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Synthesis of hybrid zinc-based materials from ionic liquids: a novel route to prepare active Zn catalysts for the photoactivation of water and methane
摘要： A new and simple route for the preparation of zinc-based materials is proposed in this work. The synthesis of zinc oxide from the hydrolysis of imidazolium trichlorozincate ionic liquids (ILs) produces catalytic active nanostructured materials, where the size and shape (irregular particles, nanorods) are dependent on the synthetic conditions employed. Indeed, the hydrolysis of trichlorozincate ILs prepared by an equimolar ionic liquid:ZnCl2 ratio afforded irregular particles, while increasing the IL amount (2:1 and 4:1) drives to the formation of nanorods. These hybrid zinc oxide materials were able to promote the photoactivation of water and methane at 25 °C affording up to 1417 μmolH2.g-1.h-1 and up to 67 μmolCO2.g-1.h-1, respectively. Moreover, tuning the reaction conditions a microstructured zinc-based mineral named simonkolleite was prepared with the expected hexagonal-like morphology. This compound was also applied as an alternative and efficient photocatalyst in the activation of water (972 μmolH2.g-1.h-1) and methane (12.6 μmolCO2.g-1.h-1).
关键词： Zinc oxide,photocatalysis,semiconductors,simonkolleite,ionic liquids,nanomaterials
更新于2025-11-21 11:18:25
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Electrodeposition of lead selenide films from ionic liquids based on choline chloride
摘要： The paper presents some experimental results regarding the electrodeposition of PbSe thin films at 70 oC from two choline chloride (ChCl) based ionic liquids containing PbCl2 and SeO2 as precursors in choline chloride-ethylene glycol (ILEG) and choline chloride-urea (IL) eutectic mixtures. In this article we will detail our investigation of cathodic processes involved during the electrodeposition of binary semiconductor compound, PbSe as well as of singular Pb and Se elements. The cathodic branches of the recorded cyclic voltammograms in the cases of ionic liquids containing both Pb2+ + Se4+ show successively the Se underpotential deposition, Se bulk deposition and Pb deposition followed by a formation of PbSe semiconductor compound. However, at the most negative potentials the Se content of final layers decreases by a partial electrochemical dissolution of Se which reduces to Se2- soluble species. PbSe thin films have been electrodeposited on copper or nickel substrates under potentiostatic control at 70 oC for 0.5-4 h. The adherent and uniform deposits were characterized by SEM-EDX and XRD techniques. SEM images have shown adherent and grey deposits with uniform morphology and cubic PbSe crystals. A stoichiometry of around Pb1.1Se was indicated by EDX elemental analysis. XRD confirmed the formation of PbSe compound, showing a nanocrystalline structure, with crystallites average sizes in the range of 10-35 nm.
关键词： DES ionic liquids,electrodeposition,selenide semiconductors,Lead selenide,cyclic voltammetry
更新于2025-09-23 15:23:52
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Facile synthesis of silver-polypyrrole nanocomposites: Use of ionic liquid as solvent and template
摘要： In this study we show a facile method to synthesize nanocomposites of PPY and silver from the direct oxidation of pyrrole by silver cations from silver bis(trifluoromethanesulfonyl)imide (AgTf2N), using 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMImTf2N) as solvent and template to the hybrid material formation. Some synthesis parameters, such as initial concentration of the oxidant agent (C) and oxidant-to-monomer molar ratio (K) were varied in order to evaluate their influence on the final product. The black powders obtained, according to the characterization results, contain doped polypyrrole and silver nanoparticles amounts ranged from 26 to 36 wt%, depending on the C and K parameters utilized in the syntheses. The measured electrical conductivity values of the samples were in the order of 10-2 S cm-1, which classify the hybrid materials as semiconductor. By adding the HTf2N acid to the synthesis, a sample with more elevated electrical conductivity (0.12 S cm-1) was obtained, caused by the higher protonation degree of the oxidized units in the polymer.
关键词： Polypyrrole,Nanocomposite,Ionic liquids,Silver nanoparticles
更新于2025-09-23 15:23:52
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Ionic Gating of Ultrathin and Leaky Ferroelectrics
摘要： Ionic liquids are used to induce reversible large area polarization switching in ultrathin and highly defective ferroelectric films. Long range electrostatic charge control is induced by modifying the electric double layer at an ionic liquid–PbZr0.2Ti0.8O3 interface with electrostatic and electrochemical control of polarization orientation in the ferroelectric layer. The localized nature of the ionic gating mechanism prohibits the presence of leakage current, which has historically limited the switching of ultrathin and/or electrically leaky ferroelectric films in solid metal-gated capacitor devices. This is demonstrated on ultrathin films and in massively defective films with >30% coverage of direct conducting channels running from surface to ground. This approach opens new design possibilities for integrating ultrathin ferroelectric films in functional electronic devices.
关键词： ferroelectrics,polarization switching,ionic liquids,ionic gating,device structure
更新于2025-09-23 15:22:29
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Photodetachment, electron cooling, and recombination, in a series of neat aliphatic room temperature ionic liquids
摘要： Transient absorption following photodetachment of a series of neat methyl-alkyl-pyrrolidinium bis(trifluoromethylsulfonyl)amides at 6.20 eV was measured with sub-picosecond time resolution in the visible and near-IR portions of the spectrum. This series spans the onset of structuring in the liquids in the form of polarity alternation. Excitation promotes the electron into a delocalized state with a very large reactive radius. Strong transient absorption is observed in the visible spectrum with a ～700 fs lifetime, and much weaker, long-lived absorption is observed in the near-IR spectrum. Absorption in the visible is shown to be consistent with the hole, and absorption in the near-IR is assigned to the free solvated electron. Yield of free electrons is estimated at ～4%, is insensitive to the size of the cation, and is determined in less than 1 ps. Solvation of free electrons depends strongly on the size of the cation and correlates well with the viscosity of the liquid. In addition to radiolytic stability of the aliphatic cations, ultrafast, efficient recombination of separated charge in NTf2? based ionic liquids following photo-excitation near the band-gap may prevent subsequent reactive damage associated with anions.
关键词： solvated electron,electron cooling,recombination,photodetachment,ionic liquids,transient absorption
更新于2025-09-23 15:22:29
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Plasmon-Enhanced Photodegradation of Ionic Liquids with Ag Nanocubes/ZnO Microsphere Composites
摘要： Ionic liquids (ILs) have been a hot topic in the past decades because of their unique properties and promising applications in various areas. However, the toxicity of ILs and their possible risk to the environment and aquatic organisms have also been confirmed. Therefore, it is imperative to seek an efficient way to remove or degrade ILs in the polluted aqueous system. In this work, Ag nanocubes/ZnO microspheres composites have been designed, prepared, and used for the photocatalytic degradation of eight commonly used imidazolium-based ILs in aqueous solution. It is found that ZnO semiconductor photocatalyst with an Ag content of 1.12 at. % can degrade 90% of all these ILs within 7 h. The structural characterization, photoluminescence analysis, and discrete dipole approximation calculations showed that the loading of Ag nanocubes onto ZnO microspheres significantly improves the performance of ZnO for the IL degradation through hot electron transfer and electrical field enhancement. In addition, the formed intermediates in the degradation process of [C4 mim]Cl have been detected by gas chromatography?mass spectroscopy. A possible degradation mechanism is proposed and compared with those previously reported in the chemical degradation.
关键词： Photodegradation,Ionic liquids,Plasmon-enhanced,ZnO microspheres,Ag nanocubes
更新于2025-09-23 15:21:21
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Extremely Soft, Conductive, and Transparent Ionic Gels by 3D Optical Printing
摘要： A series of 3D printable multifunctional ionic gels (IGs) are developed incorporating ionic liquid (IL) in the thiol–ene network of thiol-based end-crosslinker and acrylate monomers. The resulted gels, termed as thiol-ionic gels (T-IGs), are highly transparent and very soft with IL content of 70–85 wt%. The mechanical and conductive properties of the T-IGs are found to be largely dependent on the IL content, end-crosslinker functionalities, and chain-length of monomers. Progression of ionic conductivity is observed with an increase in IL content and conductivity as high as 5.40 mS cm?1 is attained for longer acrylate group containing T-IGs at room temperature, while further increase is observed at elevated temperature. T-IGs in all systems are found to exhibit superior thermal stability. Three-dimensional fabrication of these functional T-IGs is achieved by optical 3D printing process with microscale resolution in facile steps.
关键词： multifunctional ionic gels,3D printing,thiol–ene reaction,ionic liquids
更新于2025-09-23 15:21:01
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Synthesis of plasmonic Fe/Al nanoparticles in ionic liquids
摘要： Bottom-up and top-down approaches are described for the challenging synthesis of Fe/Al nanoparticles (NPs) in ionic liquids (ILs) under mild conditions. The crystalline phase and morphology of the metal nanoparticles synthesized in three different ionic liquids were identified by powder X-ray diffractometry (PXRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), selected-area electron diffraction (SAED) and fast Fourier transform (FFT) of high-resolution TEM images. Characterization was completed by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) for the analysis of the element composition of the whole sample consisting of the NPs and the amorphous background. The bottom-up approaches resulted in crystalline FeAl NPs on an amorphous background. The top-down approach revealed small NPs and could be identified as Fe4Al13 NPs which in the IL [OPy][NTf2] yield two absorption bands in the green-blue to green spectral region at 475 and 520 nm which give rise to a complementary red color, akin to appropriate Au NPs.
关键词： plasmonic properties,bottom-up synthesis,ionic liquids,Fe/Al nanoparticles,top-down synthesis
更新于2025-09-23 15:21:01
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Ionic Liquid Stabilized Gelatin-Lignin Films: A potential UV Shielding Material with Excellent Mechanical and Antimicrobial Properties
摘要： Significant research is going on to develop environmental friendly UV shielding materials. Herein, we have constructed choline citrate (a bio-based ionic liquid, IL) stabilized homogeneous gelatin-lignin UV shielding films with excellent antimicrobial and mechanical properties. Synthesis procedure of films is less energy demanding, one pot and sustainable in nature. Prepared films are characterized for its mechanical and thermal analysis using UTM and TGA respectively. ATR-IR and PXRD is employed to explore the possible formation of H-bonding between biopolymers and IL and change in crystallinity in films after addition of IL to gelatin-lignin matrix. Surface morphology of prepared films has been studied using optical microscope, AFM and FE-SEM. Optical properties of prepared films are measured using UV-Visible spectroscopy. Antimicrobial activity of prepared films has been tested against Bacillus subtilis.Prepared bio-films have shown sun protection factor (SPF) up to ~ 45.0, large elongation ~200% and tensile strength ~70 MPa, which are as good as exhibited by organic polymeric films, indicating a promising renewable resources-based material for UV-light-blocking.
关键词： UV blocking material,Composite,biomass,lignin gelatin composite,ionic liquids
更新于2025-09-23 15:21:01
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Understanding the Microscopic Behavior of Binary Mixtures of Ionic Liquids Through Various Spectroscopic Techniques
摘要： In recent times it has been shown that certain binary mixture of pure ionic liquids having appropriate chemical composition can behave like a new chemical entity. However, current knowledge about the microscopic behavior of these interesting systems is rather limited. The present study is undertaken with an objective to understand the microscopic behavior in terms of intermolecular interaction, structure and dynamics of these systems. In the present study, few (IL+IL) mixtures are chosen with a common cation and a variation of anion. The investigations are also carried out by taking individual pure ILs so that the difference in behavior between pure IL and (IL+IL) mixtures are understood. Initially the systems have been investigated by studying the thermophysical properties of the concerned mixtures. Synergistic effect between combining pure ILs through photochromism has also been studied. These mixtures have been investigated further through steady state and time resolved fluorescence spectroscopy, electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR) and fluorescence correlation spectroscopy (FCS). Interestingly, time-resolved fluorescence data also pointed out that (IL+IL) mixtures are not only spatially heterogeneous but they are dynamically heterogeneous too. EPR measurements have suggested that the micro-polarity (ET(30)) of (IL+IL) mixture is close to aliphatic polyalcohol. Measurements of translational diffusion coefficients of the diffusing species through NMR and FCS studies have provided idea about the nano-structural organization within (IL+IL) binary mixtures. The analysis of data essentially reveals that the mixtures of ILs that are used in the current study do not behave like a non-ideal solution. The behavior of the IL mixtures is observed to be more like quasi-ideal type.
关键词： thermophysical properties,binary mixtures,EPR,FCS,fluorescence spectroscopy,NMR,Ionic liquids,photochromism,spectroscopic techniques
更新于2025-09-23 15:21:01