Ionic Liquid-assisted Synthesis Research Articles

Ionic Liquid-Assisted Synthesis of Higher Loaded Ni/Fe Dual-Atom Catalysts in N, F, B Codoped Carbon Matrix for Accelerated Sulfur Reduction Reaction.

In response to mitigating the severe shuttle effect within lithium-sulfur batteries, single-atom catalysts have emerged as one of the most effective solutions. Here, N, F, B codoped porous hollow carbon nanocages (NFB-NiFe@NC) with high Ni and Fe doping are rationally designed and synthesized using ionic liquids (ILs) as dopants. The introduction of ILs inhibits the growth of zeolitic imidazolate framework-8 (ZIF8), resulting in NFB-ZIF8 precursors with smaller particle sizes, enabling higher loading dual-atom catalysts. Meanwhile, the abundant heteroatoms increase the reactive sites and alter the carbon matrix's nonpolar intrinsic properties, thus enhancing the chemisorption of polysulfides. The synergistic interaction of the heteroatoms with Ni and Fe dual-atoms ultimately promotes the catalytic conversion kinetics of polysulfides. As a result of these beneficial properties, the cells prepared using the NFB-NiFe@NC modified separator exhibit significantly improved performance, including a high initial capacity of 1448 mAh g-1 at 0.2 C. Even at a high S-loading of 7.6 mg cm-2, the ideal area capacity of 8.38 mAh cm-2 can still be maintained at 0.1 C. New insights are provided here for designing highly loaded dual-atom catalysts for application in lithium-sulfur batteries.

Ionic liquid‐assisted synthesis of N, F, and B co‐doped BiOBr/Bi2Se3 on Mo2CTx for enhanced performance in hydrogen evolution reaction and supercapacitors

Heteroatom doping and heterojunction formation are effective strategies to enhance electrochemical performance. In this study, we present a novel approach that utilizes an ionic liquid-assisted synthesis method to fabricate a BiOBr-based material, which is subsequently loaded onto Mo2CTx via a selenization treatment to create a BiOBr/Bi2Se3 heterostructure, denoted as NBF-BiOBr/Bi2Se3/Mo2CTx. The incorporation of heteroatoms improves its hydrophilicity and electronegativity, while the formation of heterojunctions adjusts the electronic structure at the interface, resulting in lower OH–/H+ adsorption energy. The specific surface area of NBF-BiOBr/Bi2Se3/Mo2CTx is 193.1 m2/g. In hydrogen evolution reaction (HER) tests, NBF-BiOBr/Bi2Se3/Mo2CTx exhibits exceptional catalytic performance in acidic media, requiring only an overpotential of 109 mV to achieve a current density of 10 mA cm−2. Furthermore, NBF-BiOBr/Bi2Se3/Mo2CTx demonstrates superior electrochemical performance in an asymmetric supercapacitor, with an energy density as high as 55.6 Wh kg−1 at a power density of 749.9 Wh kg−1. This work provides a novel approach for heteroatom doping and heterojunction synthesis, offering promising prospects for further advancements in the field.

Increasing the number of active centers and matching acid micro-environment by the design of phosphorus immobilized for boosting catalytic activity

A series of MnMoP catalysts were prepared by ionic liquid assisted thermal synthesis method and characterized by Powder X-ray diffraction, Fourier Transform Infrared Spectrometer, Scanning Electron Microscope, X-ray Photoelectron Spectroscope and NH3-Temperature Programmed Desorption. The catalytic performance of MnMoP catalysts for the synthesis of cyclohexene oxide (CHO) was studied. The results showed that phosphorus was fixed via ionic liquid, which could improve the catalytic performance of the catalysts. Under the optimal conditions, MnMoP-80 catalyst showed the best catalytic performance with the cyclohexene conversion of 97.5% and CHO selectivity of 93.9%. Meanwhile, we have deduced that the reaction was mainly carried out according to the epoxidation pathway over MnMoP catalyst.

Hydrophilic ionic liquid assisted hydrothermal synthesis of ZnO nanostructures with controllable morphology.

Nanostructured ZnO with controllable morphology was prepared by a hydrothermal method in the presence of three different hydrophilic ionic liquids (ILs), 1-ethyl-3-methylimidazolium methylsulfate, ([C2mim]CH3SO4), 1-butyl-3-methylimidazolium methylsulfate, ([C4mim]CH3SO4) and 1-ethyl-3-methylimidazolium ethylsulfate, ([C2mim]C2H5SO4) as soft templates. The formation of ZnO nanoparticles (NPs) with and without IL was verified using FT-IR and UV-visible spectroscopy. X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns indicated the formation of pure crystalline ZnO with a hexagonal wurtzite phase. Field emission scanning electron microscopic (FESEM) and high-resolution transmission electron microscopic (HRTEM) images confirmed the formation of rod-shaped ZnO nanostructures without using IL, whereas the morphology varied widely following addition of ILs. With increasing concentrations of [C2mim]CH3SO4, the rod-shaped ZnO nanostructures transformed into flower-shaped nanostructures whereas with rising concentrations of [C4mim]CH3SO4 and [C2mim]C2H5SO4 the morphology changed into petal- and flake-like nanostructures, respectively. The selective adsorption effect of the ILs could protect certain facets during the formation of ZnO rods and promote the growth in directions other than [0001] to yield petal- or flake-like architectures. The morphology of ZnO nanostructures was, therefore, tunable by the controlled addition of hydrophilic ILs of different structures. The size of the nanostructures was widely distributed and the Z-average diameter, evaluated from dynamic light scattering measurements, increased as the concentration of the IL increased and passed through a maximum before decreasing again. The optical band gap energy of the ZnO nanostructures decreased when IL was added during the synthesis which is consistent with the morphology of the ZnO nanostructures. Thus, the hydrophilic ILs serve as self-directing agents and soft templates for the synthesis of ZnO nanostructures and the morphology and optical properties of ZnO nanostructures are tunable by changing the structure of the ILs as well as systematic variation of the concentration of ILs during synthesis.

In situ growth of hierarchical NiO microspheres via ionic liquid-assisted synthesis for ppb-level detection of H2S

Well-defined hierarchical NiO microspheres were in situ deposited on ceramic tubes by a simple ionic liquid (IL)-assisted solvothermal method with subsequent calcination, and the characterization was exclusively confirmed through XRD, SEM, TEM and nitrogen adsorption-desorption techniques. Morphological characterization demonstrated that the nanostructures were constructed of interlaced porous nanosheets. Such NiO microspheres in situ grew onto ceramic tubes to form deposited film sensors, which displayed enhanced H2S sensing properties compared with the coated film sensors painted with the powder prepared in the same reaction system. Specifically, the deposited film sensor achieved a response value of 154.2–100 ppm H2S at a low working temperature of 92 °C, a fast recovery time of 7.5 s, with the lowest detection limit of 0.1 ppb. The excellent sensing performance should be attributed to the superior reactivity of the porous hierarchical architecture with large specific surface area, which facilitated the gas molecules to adsorb onto the surface and the consequent electron transfer. The reaction mechanism of the sensor to H2S was also discussed in detail based on XPS analysis, and was eventually interpreted as the two different kinds of kinetics occurring simultaneously: the oxidation of H2S molecules by chemisorbed oxygen, and the NiS formation along with the reaction of H2S with NiO.

Ionic liquid-assisted synthesis of cobalt‑iron difluoride electrocatalysts for oxygen evolution reaction

Surface reconstruction is a promising approach to obtain highly efficient electrocatalysts for oxygen evolution reaction (OER), which is vital for many renewable energy conversion and storage processes. Herein, we synthesized CoFe based difluoride by a simple solvothermal treatment process with the assistance of an ionic liquid ([Bmim]BF4). The final sample originated from Co0.67Fe0.33F2 demonstrated the highest electrocatalytic activity, generating a current density of 10 mA/cm2 at an overpotential of 270 mV. The appropriate amount of iron dopant can increase the number of active sites. Besides, the in-situ leaching of fluorine accompanied with OER was found to generate metal oxyhydroxide layer with abundant oxygen vacancies, thus leading to the high performance of the electrocatalysts.

Ionic liquid-assisted synthesis of chitin–ethylene glycol hydrogels as electrolyte membranes for sustainable electrochemical capacitors

A novel chitin–ethylene glycol hybrid gel was prepared as a hydrogel electrolyte for electrical double-layer capacitors (EDLCs) using 1-butyl-3-methylimidazolium acetate [Bmim][Ac] as a chitin solvent. Examination of the morphology and topography of the chitin–EG membrane showed a homogeneous and smooth surface, while the thickness of the membrane obtained was 27 µm. The electrochemical performance of the chitin–EG hydrogel electrolyte was investigated by cyclic voltammetry and galvanostatic charge/discharge measurements. The specific capacitance value of the EDLC with chitin–EG hydrogel electrolyte was found to be 109 F g−1 in a potential range from 0 to 0.8 V. The tested hydrogel material was electrochemically stable and did not decompose even after 10,000 GCD cycles. Additionally, the EDLC test cell with chitin–EG hydrogel as electrolyte exhibited superior capacitance retention after 10,000 charge/discharge cycles compared with a commercial glass fiber membrane.

Ionic liquid-assisted synthesis of tri-functional ruthenium oxide nanoplatelets for electrochemical energy applications

Ionic liquid-assisted synthesis of tri-functional ruthenium oxide nanoplatelets for electrochemical energy applications

Critical Role of Removing Impurities in Nickel Oxide on High-Efficiency and Long-Term Stability of Inverted Perovskite Solar Cells.

The performance enhancement of inverted perovskite solar cells applying nickel oxide (NiOx ) as the hole transport layer (HTL) has been limited by impurity ions (such as nitrate ions). Herein, we have proposed a strategy to obtain high-quality NiOx nanoparticles via an ionic liquid-assisted synthesis method (NiOx -IL). Experimental and theoretical results illustrate that the cation of the ionic liquid can inhibit the adsorption of impurity ions on nickel hydroxide through a strong hydrogen bond and low adsorption energy, thereby obtaining NiOx -IL HTL with high conductivity and strong hole-extraction ability. Importantly, the removal of impurity ions can effectively suppress the redox reaction between the NiOx film and the perovskite film, thus slowing down the deterioration of device performance. Consequently, the modified inverted device shows a striking efficiency exceeding 22.62 %, and superior stability maintaining 92 % efficiency at a maximum power point tracking under one sun illumination for 1000 h.

Ionic liquid-assisted synthesis of 2D porous lotus root slice-shaped NiO nanomaterials for selective and highly sensitive detection of N2H4

The sensitive and effective detection of Hydrazine (N2H4), a highly toxic compound, has been urgently required to ensure safe manufacture and physical health. In this work, a 2D porous lotus root slice-shaped NiO material was prepared by the ionic liquid-assisted hydrothermal method of 1-hexadecyl-3-methylimidazole chloride with regulated calcination temperature, and the characterization was exclusively confirmed through TG, XRD, SEM, TEM, XPS, and other test methods. The gas-sensing test results demonstrated that the small amount of ionic liquid residues in the NiO material after being calcined at 700 °C significantly improved its gas-sensing performance to N2H4 gas. The fabricated sensor achieved a response value of 107.6–100 ppm N2H4 at an optimal working temperature of 92 °C, a recovery time of 29.6 s, with the lowest detection limit of 10 ppb. In addition, we further analyzed the sensing mechanism of NiO materials to N2H4 gas through XPS and gas chromatography-mass spectrometry.

Ionic liquid-assisted electrodeposition synthesis of CuO films

CuO films were prepared by ionic liquid assisted electrodeposition to be used as photocatalysts to degrade organic dyes.

Ionic liquid-assisted synthesis of mesoporous polymers and carbon materials: the self-assembly mechanism.

Soft-templating synthesis has been widely employed to fabricate ordered mesoporous polymer and carbon materials with effectively tuneable pore sizes. However, the commonly used templating agents, block copolymers, are normally decomposed during the process, thus are barely recyclable; this increases the costs and hampers the scale-up feasibility. Therefore, it becomes imperative to seek promising alternatives; amphiphilic ionic liquids (ILs) are excellent candidates due to their good recyclability. This study explored the templating behaviour of IL templates for preparing mesoporous polymers and carbons. In details, the self-assembly of ternary systems (comprising of IL templates, precursors and solvent) were investigated by a combination of coarse-grained molecular dynamics (CGMD) simulations, density function theory (DFT) calculations and experimental techniques. The results indicate that the morphologies of IL templates are tuneable not only by the adjustment of water content in the mixture but also by the selection of suitable precursors. Material precursors containing increasing numbers of hydroxyl moieties also induce various precursor-template spatial correlations, resulting in different topological structures of nanomaterials. This work presents a fundamental investigation into the mechanisms of templating synthesis with amphiphilic ILs as recyclable templates and gives insight into the effective design of coveted carbon nanomaterials for targeted applications.

Synthetic Aspects of Condensed Pyrimidine Derivatives

The present review focuses on the synthesis of two heteroatoms containing sixmembered heterocyclic compounds, i.e., pyrimidine. In this review, a number of pyrimidine derivatives have been illustrated, which show the exceptional ability towards clinical practices. Pyrimidine derivatives show antimicrobial, antibacterial, antifungal, antiallergic, antiinflammatory, anticancer, and anticonvulsant activities. Therefore, researchers are encouraged to synthesize novel, potent, safe, and selective pyrimidine derivatives that are effective against the mutant strains, and the development of synthetic protocols is a high priority in medicinal chemistry research. Many methodologies have been developed for the preparation of pyrimidine derivatives. In this review article, the synthetic strategies of pyrimidine derivatives are classified into metal-catalyzed synthesis, ionic-liquid assisted synthesis, microwave-assisted synthesis, and solid-phase synthesis.

Nano-crystalline Nd3+-doped LuPO4 optical materials obtained by ionic liquid assisted synthesis route

LuPO4 in the form of nano-powders can find potential application in bio-imaging and luminescence thermometry. To enable development of functional materials there is a need to acquire basic information about the effect of morphology and grain size on spectroscopic properties. So, we investigated a series of Nd3+-doped LuPO4 nanoparticles prepared with task-specific ionic liquid as the reactant and in-situ stabilizer. Thus, fast and facile preparation of the desired well-crystallized single-phase phosphate nanomaterials was possible. The XRD patterns and TEM analysis revealed the influence of the synthesis conditions on the morphology and nanoparticles size, which is reflected in their spectroscopic properties. Low-temperature high-resolution techniques i.e. absorption spectroscopy at 4.2 K and laser site-selective spectroscopy at 77 K with Nd3+ ion as structural probe were used. Micro-powdered Nd3+-doped LuPO4 obtained by a solid-state reaction was applied as a reference. The possible application of this material as an optical thermometer was considered.

Ionic Liquid-Assisted Synthesis of Ag3PO4 Spheres for Boosting Photodegradation Activity under Visible Light

In this work, a simple chemical precipitation method was employed to prepare spherical-like Ag3PO4 material (IL-Ag3PO4) with exposed {111} facet in the presence of reactive ionic liquid 1-butyl-3-methylimidazole dihydrogen phosphate ([Omim]H2PO4). The crystal structure, microstructure, optical properties, and visible-light photocatalytic performance of as-prepared materials were studied in detail. The addition of ionic liquids played a crucial role in forming spherical-like morphology of IL-Ag3PO4 sample. Compared with traditional Ag3PO4 material, the intensity ratio of {222}/{200} facets in XRD pattern of IL-Ag3PO4 was significantly enhanced, indicating the main {111} facets exposed on the surface of IL-Ag3PO4 sample. The presence of exposed {111} facet was advantageous for facilitating the charge carrier transfer and separation. The light-harvesting capacity of IL-Ag3PO4 was larger than that of Ag3PO4. The photocatalytic activity of samples was evaluated by degrading rhodamine B (RhB) and p-chlorophenol (4-CP) under visible light. The photodegradation efficiencies of IL-Ag3PO4 were 1.94 and 2.45 times higher than that of Ag3PO4 for RhB and 4-CP removal, respectively, attributing to a synergy from the exposed {111} facet and enhanced photoabsorption. Based on active species capturing experiments, holes (h+), and superoxide radical (•O2−) were the main active species for visible-light-driven RhB photodegradation. This study will provide a promising prospect for designing and synthesizing ionic liquid-assisted photocatalysts with a high efficiency.

Enhanced photocatalytic performance of three-dimensional microstructure Bi2SiO5 by ionic liquid assisted hydrothermal synthesis

In this demonstration, Bi2SiO5 photocatalysts were prepared using ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate ([BMim]BF4) as a soft template. X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV–Vis diffuse reflectance spectroscopy (UV–Vis DRS), surface photovoltage spectroscopy (SPS), electron paramagnetic resonance (EPR), photoelectrochemical measurement and Raman were applied to investigate the structures, morphologies, optical and electronic properties. The results show that [BMim]BF4 affects the growth of IL-Bi2SiO5 grains and induces Bi2SiO5 to form thinner nanosheets. When the mass ratio of [BMim]BF4/Bi2SiO5 is 3%, Bi2SiO5 nanosheets begin to assemble into three-dimensional (3-D) flower-like structure. Rhodamine B (RhB) was employed to evaluate the photocatalytic performance of IL- Bi2SiO5. Under UV light irradiation, the degradation rate constant of RhB over the 3% sample is 5 times of that over the reference Bi2SiO5.

Ionic liquid-assisted synthesis of hierarchical Ti2Nb10O29 porous microspheres coated by ultrathin N-doped carbon layers for high-performance lithium-ion battery

Nanoparticle-assembled Ti2Nb10O29 porous microspheres coated by N-doped carbon layers (TNO@N–C-M) have been synthesized using ionic liquid 1-ethyl-3-methylimidazolium dicyanamide ([Emim]DCA) as carbon and nitrogen sources. Owing to the wide liquid range, low vapor pressure, and low surface tension of [Emim]DCA, the as-obtained N-doped carbon layers possess ultrathin thickness (~3 nm) and the primary TNO nanoparticles have ultrasmall sizes (20–30 nm). The synergistic effects from the particular structure lead to high electronic conductivity, fast ion/electron transport kinetics, and increscent pseudocapacitive contribution. Accordingly, the TNO@N–C-M anode has large discharge capacity (309.6, 262.2, 240.6, 216.5 and 204.5 mA h g−1 at 1, 5, 10, 20, and 30 C, respectively), good rate capacity (304.9 and 208.1 mA h g−1 at 1 and 30 C, respectively), and superior cycle stability (219.5 mA h g−1 after 500 cycles at 10 C). Also, the LiNi0.5Mn0.3Co0.2O2//TNO@N–C-M full cell also exhibits superior electrochemical properties with promising application prospect.

Ionic liquid-assisted synthesis of porous boron-doped graphitic carbon nitride for photocatalytic hydrogen production

This work presents a simple way to prepare boron-doped graphitic carbon nitride (B/g-C3N4), exhibiting an enhanced photocatalytic performance to split water for hydrogen production. B/g-C3N4 was synthesized via the pyrolysis of urea and 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim]BF4), which was adopted as the boron source. The aggregate of B/g-C3N4 nanosheets shows a porous structure since some bubbles are generated under the heat decomposition of ionic liquids. The porous structure is conducive to the exposure of more active sites. Moreover, B-doping will form some localized electronic energy levels in the band gap of g-C3N4, thereby extending its visible light response. As impacted by the porous structure of B/g-C3N4 aggregate and the narrow the band gap, the photocatalytic hydrogen generation rate (901 μmol h−1 g−1) is increased, almost 3 times faster than g-C3N4 (309 μmol h−1 g−1). This work proposed a simple method to prepare the aggregate of B/g-C3N4 nanosheets exhibiting pores under ionic liquid assistance. It can be a novel method to design porous polymer photocatalysts.

Ionic liquid-assisted synthesis of F-doped titanium dioxide nanomaterials with high surface area for multi-functional catalytic and photocatalytic applications

Ionic liquid (IL) assisted syntheses of ultrareactive F-doped mesoporous aggregates of titanium dioxide nanoparticles have been studied using different synthetic methods in order to obtain non-toxic, highly versatile systems able to combine the high photocatalytic activity of the F-doping with a high surface area, to be applied in different catalytic and photocatalytic processes of environmental interest. The synthesized materials were characterized by various techniques, showing that they consist of mesoporous aggregates of F-doped anatase nanoparticles with surface areas of up to ca. 200 m2/g, which, together with the incorporation of ultrareactive (001) anatase facets promoted by doping, made the synthesized titanium dioxide nanomaterials very active in photocatalytic processes. The studies systems showed in the photocatalytic degradation of organic contaminants degradations of up to 96 % of concentrated solutions of methylene blue and common emerging pollutants such as ciprofloxacin (90 % degradation) and naproxen (79 % degradation) under UV light (300 W) in 10 min. In addition, when doped with palladium nanoparticles they became effective heterogeneous catalysts in Suzuki–Miyaura C–C coupling reactions giving good to excellent halide conversions (between 60–99 % for the formation of biphenyl derivatives) and high TOF values (up to 120 h−1) at short reaction times and good degree of recyclability. In addition, the Pd- and Pt-doped systems were also tested in the green process of hydrogen production by methanol photoreforming, showing a good accumulated hydrogen amount of ca. 75 mmol after 400 min with moderate photonic efficiencies of up to ca. 4.1 %.

Ionic liquid assisted electrospinning synthesis for ultra-uniform Sn@ mesoporous carbon nanofibers as a flexible self-standing anode for lithium ion batteries

The long-cycle-life and high-capacity Sn@ Mesoporous Carbon Nanofibers (Sn@MCNFs-IL) self-standing anode was prepared by ionic liquid assisted electrospinning and pyrolysis strategy. Ionic liquid (AminCl) modifies the interface between the active particles and the electrospinning solutions, affecting electrospinning and pyrolysis process. The structure of ultra-uniform Sn encapsulated in porous carbon nanofibers resolves severe aggregation of Sn nanoparticles in carbon nanofibers, thus releasing stress form volume expansion of Sn and increasing storage lithium ions surface area of the Sn. The ultra-uniform Sn@MCNF-IL anode exhibited high capacity of 750 mA h g−1 at 0.5 A g−1 (comparing with Sn@CNF anode, improved 22%) with excellent Coulombic efficiency (89% at 1st cycle) and rate performance (300, 200 mA h g−1 at 4.0 and 10.0 A g−1). Remarkably, the cycling capability of the Sn@MCNF-IL anode (504 mA h g−1, 800 cycles at 0.5 A g−1) is superior to the cycling performance of Sn@CNF. The ionic liquid assisted strategy hopefully provides an advanced strategy in construction of excellent self-standing anode and the Sn@MCNFs-IL shows great promise as a candidate anode for superior performance flexible lithium-ion batteries.