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Search results for: X-RAY COMPUTED TOMOGRAPHY
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Preparation and characterization of Pt–N/TiO2 photocatalysts and their efficiency in degradation of recalcitrant chemicals
PublicationSeries of Pt–N/TiO2 photocatalysts were synthesized using the sol–gel method. The photocatalysts’ characteristics by X-ray diffractometry (XRD), scanning transmission electron microscopy (STEM), diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) showed that sample with the molar ratio Ti:N equal 1:4 and platinum nanoparticles size of about 3 nm had anatase structure, about 94 m2/g specific surface area...
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Enhanced photocatalytic properties of lanthanide-TiO2 nanotubes: An experimental and theoretical study
PublicationA series of Er-, Yb-, Ho-, Tb-, Gd-, Pr-TiO2 nanotubes (RE-NTs) was prepared via an electrochemical method. The as-prepared photocatalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis absorption, scanning electron microscopy (SEM) and luminescent spectroscopy. The experiments demonstrated that toluene in the gas phase was successfully degraded under visible light (LEDs λmax = 465...
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Ferromagnetic nanocrystallites in the SiO2 - PbO - Fe2O3 glass system
PublicationThe structure of 50% SiO2 - 35% PbO - 15% Fe2O3, 50% SiO2 - 30% PbO - 20% Fe2O3 and 50% SiO2 - 25% PbO - 25% Fe2O3 (in mol%) glass was investigated by the means of AFM microscopy and X-ray diffraction. Observation by the atomic force microscopy shows that each of prepared iron oxide glass doesn't have homogeneous structure and some nanocrystallites were detected. Next, test with neodymium magnet found out strong magnetic properties...
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Experimental tuning of AuAg nanoalloy plasmon resonances assisted by machine learning method
PublicationPlasmonic nanostructures based on AuAg nanoalloys were fabricated by thermal annealing of metallic films in an argon atmosphere. The nanoalloys were chosen because they can extend the wavelength range in which plasmon resonance occurs and thus allow the design of plasmonic platforms with the desired parameters. The influence of initial fabrication parameters and experimental conditions on the formation of nanostructures was investigated....
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Możliwości wykorzystania spektroskopii fotoelektronów w analizie jakości środowiska wodnego
PublicationSpektroskopia fotoelektronów w zakresie promieniowania X, (XPS, z ang. X-ray photoelectron spectroscopy) jest nowoczesną metodą analityczną wykorzystywaną w wielu wiodących ośrodkach naukowych na świecie. Jest ona stale ulepszana, jak też poznawane są nowe obszary jej zastosowania. W niniejszym artykule przedstawione zostały możliwości wykorzystania metody XPS w ramach obszarów badawczych powiązanych z gospodarką wodną, takich...
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Lower rim substituted p-tert-butylcalix[4]arene; Part 14. Synthesis, structures and binding studies of calix[4]arene thioamides
PublicationA number of p-tert-butylcalix[4]arene thioamides were synthesized and characterized by 1H-NMR and elemental analysis. Compounds 1-5 are O-substituted derivatives with -CH2-C(=S)-N-X groups, where NX = morpholidyl, NEt2, NHC2H4Ph, NHCH2Ph and NHEt,respectively. The X-ray structures of the ligands 1, 3, 5 and of the complex 3Pb(ClO4)2, (compound 6), are presented and their slightly distorted cone conformation is established. The...
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Spin-glass behavior in a binary Pr 3 Ir intermetallic compound
PublicationPolycrystalline Pr3Ir was synthesized by arc melting. Its cementite-type crystal structure (Pnma) was confirmed by powder X-ray diffraction and estimated lattice parameters are in agreement with literature. Physical properties were measured by means of the ac and dc magnetic susceptibility, electrical resistivity and heat capacity. Our results indicate spin-glass behavior in Pr3Ir with a freezing temperature Tf = 6.58 K and activation...
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Characterization of Small Azocrown Ether Stereoisomers.
PublicationWyizolowano i zbadano metodą X-ray, 1H NMR i UV-Vis trwałe izomery E i Z 10-członowej azokorony. Ich struktura w stanie stałym świadczy o naprężonej konformacji w przypadku izomeru trans i nie naprężonej dla izomeru cis. Jest to efektem sprzężenia p grupy azowej z benzenem i naprężenia sterycznego konformacji cząsteczki.
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Photoactivity of decahedral TiO2 loaded with bimetallic nanoparticles: Degradation pathway of phenol-1- 13 C and hydroxyl radical formation
PublicationDecahedral TiO2decorated with bimetallic nanoparticles were synthesized via radiolysis and photode-position method. The effect of bimetallic surface composition (Ag Pt, Ag Au, Au Pd, Au Pt) as well asdeposition technique (simultaneous or sequential) on the photocatalytic activity in phenol degradationand efficiency of hydroxyl radicals generation under UV–vis light irradiation were investigated. Modifiedand pristine decahedral...
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Structure and magnetic properties of BeO-Fe2O3-Al2O3-TeO2 glass-ceramic composites
PublicationIn this work, glass-ceramics in the xBeO–20Fe2O3–(80-x)TeO2 system with x = 0–25 mol% were synthesized by the traditional melt quenching route and studied by inductively coupled plasma optical emission spectroscopy, X-ray diffraction, confocal microscopy, infrared and Raman spectroscopy. BeO addition was found to support the crystallization process of Fe2O3 during melting, and an increased BeO content was associated with an increased...
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Photoresponsive, amide-based derivative of embonic acid for anion recognition
PublicationThe synthesis and ion-binding properties of amide-based derivative of embonic acid andp-aminoazobenzenewere described. The new compound was characterized by X-ray structural analysis and spectroscopic methods.Ligand interacts in acetonitrile with Y-shaped anions (benzoates and acetates) and dihydrogen phosphatesforming complexes of 1:1 stoichiometry. In more polar DMSO the complexes stoichiometry changes to 2:1(L:anion). Light-inducedtranstocisisomerization...
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KOLMOGOROV EQUATION SOLUTION: MULTIPLE SCATTERING EXPANSION AND PHOTON STATISTICS EVOLUTION MODELING
PublicationWe consider a formulation of the Cauchy problem for the Kolmogorov equation which corresponds to a localized source of particles to be scattered by a medium with a given scattering amplitude density. The multiple scattering amplitudes are introduced and the corresponding series solution of the equation is constructed. We investigate the integral representation for the first series terms, its estimations and values of the photon...
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Emerging oxidized and defective phases in low-dimensional CrCl3
PublicationTwo-dimensional (2D) magnets such as chromium trihalides CrX3 (X ¼ I, Br, Cl) represent a frontier for spintronics applications and, in particular, CrCl3 has attracted research interest due its relative stability under ambient conditions without rapid degradation, as opposed to CrI3. Herein, mechanically exfoliated CrCl3 flakes are characterized at the atomic scale and the electronic structures of pristine, oxidized, and defective...
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Studies on novel BiyXz-TiO2/SrTiO3 composites: Surface properties and visible light-driven photoactivity
PublicationA series of novel BiyXz-TiO2/SrTiO3 composites were prepared by multistep synthesis route. The asprepared photocatalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), Fourier transform infrared (FT-IR), Raman spectra and BET analysis. The photocatalytic activity test was performed in aqueous solution of phenol under...
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Ultrasound-assisted wet-impregnation of Ag–Co nanoparticles on cellulose nanofibers: Enhanced catalytic hydrogenation of 4-nitrophenol
PublicationIn this study, a novel nanocomposite of bimetallic Ag–Co nanoparticles supported on cellulose nanofibers (CNFs) was synthesised using the ultrasound-assisted wet-impregnation method for catalytic applications. CNFs were prepared from cellulose acetate using the electrospinning technique. Fourier transform infrared spectroscopy (FTIR) analysis confirmed the successful synthesis of CNFs. Further, scanning electron microscopy (SEM)...
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From Structure to Luminescent Properties of B2O3-Bi2O3-SrF2 Glass and Glass-Ceramics Doped with Eu3+ Ions
PublicationGlass-ceramics with the composition B2O3 -Bi2O3 -SrF2 were synthesized by the conventional melt-quenching technique and subsequent crystallization of the parental glasses. The temperature at which the ceramization was carried out was selected based on differential scanning calorimetry (DSC) analysis. The structure of the studied materials and the formation of SrF2 nanocrystals were confirmed by the Fourier-transform infrared spectroscopy...
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Photocatalytic and Antimicrobial Properties of Ag2O/TiO2 Heterojunction
PublicationAg2O/TiO2 heterojunctions were prepared by a simple method, i.e., the grinding of argentous oxide with six different titania photocatalysts. The physicochemical properties of the obtained photocatalysts were characterized by diffuse-reflectance spectroscopy (DRS), X-ray powder diffraction (XRD) and scanning transmission electron microscopy (STEM) with an energy dispersive X-ray spectroscopy (EDS). The photocatalytic activity was...
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Hydrothermal reactions: From the synthesis of ligand to new lanthanide 3D-coordination polymers
PublicationThe organic ligand 2,5-piperazinedione-1,4-diaceticacid (H2PDA) was synthesized under hydrothermal conditions starting from the iminodiacetic acid and catalyzed by oxalic acid. The X-ray powder diffraction data indicates that the compound crystallizes in the P21/c space group as reported in the literature. The ligand was also characterized by elemental analysis, magnetic nuclear resonance, infrared spectroscopy and thermogravimetric...
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Pressure effects on the superconductivity of the HfPd2Al Heusler compound: Experimental and theoretical study
PublicationPolycrystalline HfPd2Al has been synthesized using the arc-melting method and studied under ambient-pressure conditions by x-ray diffraction from room temperature up to 450 °C. High-pressure x-ray diffraction up to 23 GPa was also performed using Diacell-type membrane diamond anvil cells. The estimated linear thermal expansion coefficient was found to be α=1.40(3)×10−5K−1, and the bulk modulus derived from the fit to the third-order...
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Visible light activity of rare earth metal doped (Er3+, Yb3+ or Er3+/Yb3+) titania photocatalysts
PublicationA series of Er3+-TiO2, Yb3+-TiO2 and Er3+/Yb3+-TiO2 photocatalysts were obtained via sol-gel method, using rare earth metal (RE) precursor ranging from 0.25 to 10 mol%. The experiments demonstrated that phenol in aqueous solutions was successfully degraded under visible light (> 450 nm) using RE3+-TiO2. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron emission spectroscopy (XPS), UV-Vis...
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Synthesis, spectroscopy and computational studies of some biologically important hydroxyhaloquinolines and their novel derivatives
PublicationA series crystalline compounds of methyl and phosphinyl derivatives of 2-methylquinolin-8-ol (1a) and related 5,7-dichloro-2-methylquinolin-8-ol (1b) were quantitatively prepared and characterized by microanalysis, IR, UV-vis and multinuclear NMR spectroscopy. Five of them have been characterized by single crystal X-ray diffraction method. The known compounds, 8-methoxy-2-methylquinoline (2a) and 8-methoxyquinoline (2d), were synthesised...
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Optimization of boron-doping process of titania nanotubes via electrochemical method toward enhanced photoactivity
PublicationIn this work, we were focused on the development of the electrochemical approach resulting in a stable boron doping of titania nanotubes. The doping procedure concerns anodic polarization of as-anodized titania in a H3BO3 solution acting as n boron precursor. The series of attempts were taken in order to elaborate the most beneficial doping conditions. The parameters of electrochemical doping allowing to obtain boron-doped titania...
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Nanoporous TiO2 electrode grown by laser ablation of titanium in air at atmospheric pressure and room temperature
PublicationRecently, fabrication of the nanoporous TiO2 photoelectrode on metal foils by means of sputtering of the Ti film on preheatedmetal substrate followed by the TiO2 deposition (doctor blade technique) and sintering represents the frequently applied technique. This is despite the relatively complicated procedure and number of parameters to be controlled in order to fabricate films of required properties. In this work an approach is...
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Novel, Fully Biobased Semicrystalline Polyamides
PublicationNovel, semicrystalline polyamides and co(polyamides) were synthesized from biobased sebacic acid (SA), 2,5-diamino-2,5-dideoxy-1,4;3,6-dianhydroiditol (diaminoisoidide, DAII) as well as from 1,4-diaminobutane (DAB), also known as putrescine in nature. Low molecular weight polyamides were obtained by melt polycondensation of the salts based on these monomers or by interfacial polycondensation. In order to increase their molecular...
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The effect of PEDOT morphology on hexavalent chromium reduction over 2D TiO2/PEDOT photocatalyst under UV–vis light
PublicationThe present study represents an approach to apply organic-inorganic hybrid materials for photocatalytic removal of heavy metals from the aqueous environment. The photocatalytic activity of the semiconductor modified with the conjugated polymer may depends on the conjugated polymer type, its amount and morphology. Therefore, in the present study the effect of poly (3, 4-ethylenedioxythiophene) (PEDOT) morphology on adsorption and photoreduction...
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Rubrene Thin Films with Viably Enhanced Charge Transport Fabricated by Cryo-Matrix-Assisted Laser Evaporation
PublicationAmong organic semiconductors, rubrene (RB; C42H28) is of rapidly growing interest for the development of organic and hybrid electronics due to exceptionally long spin diffusion length and carrier mobility up to 20 cm2V−1s−1 in single crystals. However, the fabrication of RB thin films resembling properties of the bulk remains challenging, mainly because of the RB molecule’s twisted conformation. This hinders the formation of orthorhombic...
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Influence of Annealing Atmospheres on Photoelectrochemical Activity of TiO2 Nanotubes Modified with AuCu Nanoparticles
PublicationIn this article, we studied the annealing process of AuCu layers deposited on TiO2 nanotubes (NTs) conducted in various atmospheres such as air, vacuum, argon, and hydrogen in order to obtain materials active in both visible and UV–vis ranges. The material fabrication route covers the electrochemical anodization of a Ti plate, followed by thin AuCu film magnetron sputtering and further thermal treatment. Scanning electron microscopy...
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SnO2 nanoparticles embedded onto MoS2 nanoflakes - An efficient catalyst for photodegradation of methylene blue and photoreduction of hexavalent chromium
PublicationIn this work, a molybdenum disulfide/tin oxide (MoS2/SnO2) composite was successfully prepared via a hydrothermal method. The MoS2/SnO2 composite was used as a photocatalyst for photoreduction of hexavalent chromium and photodecomposition of methylene blue. It exhibited higher photocatalytic performance under simulated solar light irradiation than MoS2 itself. The obtained material was characterized by several spectroscopic and...
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Azo and azoxythiacrown ethers: synthesis and properties
PublicationA series of 16- and 18-membered azo- and azoxythiacrown ethers have been synthesized by reductive macrocyclization of the respective bis(nitrophenoxy)oxaalkanes. The aromatic residues located in the polyether region of the molecule were introduced to macrocyclic skeletons and their affinities toward different groups of metal cations in ion-selective electrodes were described. X-ray structures for one dinitropodand and one azoxybenzothiacrown...
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THE APPLICATION OF THE MECHANOCHEMICAL SYNTHESIS FOR THE PREPARATION OF ADVANCED CERAMICS BASED ON BARIUM TITANATE
PublicationIn the present study, the lead-free BaTi1-xZrxO3 (for x = 0, 0.05 and 0.15) ceramics were prepared by High-Energy Ball Milling and heat treatments. The performed X-ray, SEM and EDS measurements confirmed high purity, good quality and the expected quantitative composition of the obtained samples. The study of dielectric properties was performed by means of broadband dielectric spectroscopy at the frequency ranging from 0.1 Hz to...
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High temperature corrosion resistance of porous hastelloy alloy
PublicationTo further understand the suitability of Ni-Cr-base alloy for solid oxide fuel cell (SOFC), a commercial Ni-Cr-Fe-Mo alloy, Hastelloy X was selected and evaluated for oxidation behaviour under high temperature conditions. HastelloyX was chosen due to its unusual resistance to oxidizing, reducing and neutral atmospheres. For long term stability of metal supported fuel cell, the corrosion resistance plays a vital role and must be...
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Praseodymium Orthoniobate and Praseodymium Substituted Lanthanum Orthoniobate: Electrical and Structural Properties
PublicationIn this paper, the structural properties and the electrical conductivity of La1−xPrxNbO4+δ (x = 0.00, 0.05, 0.1, 0.15, 0.2, 0.3) and PrNbO4+δ are presented and discussed. All synthesized samples crystallized in a monoclinic structure with similar thermal expansion coefficients. The phase transition temperature between the monoclinic and tetragonal structure increases with increasing praseodymium content from 500 ◦C for undoped...
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Mg2+ Doping Effects on the Structural and Dielectric Properties of CaCu3Ti4O12 Ceramics Obtained by Mechanochemical Synthesis
PublicationIn this study, ceramic CaCu3Ti4O12 (CCTO) and CaCu3−xMgxTi4O12 solid solutions in which 0.1 ≤ x ≤ 0.5 were prepared by the mechanochemical method, realized by a high‐energy ball milling technique. The effects of the Mg2+ ion concentration and sintering time on the dielectric response in the prepared ceramics were investigated and discussed. It was demonstrated that, by the use of a sufficiently high energy of mechanochemical treatment,...
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Nano-structured Pt embedded in acidic salts of heteropolymolybdate matrices: MS EXAFS study
PublicationA structural study of Pt nano-catalysts is presented in the paper. The innovation in the case of the considered catalytic materials resides in the use a meso-microporous inorganic matrix of heteropolyacid salt of composition X2.5H0.5YMo12O40 where X = Rb, Cs and Y = P, Si as a catalyst support. Metallic nanoparticles were created by platinum ions reduction in a hot H2/Argon stream and were mainly located into matrix pores. As the...
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Tuning the photocatalytic performance through magnetization in Co-Zn ferrite nanoparticles
PublicationIn this work, the link between the photocatalytic performance of Co-Zn ferrite nanoparticles and the net magnetic moment is analyzed. CoxZn1-xFe2O4 nanoparticles (0 ≤ x ≤ 1) were synthesized by co-precipitation method and different physicochemical techniques were employed to characterize the samples (X-ray diffraction, Transmission Electron Microscopy (TEM), BET surface area, Diffuse Reflectance Spectroscopy (DRS), Photoluminescence spectroscopy,...
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Investigation of magnetic order in a new intermetallic compound Nd2PtGe3
PublicationIn the present study we report a successful synthesis of the new intermetallic compound Nd2PtGe3 by an arc-melting method. The powder X-ray diffraction analysis indicates that this compound crystallizes in an disordered variant of the AlB2-type structure (space group P6/mmm, no. 191) with lattice parameters a = 4.2455 Å and c = 4. 1933 Å. The compound exhibits a cluster-glass transition below Tf = 2.9 K, characterized through ac...
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Formation of intermetallic compounds in the solid-liquid composites of the Ga-Ni system
PublicationThe processes of formation of intermetallic compounds in the composite system of liquid gallium-nickel powder by the methods of x-ray diffraction, scanning electron microscopy and differential thermal analysis have been studied. A change in the phase composition was discovered and the influence of thermal treatment of the composites under investigation on the phase formation processes was analyzed. The mechanism of gallium enriched...
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Synthesis of 3-Carbamoyl b-Lactams via Manganese(III)-Promoted Cyclization of N-Alkenylmalonamides
PublicationManganese(III)-promoted cyclization of N-alkenylmalonamides (¼N-alkenylpropanediamides) gave 3-(aryl/(alkylamino)carbonyl) b-lactams as well as 3-(aryl/(alkylamino)thiocarbonyl) b-lactams. The relative configuration of the obtained products was unambiguously determined by X-ray crystallography. The proposed method is very useful for the one-pot synthesis of a number of 3-(aryl/ (alkylamino)carbonyl) b-lactams, especially those...
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Synthesis and structural characterization of novel 2-benzimidazolylthioureas: adducts of natural isothiocyanatesand 2-amino-1-methylbenzimidazole
PublicationNa drodze syntezy chemicznej uzyskano addukty naturalnych izotiocyjanianów - alilu, benzylu i fenyloetylu i 2-amino-1-metylobenzoimidazolu. W następstwie optymalizacji warunków reakcji, poszczególne 2-benzimidazolilotiomoczniki otrzymano produkty z umiarkowanymi wydajnościami. Strukturę molekularną i krystaliczną produktów scharakteryzowano przy użyciu metod spektroskopowych i X-ray. Analiza uzyskanych widm pozwoliła stwierdzić,...
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Structure and performance properties of environmentally-friendly biocomposites based on poly(ɛ-caprolactone) modified with copper slag and shale drill cuttings wastes
PublicationThe potential application of two types of industrial wastes, drill cuttings (DC) and copper slag (CS), as silica-rich modifiers of poly(ɛ-caprolactone) (PCL) was investigated. Chemical structure and physical properties of DC and CS fillers were characterized using X-ray diffractometer, X-ray fluorescence spectroscopy, particle size and density measurements. PCL/DC and PCL/CS composites with a variable content of filler (5 to 50...
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Photocatalytic activity of solvothermal prepared BiOClBr with imidazolium ionic liquids as a halogen sources in cytostatic drugs removal
PublicationIn this work, the BiOClBr, as a new family of bismuth based semiconductors, was successfully applied to remove of cytostatic drugs from water under UV-Vis light irradiation. BiOCl, BiOBr and BiOClBr were synthesized using two steps solvothermal method in glycerol. The inorganic salts (KCl and KBr) and 1-butyl-3-metylimidazolium chloride (BmimCl) and 1-butyl-3-metylimidazolium bromide (BmimBr) ionic liquids (ILs) were used as the...
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Morphology, Photocatalytic and Antimicrobial Properties of TiO2 Modified with Mono- and Bimetallic Copper, Platinum and Silver Nanoparticles
PublicationNoble metal nanoparticles (NMNPs) enhanced TiO2 response and extended its activity under visible light. Photocatalytic activity of TiO2 modified with noble metal nanoparticles strongly depends on the physicochemical properties of NMNPs. Among others, the differences in the size of NMNPs seems to be one of the most important factors. In this view, the effect of the metal’s nanoparticles size, type and amount on TiO2 photocatalytic...
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Thermal Transitions and Structural Characteristics of Poly(3,4-ethylenedioxythiophene/cucurbit[7]uril) Polypseudorotaxane and Polyrotaxane Thin Films
PublicationHerein, we report the thermal transitions and structural properties of poly(3,4-ethylenedioxythiophene/cucurbit[7]uril) pseudopolyrotaxane (PEDOT∙CB7-PS) and polyrotaxane (PEDOT∙CB7-PR) thin films compared with those of pristine PEDOT. The structural characteristics were investigated by using variable-temperature spectroscopic ellipsometry (VTSE), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and atomic force...
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Lanthanide co-doped TiO2: the effect of metal type and amount on surface properties and photocatalytic activity
PublicationPreparation of new rare earth metal-containing TiO2 nanocomposites (Nd3+/Er3+, Nd3+/Eu3+, Eu3+/Ho3+-TiO2) using sol–gel route and their photoactivity under visible and ultraviolet light is reported. The obtained photocatalysts were subsequently characterized by Brunauer–Emmett–Teller (BET) method, UV–Vis diffuse-reflectance spectroscopy (DRS), luminescence spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray powder diffraction...
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The supramolecular organization of self-assembling chlorosomal bacteriochlorophyll c, d, or e mimics
PublicationBacteriochlorophylls (BChls) c, d, and e are the main light-harvesting pigments of green photosynthetic bacteria that self-assemble into nanostructures within the chlorosomes forming the most efficient antennas of photosynthetic organisms. All previous models of the chlorosomal antennae, which are quite controversially discussed because no single crystals could be grown so far from these organelles, involve a strong hydrogen-bonding...
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The Influence of the Electrodeposition Parameters on the Properties of Mn-Co-Based Nanofilms as Anode Materials for Alkaline Electrolysers
PublicationIn this work, the influence of the synthesis conditions on the structure, morphology, and electrocatalytic performance for the oxygen evolution reaction (OER) of Mn-Co-based films is studied. For this purpose, Mn-Co nanofilm is electrochemically synthesised in a one-step process on nickel foam in the presence of metal nitrates without any additives. The possible mechanism of the synthesis is proposed. The morphology and structure...
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The influence of azide and imidazole on the properties of Mn- and Cd-based networks: conductivity and nonlinear phenomena
PublicationWe report a study on a family of four new Mn- and Cd-azide-imidazolate-based compounds with various crystal architectures. Notably, three of these compounds display noncentrosymmetric crystal arrangements at room temperature, a rare phenomenon in hybrid organic–inorganic materials. Both nonlinear optical (NLO) and electrical phenomena in these compounds are observed. The NLO processes include second and third harmonic generation,...
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Local atomic order in low Pt-content nanocatalysts investigated in situ by XAS
PublicationThe unique features of X-ray absorption spectroscopy allow investigations of nanosized catalysts for fuel cells under working conditions. We present the results of an experiment carried out on a low Pt content electrocatalyst supported by a mesoporous heteropolyacid salt and used at the cathode of a proton exchange membrane fuel cell (PEMFC). The analysis of the EXAFS signal at the Pt L3-edge indicates that upon operating the fuel...
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The reactivity of 1,1-dichloro-2,2-di-tert-butyldiphosphane towards lithiated metal carbonyls: a new entry to phosphanylphosphinidene dimers
PublicationReactions of [Cp*(OC)3M]Li (Cp* = C5Me5, M = Mo, W) towards t-Bu2P–PCl2 lead to the formation of phosphanylphosphinidene dimers [Cp*(OC)3M(η2-t-Bu2P–P)]2 in fairly good yields. The formation of a tetraphosphorus ligand proceeds via reductive dimerization of t-Bu2P–P units. NMR, X-ray investigations and DFT calculations show that the resulting tetraphosphorus ligand has a structure of dication t-Bu2P+=P–P=P+t-Bu2.
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Reactivity of triphosphinoboranes towards H3B·SMe2: access to derivatives of boraphosphacycloalkanes with diverse substituents
PublicationTriphosphinoboranes activated the B–H bond in the BH3 molecule without any catalysts at room temperature. Hydroboration reactions led to boraphosphacyloalkanes with diverse structures. The outcomes of reactions depend on the size of the phosphanyl substituent on the boron atom of the parent triphosphinoborane, where derivatives of boraphosphacyclobutane and boraphosphacyclohexane were obtained. Furthermore, the precursor of triphosphinoboranes,...