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Eu-doped layered yttrium hydroxides sensitized by series of benzenedicarboxylate and sulphobenzoate anions
摘要： A number of Eu-doped layered yttrium hydroxides intercalated with various benzenedicarboxylate (phthalate, isophthalate and terephthalate) and sulphobenzoate (2-, 3- and 4-sulphobenzoate) anions was obtained using hydrothermal microwave (HTMW) treatment. For the first time, phthalate, isophthalate and sulphobenzoate anions were intercalated into layered rare-earth hydroxides (LRHs). Two approaches to the synthesis of intercalated layered yttrium hydroxides were used: ion exchange reactions and homogeneous hydrolysis of rare-earth cations in the presence of the intercalated anion. Ion-exchange reactions between layered rare-earth hydroxides and a series of benzenedicarboxylic and sulphobenzoic acid salts were performed under conditions of HTMW treatment, which significantly increased the rate of intercalation. The structure of the first representative of layered rare-earth hydroxides intercalated with sulphobenzoate-type anions, namely layered yttrium hydroxide intercalated with 4-sulphobenzoate of composition Y3(OH)7(C7H4O5S)·H2O, was solved. Intercalation of benzenedicarboxylate and sulphobenzoate anions into Eu-doped layered yttrium hydroxides led to a substantial sensitization of Eu3+ luminescence. The local symmetry of Eu3+ was greatly decreased by intercalation of benzenedicarboxylate and sulphobenzoate anions.
关键词： Layered rare-earth hydroxides,anion exchange,LRH,hydrothermal microwave treatment,luminescence,hybrid materials
更新于2025-11-21 11:20:42
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Saponification Precipitation Method of CsPbBr3 Nanocrystals with Blue-Green Tunable Emission
摘要： We report on a new synthesis process for halide perovskite nanoplatelets and nanoplates that switches the production process of the cesium precursor from a fatty acid/cesium salt reaction to a cesium base/fatty acid ester reaction, thus enabling the reaction to occur in ambient conditions in minutes instead of hours. The saponification precipitation process reported here, as a result, does not require a vacuum oven or inert reaction environment in obtaining the cesium precursor, or any part of the reaction. Furthermore, the process creates a hygroscopic byproduct that results in a self-drying synthesis. The obtained perovskite nanocrystals exhibit a blue-green tunable emission that occurs via quantum confinement effect, phase, and morphology change. The consequence of these physical processes is that the band gap is highly tunable with temperature and the resulting nanocrystals show remarkable optical properties, while greatly simplifying the production of halide perovskite nanoplatelets and nanoplates.
关键词： Blue-Green Tunable Emission,Saponification Precipitation Method,Hybrid Materials,Magnetic,CsPbBr3 Nanocrystals,Plasmonics,Optical
更新于2025-11-19 16:46:39
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Biocompatible organic–inorganic hybrid materials based on nucleobases and titanium developed by molecular layer deposition
摘要： We have constructed thin films of organic–inorganic hybrid character by combining titanium tetra-isopropoxide (TTIP) and the nucleobases thymine, uracil or adenine using the molecular layer deposition (MLD) approach. Such materials have potential as bio-active coatings, and the bioactivity of these films is described in our recent work [Momtazi, L.; Dartt, D. A.; Nilsen, O.; Eidet, J. R. J. Biomed. Mater. Res., Part A 2018, 106, 3090–3098. doi:10.1002/jbm.a.36499]. The growth was followed by in situ quartz crystal microbalance (QCM) measurements and all systems exhibited atomic layer deposition (ALD) type of growth. The adenine system has an ALD temperature window between 250 and 300 °C, while an overall reduction in growth rate with increasing temperature was observed for the uracil and thymine systems. The bonding modes of the films have been further characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction, confirming the hybrid nature of the as-deposited films with an amorphous structure where partial inclusion of the TTIP molecule occurs during growth. The films are highly hydrophilic, while the nucleobases do leach in water providing an amorphous structure mainly of TiO2 with reduced density and index of refraction.
关键词： bioactive materials,ALD,MLD,hybrid materials,nucleobases
更新于2025-11-14 15:14:40
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Coupling of Fluorophores in Single Nanoapertures with Tamm Plasmon Structures
摘要： Metal nanostructures (such as plasmonic antennas) have been widely demonstrated to be excellent devices for beaming and sorting the fluorescence emission. These effects rely on the constructive scattering or diffraction from different elements (such as metal corrugations or nanorings) of the nanostructures. However, subwavelength-size nanoholes, without nearby nanoscale features, results in an angularly dispersed emission from the distal surface. Herein, we demonstrate for the first time the emission redirection capabilities of a single isolated nanoaperture milled in a thick silver film deposited on a dielectric multilayer. Specifically, we show that a dye dissolved in ethanol filling in the nanoaperture can couple to Tamm Plasmon Polariton (TPP) modes of the structure. Due to the small in-plane wavevectors of the TPPs, the fluorescence from Tamm-coupled dyes within the nanoaperture is emitted normally to the sample surface, with a minimum angular width of about 12.54o. This kind of fluorescence manipulation has proven to be effective with various nanoaperture shapes, such as circles, squares, and triangles. Our work is also the first experimental demonstration of lateral coupling of fluorophores with TPPs in nanoholes, with potential applications in bioanalysis and biosciences.
关键词： Optical,Plasmonics,and Hybrid Materials,Magnetic
更新于2025-09-23 15:23:52
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Angular-Dependent Spontaneous Emission in Cholesteric Liquid Crystal Films
摘要： Due to the presence of a selective reflection band, cholesteric liquid crystals (CLCs) strongly modify the emission of fluorescent guest molecules. While emission along the helical axis is well understood, the emission properties at oblique angles with respect to the cholesteric helix have so far have not been explored in detail. We present a systematic study of the angular-dependent spontaneous emission properties of dye-doped cholesteric films, including a full Stokes analysis of the emitted light. Variation of the cholesteric pitch allows us to probe the effect of the photonic band structure on spontaneous emission in a wide angular range. We find exceptional angular-dependent intensity and polarization variations of the emitted light, and give experimental proof for the splitting of the first-order reflection band as well as its overlap with the second-order band at large detection angles.
关键词： and Hybrid Materials,Optical,Cholesteric Liquid Crystal,Stokes Analysis,Angular-Dependent,Plasmonics,Spontaneous Emission,Magnetic
更新于2025-09-23 15:23:52
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Luminescent hybrid materials based on metal-organic phosphors in PbF2 powder and PbF2-containing glass matrix
摘要： The new hybrid materials (HM's) are based on the phosphors used in OLED technology in inorganic PbF2-containing matrices: PbF2 powders and low melting PbF2-based oxyfluoride glasses, were synthesized. We used highly effective thermostable phosphors: 4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluoro-1- (1-methyl-1H-pyrazol-4-yl) nonane-1,3-dione - (1,10-phenanthroline) europium (III), 8-hydroxyquinoline complexes with metals and the individual organic ligand – 4,4,4-trifluoro-1- (2-naphthyl) butane-1,3-dione. Powdered HM's were prepared by co-precipitation from aqueous solutions. The effect of organic molecules or molecular fragments on dimension and morphology of precipitated PbF2 particles, the luminescence properties of HM's were investigated for the samples obtained directly after the precipitation-drying procedure, and after the powders' calcination procedure. The change in the photoluminescence spectra after the heat treatment of the powders is caused by the proceeding of the exchange reaction between the metal complex and the matrix with the formation of Pb-complexes of different coordination is shown. HM (glasses PbF2eB2O3, PbF2eB2O3eSiO2 or PbF2eB2O3eSiO2eZnO phosphor) were obtained by the melt process in which the phosphor powder was submerged into the melt of the pre-synthesized glasses.
关键词： Lead fluoride,Lead fluoride nanoparticles,Hybrid materials,Luminescence,Organic phosphors
更新于2025-09-23 15:22:29
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Enhanced Photocatalytic Hydrogen Evolution with TiO <sub/>2</sub> -TiN Nanoparticle Composites
摘要： Metal nitrides have potential in energy applications due to their physical and optical properties. Nanoparticle composites of titanium nitride (TiN) and titanium dioxide (TiO2) were investigated for their photocatalytic hydrogen (H2) activity via methanol reformation. Physical mixing of the nanoparticulate TiO2 and TiN was employed to prevent the oxy-nitride formation and particle aggregation observed in thermal preparations. This convenient combination of TiO2 and TiN demonstrated a substantial synergistic effect with enhanced activity (9.4 μmol/h TiO2-TiN vs 1.8 μmol/h TiO2) under combined UV/Vis light. Irradiation under only UV light resulted in a similar enhancement factor compared to using combined UV/Vis light, demonstrating that the enhanced activity of the composites occurs essentially for UV-driven photocatalysis. No activity/enhancement was observed with only visible light irradiation, however, minor enhancement was observed when switching between UV and UV/Vis irradiation, suggesting a contribution from the TiN plasmon. We propose that the plasmonic contribution is dependent on the band gap excitation of TiO2, which reduces the degree of band bending at the TiO2/TiN interface. This promotes the migration of hot electrons from TiN away from the TiO2/TiN interface to be used for H2 evolution.
关键词： TiO2-TiN Nanoparticle Composites,Plasmonics,Optical,Magnetic,and Hybrid Materials,Photocatalytic Hydrogen Evolution
更新于2025-09-23 15:22:29
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Plasmonic Sensing of Refractive Index and Density in Methanol-Ethanol Mixtures at High Pressure
摘要： The localized surface plasmon resonance (LSPR) of gold nanospheres dispersed in methanol-ethanol 4:1 was measured as a function of pressure up to 60 GPa. The LSPR exhibits an intense redshift with pressure in the range of 0-10 GPa, followed by a slower blueshift at higher pressures. This is because an increase in the solvent refractive index with pressure leads to a redshift of the LSPR peak wavelength while an increase in the electron density of the gold nanospheres with pressure leads to a blueshift. Solvent solidification at 10 GPa and associated non-hydrostatic effects have a negligible influence on the LSPR shifts in the case of nanospheres. Here we show that both the LSPR shifts and changes in the nanospheres absorption coefficient can be explained on the basis of Gans’ model, and this enables the solvent refractive index and the density of the solvent to be determined across the hydrostatic pressure range from 0-60 GPa. Interestingly, plasmonic sensing shows no evidence of crystallization or glass phase transitions in MeOH-EtOH (4:1) solvents within the explored pressure range.
关键词： High Pressure,Optical,Hybrid Materials,Methanol-Ethanol Mixtures,Density,Plasmonics,Magnetic,Refractive Index
更新于2025-09-23 15:21:01
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Periodic ZnO-Elevated Gold Dimer Nanostructures for Surface-Enhanced Raman Scattering Applications
摘要： The electron beam lithography-defined periodic ZnO-elevated gold dimer nanostructures for surface-enhanced Raman spectroscopy with strong electromagnetic field enhancements were fabricated in the present work. The ZnO nanorods (NRs) were grown on the patterned substrate using the hydrothermal process and Au dimers were deposited on the top surface of ZnO NRs, forming suspended gold dimers and providing plasmonic hot-spots with nanocavity effect. The effects of dimer radius, gap size and ZnO NR height on the dark-field scattering spectra and surface-enhanced Raman scattering (SERS) were investigated experimentally and theoretically. The SERS response was enhanced with increasing dimer radius and decreasing gap size. The SERS enhancement factor (EF) due to the localized surface plasmon resonance was calculated from simulation results. The calculated EF as a function of ZnO NR height showed the periodic trend of electric field intensity with the periodicity of about half of the exciting laser wavelength, and was in agreement with SERS measurements. Our hybrid substrates combining plasmonic nanocavity effect with charge transfer across the heterojunction denoted the potential candidate for SERS applications.
关键词： Plasmonics,Surface-Enhanced Raman Scattering,ZnO-Elevated Gold Dimer Nanostructures,Magnetic,Optical,and Hybrid Materials
更新于2025-09-23 15:21:01
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Large Performance Enhancement in All-Solution-Processed, Full-Color, Inverted Quantum Dot Light-Emitting Diodes by Using Graphene Oxide-Doped Hole Injection Layer
摘要： Solution-processed hole injection layers (HILs) for full-color, inverted quantum dot light-emitting diodes (QLEDs) are developed by simply incorporating the graphene oxide (GO) into poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). The excellent wettability of the GO-doped PEDOT:PSS mixture facilitates the effective deposition of HIL onto the organic underlayer. Ultraviolet photoelectron spectroscopy and Raman spectroscopy characterization reveal that the GO-doped PEDOT:PSS HIL possesses the advantages of increased work function and improved conductivity. Thus, the GO-doped PEDOT:PSS HIL can promote hole injection from the top anode into the device by reducing the hole injection barrier and sheet resistance. As a result, by using the GO-doped PEDOT:PSS HIL, we have successfully demonstrated highly bright all-solution-processed, full-color, inverted QLEDs showing remarkably enhanced luminance of 142165, 63318, and 3019 cd/m2 for green, red, and blue devices, respectively. To the best of our knowledge, the green device’s luminance is the best for all-solution-processed inverted green QLEDs. These results suggest that the GO-doped PEDOT:PSS is a promising candidate for high-quality HIL in all-solution-processed QLEDs with an inverted structure.
关键词： Optical,Quantum Dot Light-Emitting Diodes,Hole Injection Layer,Plasmonics,Magnetic,Hybrid Materials,Graphene Oxide,PEDOT:PSS
更新于2025-09-23 15:21:01