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Search results for: metal-insulator transition
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Insulator to correlated metal transition in V1−xMoxO2
PublicationDyskutowane jest przejście typu izolatro - metal w domieszkowanym atomami Molibdenu związku V1-xMoxO2. Prezentowany jest diagram fazowy.
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Insulator to correlated metal transition inV1−xMoxO2
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Calixthioamides as ionophores for transition and heavy-metal cations
PublicationThere is an increasing interest in applying p-tert-butylcalix[4]arenes as sensing materials in ion-selective electrodes(ISEs). Considerable efforts were made to design calixarenes that are selective for some heavy- or transitionmetal ions to be used in ISEs for controlling and monitoring the level of such pollutants in the environment. It has been reported that introduction of softer sulfur atoms instead of oxygen atoms in calix[4]arene...
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Nanostructure of the laser-modified transition metal nanocomposites for water splitting
PublicationAlthough hydrogen is considered by many to be the green fuel of the future, nowadays it is primarily produced through steam reforming, which is a process far from ecological. Therefore, emphasis is being put on the development of electrodes capable of the efficient production of hydrogen and oxygen from water. To make the green alternative possible, the solution should be cost-efficient and well processable, generating less waste...
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Transition Metal Oxides influence on phosphate and borate glasses structure
PublicationBorate and phosphate glasses possess many potential luminescence and optical applications. With their low melting point, they are one of the most often studied amorphous materials. In recent years these glasses, doped with transition metal oxides (TMO), gained much attention due to their tunable structural and thermal properties. Review of systems containing TMOs was presented. Additionally synthesis of binary MnO-P2O5 and MnO-B2O3...
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Syntheses and Structures of Transition Metal Complexes with Phosphanylphosphinidene Chalcogenide Ligands
PublicationThe reactivity of the phosphanylphosphinidene complex [(DippN)2W(Cl)(η2-P-PtBu2)]− (1) toward chalcogens (Ch = Se, S) was studied. Reactions of stoichiometric amounts of 1 with chalcogens in DME yielded monomeric tungsten complexes with phosphanylphosphinidene chalcogenide ligands of the formula tBu2P−P−Ch (Ch = Se (in 2) and S (in 5)), which can be regarded as products of the addition of a chalcogen atom to a P=W bond in starting...
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Calix[4]arene-Thioamides as Ionophores for Transition and Heavy Metal cations
PublicationCalix[4]arene derivatives play an important role as sensing materials in Ion Selective Electrodes(ISEs). Nowadays a high impact is put to control in natural waters the level of toxic heavy metals, like Pb ,Cd, Hg or Cu which may cause the great risk to human health. Our goal was to design and to synthesize ligands possessing ability to bind transition and heavy metal cations. The synthesis, crystal structures,extractive and ionophoric...
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Application of Coordination Compounds with Transition Metal Ions in the Chemical Industry—A Review
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Calix[4]arene-Thioamides as Ionophores for Transition and Heavy Metal Cations.
PublicationPochodne kaliks[4]arenów odgrywają ważną rolę jako materiał aktywny w membranowych elektrodach jonoselektywnych. Obecnie duży nacisk kładzie się na kontrolę stężeń kationów metali ciężkich, takich jak Pb, Cd, Hg, Cu w wodach naturalnych. Naszym zadaniem było zaprojektować i zsyntezować ligandy, które wykazują zdolność do wiązania kationów metali ciężkich i przejściowych. Synteza, struktury krystaliczne, ekstrakcja i właściwości...
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Identification of multisite behavior in a broadly emitting transition-metal system using pressure
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Transition-Metal-Promoted Oxidative Cyclization To Give 1,2,4-Trisubstituted Carbazole Scaffolds
PublicationHerein, we describe the synthesis of a 1,2,4-trisubstituted carbazole core from 5-(1H-indol-3-yl)-3-oxopentanoic acid esters or amides. For oxidative cyclization, we tested two different approaches. First, we used manganese triacetate as a conventional moderate oxidizer to ensure the radical course of the reaction. Second, we examined the use of a more complex oxidizing agent I2/Me(OTf)3. In both cases, formation of a fused-ring...
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Apparent molar volumes of divalent transition metal bromides in dimethyl sulfoxide solutions
PublicationWyznaczono pozorne i cząstkowe molowe objętości bromków dwuwartościowych metali przejściowych szeregu Mn(II)-Zn(II)w roztworach w dimetylosulfotlenku. Przedyskutowano korelacje między objętościami molowymi a stanami koordynacyjnymi i sposobem jonizacji soli.
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Functionalization of the transition metal oxides FeO, CoO, and NiO with alkali metal atoms decreases their ionization potentials by 3–5 eV
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Adiabatic Compressibilities of Divalent Transition-Metal Perchlorates and Chlorides in N,N-Dimethylacetamide and Dimethylsulfoxide
PublicationZmierzono prędkości rozchodzenia się dźwięku roztworów nadchloranów i chlorków manganu(II), kobaltu(II), niklu(II), miedzi(II) i cynku(II) w N,N-dimetyloacetamidzie i dimetylosulfotlenku w temperaturze 298.15 K. Obliczono ściśliwości adiabatyczne i pozorne ściśliwości adiabatyczne badanych roztworów. Przedyskutowano wpływ anionu i rodzaju rozpuszczalnika na uzyskane graniczne wartości pozornych ściśliwości adiabatycznych soli.
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Apparent molar volumes of divalent transition metal chlorides and perchlorates in dimethyl sulfoxide solutions.
PublicationZmierzono gęstości roztworów nadchloranów i chlorków dwuwartościowych metali szeregu Mn(II)-Zn(II) w dimetylosulfotenku. Wyznaczone na drodze ekstrapolacji cząstkowe objętości molowe nadchloranów rozdzielono na udziały jonowe. Przeanalizowano wpływ pola ligandów na cząstkowe objętości molowe kationów. Przedstawiono związek między wartościami pozornych objętości molowych a stanami koordynacyjnymi soli w DMSO.
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Apparent molar volumes of divalent transition metal perchlorates and chlorides in N,N-dimethylacetamide.
PublicationZmierzono gęstości roztworów nadchloranów i chlorków manganu(II), kobaltu(II), niklu(II), miedzi(II) i cynku(II) w temperaturach 10, 20,25, 30, 40, 50 i 60(o)C. Obliczono pozorne objętości molowe. Wyznaczono graniczne wartości cząstkowych molowych objętości tych soli oraz odpowiednie rozszerzalności. Przeanalizowano i wyjaśniono różnice we właściwościach wolumetrycznych roztworów nadchloranów i chlorków.
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Overview of the Synthesis and Catalytic Reactivity of Transition Metal Complexes Based on C═P Bond Systems
PublicationThis report provides an overview of the use of phosphaalkenes (C=P) in syntheses of various complexes. Going through successive complexes containing the d-block metals, we sought how this area of chemistry was formed over the years. Additionally, this work contains information on the possible coordination types and means of constructing the complexes. In addition, this review reveals the reactivities of phosphaalkene complexes...
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Mixed electronic-ionic conductivity in transition metal oxide glasses con-taining alkaline ions
PublicationOpisano właściwości elektryczne szkieł z tlenkami metali przejściowych zawierających jony metali alkalicznych. Szczególną uwagę zwrócono na typowe zmiany przewodnictwa występujące przy domieszkowaniu tego typu szkieł jonami metali alkalicznych. Porównano przewodnictwo elektryczne szkieł fosforanowo-żelazowych zawierających jony sodu z przewodnictwem szkieł bizmutowo-miedziowych.
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Solvation and partial molar volumes of some transition metal cations in N,N-dimethylacetamide, triethylphosphate and acetonitrile.
PublicationW oparciu o precyzyjne pomiary gęstości roztworów nadchloranów metali przejściowych szeregu Mn(II)-Zn(II) w DMA, TEP i AN wyznaczono pozorne molowe oraz graniczne wartości cząstkowych molowych objętości sole w temperaturach 293, 298 i 303,15 K. Wyznaczone wartości rozdzielono na udziały jonowe. Przeanalizowano czynniki decydujące o wielkości cząstkowych molowych objętości solwatowanych kationów.
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TRANSITION METAL CHEMISTRY
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O-substituted tetrahydroxamate derivatives of p-tert-butylcalix[4]arene as receptors for transition and heavy metal cations
PublicationTetrasubstituted O-hydroxamate derivatives of p-tert-butylcalix[4]arene were applied as active materials in ion-selective membrane electrodes and were tested towards Pb-selectivity. The electrodes gave near-Nernstian characteristics for Pb2+ cations. The selectivity coefficients were determined. The influence of plasticizer on the electrode behaviour was studied. The dependence of the chemical structure on selectivity coefficients...
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Anomalous anisotropy of deuterium-grown boron-doped diamond and the role of boron-tetramers in the Mott-Insulator transition
Open Research DataWe show anisotropy in the superconductivity for boron-doped diamond thin films prepared with Microwave Plasma Assisted Chemical Vapor Deposition using deuterium-rich plasma. This anomalous phase transition is linked with the emergence of boson quantum entanglement states behaving as a bosonic insulating state. Here, we show that the superconducting...
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Preparation of methanation catalysts for high temperature SOEC by β-cyclodextrin-assisted impregnation of nano-CeO2 with transition metal oxides
PublicationThe aim of this work was to prepare and examine the catalytic activity of nanometric CeO2 decorated with transition metal oxides – Ni, Co, Cu, Fe and Mn – towards a high-temperature methanation process under SOEC CO2/H2O simulated co-electrolysis conditions. Samples were prepared using the wet impregnation method via the conventional process and with the addition of native cyclodextrin. The influence of β-cyclodextrin (βCD) onto...
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Study of ZrS3-based field-effect transistors toward the understanding of the mechanisms of light-enhanced gas sensing by transition metal trichalcogenides
PublicationExtending knowledge of the properties of low-dimensional van der Waals materials, including their reactivity to the ambiance, is important for developing innovative electronic and optoelectronic devices. Transition metal trichalcogenides with tunable optical band gaps and anisotropic conductivity are an emerging class among low- dimensional structures with the possibility of gate tunability and photoreactivity. These properties...
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Achiral and Chiral Transition Metal Complexes with Modularly Designed Tridentate PNP Pincer-Type Ligands Based on N-Heterocyclic Diamines
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Interaction of Ionomers and Polyelectrolytes with Divalent Transition Metal Cations (Cu2+ and VO2+): A Study by Electron Spin Resonance (ESR) Spectroscopy and Viscosimetry
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Thermodynamic properties of inorganic salts in nonaqueous solvents. II. Apparent molar volumes and compressibilities of divalent transition-metal perchlorates in acetonitrile
PublicationW oparciu w wyniki pomiarów gęstości wykonanych w temperaturze 15,20,25,30,35,40 i 50 stopni Celsjusza oraz pomiaru szybkości dżwięku w temperaturze 25 stopni Celsjusza, wyznaczono pozorne objętości molowe oraz ściśliwości adiabatyczne roztworów nadchloranów manganu(II), kobaltu(II), niklu(II) i cynku(II). Obliczono odpowiednie wartości standardowe oraz rozszerzalności izobaryczne. Przeanalizowano związki między strukurą elektronową...
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Group-9 Transition-Metal Suboxides Adopting the Filled-Ti2Ni Structure: A Class of Superconductors Exhibiting Exceptionally High Upper Critical Fields
PublicationTi2Ni and the related η-carbide structure are known to exhibit various intriguing physical properties. The Ti2Ni structure with the cubic space group Fd3̅m is surprisingly complex, consisting of a unit cell with 96 metal atoms. The related η-carbide compounds correspond to a filled version of the Ti2Ni structure. Here, we report on the structure and superconductivity in the η-carbide-type suboxides Ti4M2O with M = Co, Rh, and Ir....
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Thermodynamic properties of inorganic salt in nonaqeous solvents. IV. Apparent molar volumes and compressibilities of divalent transition-metal bromides and chlorides in acetonitrile
PublicationWykonano pomiary gęstości roztworów chlorków i bromków w acetonitrylu w temperaturze 288.15, 293.15, 298.15, 303.15, 308.15, 313.15 K oraz pomiar szybkości rozchodzenia się dźwięku w badanych roztworach w temperaturze 298.15 K. Uzyskane wartości pozwoliły wyznaczyć pozorne objętości molowe oraz pozorne adiabatyczne ściśliwości, których wartości oraz zmiany ze stężeniem tłumaczone są obecnością złożonych układów komplesów w roztworze.
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Thermodynamic Properties of Inorganic Salts in Nonaqueous Solvents. VI. Apparent Molar Volumes, Expansibilities, and Compressibilities of Divalent Transition Metal Ions in Methanol and Dimethylsulfoxide
PublicationThe temperature dependence of the density of divalent transition metal perchlorates in dimethylsulfoxide as well as cobalt(II), nickel(II) perchlorates, and copper(II) trifluoromethanesulfonate in methanol was determined. Moreover, sound velocities for solutions of cobalt(II), nickel(II) perchlorates, and copper(II) trifluoromethanesulfonate in methanol have been measured at 298.15 K. From these data, the partial molar volumes,...
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Thermodynamic properties of inorganic salts in nonaqueous solvents. III. Apparent molar volumes and compressibilities of divalent transition-metal chlorides in N,N-dimethylformamide
PublicationZmierzono gęstości i szybkości dźwięku dla roztworów chlorków dwuwartościowych metali przejściowych w N,N-dimetyloformamidzie. W oparciu o uzyskane wyniki wyznaczono pozorne objętości molowe, cząstkowe objętości molowe, rozszerzalności izobaryczne oraz ściśliwości adiabatyczne. Dokonano analizy oraz zbadano wpływ kompleksowania na wyznaczone wielkości.
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Thermodynamic properties of inorganic salts in nonaqueous solvents. V. Apparent molar volumes and compressibilities of divalent transition metal bromides in N,N-dimethylformamide
PublicationZmierzono gęstości i szybkości rozchodzenia się dźwięku roztworów bromków dwuwartościowych metali przejściowych w N,N-dimetyloformamidzie. W oparciu o uzyskane parametry wyznaczono pozorne objętości i ściśliwości molowe. Dokonano analizy oraz zbadano wpływ kompleksowania na wyznaczone wielkości.
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Thermodynamic properties of inorganic salts in nonaqueous solvents. I. Apparent molar volumes and compressibilities of divalent transition-metal perchlorates in N,N-dimethylformamide.
PublicationZmierzono gęstości i szybkość dźwięku dla roztworów nadchloranów dwuwartościowych metali przejściowych w N,N-dimetyloformamidzie. W oparciu o uzyskane wyniki wyznaczono pozorne objętości molowe, cząstkowe objętości molowe, rozszerzalności izobaryczne oraz ściśliwości adiabatyczne. Dokonano analizy oraz zbadano wpływ rodzaju kationu metalu.
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Catalytic activity of Ni-MgAl2O4 modified with transition metal (Ti, Mo, W) carbides as potential catalysts for resource recovery via dry reforming of waste plastics
PublicationThe growing amounts of plastic waste and CO2 emissions are two environmental threats that require urgent attention. Pyrolysis combined with dry reforming (PCDR) is a technology that allows both CO2 utilization and resource recovery from waste plastic. New catalysts for PCDR are crucial for developing efficient and stable processes that can be widely implemented in the industry. In this study, Ni/MgAl2O4 catalysts modified using different...
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Synthesis, spectroscopy and crystal structure determination of heteroleptic cobalt(II) silanethiolates with pyridine derivatives
PublicationCztery nowe tri-tert-butoksysilanotiolanowe kompleksy kobaltu(II) z 3- i 4-metylopirydyną zostały zsyntetyzowane i scharakteryzowane. Monometaliczne kompleksy otrzymano w reakcji bimetalicznego kompleksu [Co(SSi(OtBu)3(NH3)]2, który posłużył jako substrat kobaltu(II). Nowe związki zostały scharakteryzowane przy użyciu rentgenografii strukturalnej oraz spektroskopii UV-vis i FT-IR, a także za pomocą analizy elementarnej. Kompleksy...
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Polaronic and Mott insulating phase of layered magnetic vanadium trihalide VCl3
PublicationTwo-dimensional (2D) van der Waals (vdW) magnetic 3d-transition metal trihalides are a new class of functional materials showing exotic physical properties useful for spintronic and memory storage applications. In this article, we report the synthesis and electromagnetic characterization of single-crystalline vanadium trichloride, VCl 3 , a novel 2D layered vdW Mott insulator, which has a rhombohedral structure (R3, No. 148) at...
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The luminescence study of (C10H16N)2MnBr4 Organic–Inorganic Hybrid
Open Research DataOrganic–inorganic hybrid metal halides have recently attracted attention in the global research field for their bright light emission, tunable photoluminescence wavelength, and convenient synthesis method. This study reports the detailed properties of (C10H16N)2MnBr4, which emits bright green light with a high photoluminescence quantum yield. Results...
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A first-principles study of electronic and magnetic properties of 4d transition metals doped in Wurtzite GaN for spintronics applications
PublicationWe studied the electronic and magnetic properties of wurtzite GaN (w-GaN) doped with different concentrations of the 4d transition metal ions Nb, Mo, and Ru. We incorporated spin-polarized plane-wave density functional theory within an ultrasoft pseudopotential formalism. The 4d transition metals were doped at different geometrical sites to determine the geometry with the lowest total energy and the one that induced the largest...
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Bonding in Phosphanylphosphinidene Complexes of Transition Metals and their Correlation with Structures, 31 P NMR Spectra, and Reactivities
PublicationTheoretical studies of the bonding interactions and most important properties are carried out for isolable phosphanylphosphinidene complexes of transition metals. Three main types of phosphanylphosphinidene complexes are distinguished, based on the way in which the phosphanylphosphinidene ligand bonds to the metal center: (i) side-on complexes of platinum, where the R2Pβ–Pα ligand mimics structural features of free singlet phosphanylphosphinidenes...
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Electrical responses of nanostructured ZrS3 as field-effect transistor for nitrogen dioxide, ethanol, and acetone detection enhanced by visible light
Open Research DataSmall-area layers of nanostructured ZrS3 were fabricated and measured in the field-effect transistor configuration. Irradiation with visible light enabled generating photocurrent and increasing the sensitivity to selected ambient gases: nitrogen dioxide, ethanol, and acetone. The data set consists of electrical responses (current vs. voltage characteristics...
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Possible quadrupole-order-driven commensurate-incommensurate phase transition in B20 CoGe
PublicationThe B20-type cobalt germanide CoGe was investigated by measuring the specific heat, resistivity, and 59Co nuclear magnetic resonance (NMR).We observed a phase transition at TQ = 13.7 K, evidenced by a very narrow peak of the specific heat and sharp changes of the nuclear spin-spin (T −1 2 ) and spin-lattice (T −1 1 ) relaxation rates. The fact that the entropy release is extremely small and the Knight shift is almost independent...
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Superconductivity in Metal-Rich Chalcogenide Ta2Se
PublicationThe metal–metal bond in metal-rich chalcogenide is known to exhibit various structures and interesting physical properties. Ta2Se can be obtained by both arc-melting and solid-state pellet methods. Ta2Se crystallizes a layered tetragonal structure with space group P4/nmm (No. 129; Pearson symbol tP6). Each unit cell consists of four layers of body-centered close-packing Ta atoms sandwiched between two square nets of Se atoms, forming...
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Agnieszka Pladzyk dr hab. inż.
PeopleAgnieszka Pladzyk, born in 1973 in Pisz, graduated in 1998 in Biotechnology from the Faculty of Chemistry GUT. Her MSc thesis entitled Production of recombinant human calcitonin in bacterial system and its purification with the use of metal affinity chromatography was done under the supervision of professor Józef Kur. In 2003 she defended the PhD with distinctions and her PhD thesis entitled Cobalt tri-tert-butoxysilanethiolates...
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S-Shaped Suppression of the Superconducting Transition Temperature in Cu-Intercalated NbSe2
Publication2H-NbSe2 is the prototype and most frequently studied of the well-known transition metal dichalcogenide (TMDC) superconductors. As 2H-NbSe2 is widely acknowledged as a conventional superconductor, its transition temperature to the superconducting state (Tc) is 7.3 K, a Tc that is substantially higher than those seen for the majority of TMDCs, where Tc values between 2 and 4 K are the norm. Here we report the intercalation of Cu...
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The effect of metal cluster deposition route on structure and photocatalytic activity of mono- and bimetallic nanoparticles supported on TiO2 by radiolytic method
PublicationTiO2 (P25) was modified with small and relatively monodisperse mono- and bimetallic clusters (Ag, Pd, Pt, Ag/Pd, Ag/Pt and Pd/Pt) induced by radiolysis to improve its photocatalytic activity. The as-prepared samples were characterized by X-ray fluorescence spectrometry (XRF), photoluminescence spectrometry (PL), diffuse reflectance spectroscopy (DRS), X-ray powder diffractometry (XRD), scanning transition electron microscopy (STEM)...
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Metal (Mo, W, Ti) Carbide Catalysts: Synthesis and Application as Alternative Catalysts for Dry Reforming of Hydrocarbons—A Review
PublicationDry reforming of hydrocarbons (DRH) is a pro-environmental method for syngas production. It owes its pro-environmental character to the use of carbon dioxide, which is one of the main greenhouse gases. Currently used nickel catalysts on oxide supports suffer from rapid deactivation due to sintering of active metal particles or the deposition of carbon deposits blocking the flow of gases through the reaction tube. In this view,...
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On the relationship between the structural and volumetric properties of solvated metal ions in O-donor solvents using new structural data in amide solvents
PublicationThe structures of the N,N-dimethylformamide (dmf), N,N-dimethylacetamide (dma), and N,N-dimethylpropionamide (dmp) solvated strontium and barium ions have been determined in solution using large angle X-ray scattering and EXAFS spectroscopy. The strontium ion has a mean coordination number (CN) between 6.2 and 6.8, and the barium ion has a mean CN between 7.1 and 7.8 in these amide solvents. The non-integer numbers indicates that...
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Ranking of Heterogeneous Catalysts Metals by Their Greenness
PublicationCatalysis is very important process in industry and laboratory practice, especially from the point of green chemistry principles. However, eco-friendly character of heterogeneous catalysts, containing transition metal components has not been evaluated, yet. Therefore, we perform a comprehensive assessment of 18 heterogeneous metal catalysts (Pd, Pt, V, Co, Ni, Mo, Ru, Mn, Au, Cu, Cd, Zr, Fe, Rh, Ir, Sn, Zn, Ag) using multicriteria...
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SEM/EDX data of (Cr,Fe,Mn,Co,Ni)3O4 High-entropy spinel oxide thin films deposited on amorphous SiO2 substrate by spray pyrolysis techniqe
Open Research DataThis Data set include SEM and EDX results of (Mn,Co,Fe,Ni,Cr)3O4 high-entropy spinel oxide prepared in the form of a ~ 500 nm thin film utilising a facile spray pyrolysis technique. The structural and electrical properties of the layers were characterised after exposure to temperatures in the range of 400–900 ◦C. The as-deposited layers were amorphous,...
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TEM data of (Cr,Fe,Mn,Co,Ni)3O4 High-entropy spinel oxide thin films deposited on amorphous SiO2 substrate by spray pyrolysis techniqe
Open Research DataThis Dataset include presentation of summarized TEM investigation of (Mn,Co,Fe,Ni,Cr)3O4 high-entropy spinel oxide prepared in the form of a ~ 500 nm thin film utilising a facile spray pyrolysis technique. The structural and electrical properties of the layers were characterised after exposure to temperatures in the range of 400–900 ◦C. The as-deposited...