cell (MCFC) is presented and discussed. The review is oriented...
-
CFD modeling of a diesel evaporator used in fuel cell systems
Publikacja -
How to determine whether an electron transfer channel is type-II or S-scheme in g–C3N4–based photocatalysts? A critical review
Publikacja -
Electrolytic deposition of reactive element thin films on Crofer 22 APU and evaluation of the resulting high-temperature corrosion protection properties at 700 °C–900 °C
PublikacjaThis article presents electrolytic deposition of thin Rare Earth (RE) coatings on Crofer 22 APU stainless steel substrates for high temperature applications, such as interconnects in solid oxide cell stacks. The deposition of coatings based on yttrium-, gadolinium-, lanthanum-, and cerium nitrates is discussed. The high temperature corrosion properties of surface-modified steels were examined using thermogravimetry and electrical...
-
Cu supported on various oxides as a candidate catalyst for dry methane reforming in DIR-SOFCs systems
PublikacjaA series of Cu-support systems were tested as potential candidates for DIR-SOFC (Direct Internal Reforming SOFC) catalysts towards a dry reforming of methane (DRM). The various supports (-Al2O3, CeO2, ZrO2, SrTiO3) with comparable specific surface area (SSA), and additionally -Al2O3 with SSA an order of magnitude larger than that of the other supports has been applied. The obtained Cu-support systems were characterized in terms...
-
Structural and electrical properties of Cr-doped SrTiO 3 porous materials
PublikacjaSeries of single-phase materials with assumed formula SrTi1−xCrxO3 (where x = 0, 1, 4, 6 mol.%) were obtained by sol-gel method. The structure and microstructure of materials were characterised by X-ray diffraction and scanning electron microscopy methods. Moreover, the study of electrical properties and evaluation of chemical stability in CO2/H2O atmosphere was performed by electrochemical impedance spectroscopy and thermogravimery...
-
High-performance NdSrCo2O5+δ–Ce0.8Gd0.2O2-δ composite cathodes for electrolyte-supported microtubular solid oxide fuel cells
PublikacjaNdSrCo2O5+δ (NSCO) is a perovskite with an electrical conductivity of 1551.3 S cm−1 at 500 °C and 921.7 S cm−1 at 800 °C and has a metal-like temperature dependence. This perovskite is used as the cathode material for Ce0.8Gd0.2O2-δ (GDC)-supported microtubular solid oxide fuel cells (MT-SOFCs). The MT-SOFCs fabricated in this study consist of a bilayer anode, comprising a NiO–GDC composite layer and a NiO layer, and a NSCO–GDC...
-
The effect of Fe on chemical stability and oxygen evolution performance of high surface area SrTix-1FexO3-δ mixed ionic-electronic conductors in alkaline media
PublikacjaDevelopment of environmentally friendly, high performing oxygen evolution reaction (OER) catalysts is an important research challenge. In this work, iron doped strontium titanates with a general formula SrTi1-xFexO3-δ (x = 0.35, 0.50, 0.70, 0.90, and 1.00) denoted as STFx, were synthesized via a solid state reaction technique and characterized in terms of oxygen evolution reaction electrocatalysis in an alkaline electrolyte (0.1...
-
Effect of small quantities of potassium promoter and steam on the catalytic properties of nickel catalysts in dry/combined methane reforming
PublikacjaCarbon dioxide and methane are two of the principal greenhouse gases. Reduction of their content in the atmosphere is currently the subject of much worldwide research. Dry and combined reforming of methane are effective methods of CO2 and CH4 utilization and production of synthesis gas (syngas) in chemical technology. Testing of catalysts that provide the desired H2/CO ratio and long operation time is one of the critical aspects...
-
Influence of Gd deposition on the oxidation behavior and electrical properties of a layered system consisting of Crofer 22 APU and MnCo2O4 spinel
PublikacjaIn the study, the surface of the Crofer 22APU ferritic steel was modified with gadolinium oxide nanoparticles and a protective-conducting layer consisting of the MnCo2O4 spinel. This system was studied in the context of application in IT-SOFC interconnects. Four types of samples were studied: unmodified steel, steel coated with a manganese-cobalt spinel layer, steel modified with gadolinium oxide nanoparticles, and a system consisting...
-
In situ study of a composition of outlet gases from biogas fuelled Solid Oxide Fuel Cell performed by the Fourier Transform Infrared Spectroscopy
PublikacjaThe purpose of this study was to develop a method and software based on the Fourier Transform Infrared Spectroscopy for the in-situ, quantitative analysis of the composition of outlet gases from Solid Oxide Fuel Cell (SOFC). The calibration procedure performed at the beginning of the experiment indicated a polynomial dependence between the concentration of a calibrating gas (CO, CO2, CH4) and the corresponding integrated absorbance in...
-
Characteristics of La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ -supported micro-tubular solid oxide fuel cells with LaCo 0.4 Ni 0.6-x Cu x O 3-δ cathodes
PublikacjaIn this study, micro-tubular solid oxide fuel cells (T-SOFCs) with extruded La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM) electrolyte as the mechanical support and LaCo0.4Ni0.6O3-δ (LCNO) or LaCo0.4Ni0.4Cu0.2O3-δ (LCNCO) as cathodes were prepared and characterized. Partial substitution of Cu for the Ni-ion positions in the LCNO lattices was found to significantly enhance the densification and accelerate the grain growth. The porosity-corrected...
-
MnxCo3-xO4 spinel oxides as efficient oxygen evolution reaction catalysts in alkaline media
PublikacjaThe design of efficient electrocatalysts for oxygen evolution reaction (OER) is an essential task in developing sustainable water splitting technology for the production of hydrogen. In this work, manganese cobalt spinel oxides with a general formula of MnxCo3-xO4 (x=0, 0.5, 1, 1.5, 2) were synthesised via a soft chemistry method. Non-equilibrium mixed powder compositions were produced, resulting in high electrocatalytic activity....
-
Laser induced formation of copper species over TiO2 nanotubes towards enhanced water splitting performance
PublikacjaWe proposed fast and scalable route where the ordered TiO2 nanotubes coated with thin copper layers were annealed by the laser beam of 355 nm wavelength at different fluencies in the range of 15–120 mJ/cm2. As a result, copper species are integrated with the titania substrate and the formed material exhibits unique optical absorption bands in the visible range. Moreover, X-ray photoelectron spectroscopy analysis reveals the formation...
-
Structural and catalytic properties of ceria layers doped with transition metals for SOFCs fueled by biogas
PublikacjaThe aim of this paper was to investigate an influence of the nanocrystalline Ce0.8A0.2O2-δ (A = Mn, Fe, Co, Ni, Cu) materials on the direct internal reforming of biogas in SOFC. Structural analysis of fabricated compounds has been done. An in-situ analysis of a composition of outlet gases from operating SOFC was performed using FTIR spectroscopy with simultaneous electrical tests. It was found out, that type of dopant strongly...
-
Exsolution of Ni nanoparticles on the surface of cerium and nickel co-doped lanthanum strontium titanate as a new anodic layer for DIR-SOFC. Anti-coking potential and H2S poisoning resistance of the prepared material
PublikacjaThe aim of this study was to evaluate a new catalytic material for biogas fueled DIR-SOFC. This material was a perovskite-type SrTiO3 doped with La, Ce and Ni of a general formula La0.27Sr0.54Ce0.09Ni0.1Ti0.9O3-σ (LSCNT). Additional preparation steps were undertaken to promote a nickel exsolution process. Heat post-treatment of powders in a humidified H2 resulted in an intensive growth of nickel nanoparticles (NPs) while the temperature...
-
Investigation of praseodymium and samarium co-doped ceria as an anode catalyst for DIR-SOFC fueled by biogas
PublikacjaThe Pr and Sm co-doped ceria (with up to 20 mol.% of dopants) compounds were examined as catalytic layers on the surface of SOFC anode directly fed by biogas to increase a lifetime and the efficiency of commercially available DIR-SOFC without the usage of an external reformer. The XRD, SEM and EDX methods were used to investigate the structural properties and the composition of fabricated materials. Furthermore, the electrical...
-
Electrochemical properties of porous Sr0.86Ti0.65Fe0.35O3 oxygen electrodes in solid oxide cells: Impedance study of symmetrical electrodes
PublikacjaThis work evaluates porous Sr0.86Ti0.65Fe0.35O3 (STF35) as a possible oxygen electrode material for Solid Oxide Cells. The powder synthesis was performed by solid state method. Characterization included DC electrical conductivity study of sintered bulk samples and impedance spectroscopy study of symmetrical electrodes deposited on gadolinium doped ceria substrates. Measurements were carried out in atmospheres with different pO2...
-
Suspension and process parameters selection for electrophoretic deposition of Mn–Co spinel coating on steel interconnects
PublikacjaMetallic interconnect coatings, consisting of MnCo2O4 spinel, were effectively applied to Crofer 22 APU using the electrophoretic deposition (EPD) method in both H2O: ethanol and pure ethanol solvents. The primary goal of this method was to prevent chromium migration, minimize evaporation, and control the oxidation rate. The study aimed to assess the quality, adhesion, and thickness of the Mn–Co coating, with the objective of...
-
Effects of Ni-NCAL and Ni–Ag electrodes on the cell performances of low-temperature solid oxide fuel cells with Sm0.2Ce0·8O2-δ electrolyte at various temperatures
PublikacjaThree low-temperature solid oxide fuel cells are built using Sm0.2Ce0·8O2-δ (SDC) as the electrolyte. Cell A is symmetrical and features Ni–LiNi0.8Co0·15Al0·05O2 (Ni–NCAL) electrodes, Cell B comprises a Ni–NCAL anode and a Ni–Ag cathode, and Cell C is fabricated using a Ni–NCAL cathode and a Ni–Ag anode. The ohmic resistance and polarization resistance (Rp) of Cells B and C are significantly higher than those of Cell A. The reduction...
-
High-temperature Co-electrolysis of CO2/H2O and direct methanation over Co-impregnated SOEC. Bimetallic synergy between Co and Ni
PublikacjaTo study the synergy between the transition metals for enhancing the electrochemical and chemical activity, a series of SOECs were modified with a small amount of Co ions, namely 1.8, 3.6, and 5.4 wt% in the reduced state. The addition of βCD into the precursor solution allowed for extremely fine dispersion of Co species across the Ni-YSZ cermet structure. The sample containing 3.6 wt% Co reached an outstanding over 2.5-times-higher...
-
Nickel phase deposition on V2CTx/V2AlC as catalyst precursors for a dry methane reforming: The effect of the deposition method on the morphology and catalytic activity
PublikacjaDry reforming of methane (DRM) is a promising alternative technology for the production of syngas with simultaneous utilization of two main greenhouse gases (CH4, CO2). However, DRM technology is still an industrially immature process due to the lack of stable and active catalyst. Therefore, the search for new catalytic materials is of great research interest. Recently, MAX and MXenes materials are increasingly being tested as...