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Supercapacitors (SCs) are fascinating energy storage devices due to their delivery of exceptional power density and long cycling stability. Unfortunately, their practical applications are still impeded by relatively inferior energy density, which is proportional to the square of the operating voltage of SCs. Ionic liquid (IL) electrolytes have a wide electrochemical stability window and thus can be used to significantly increase the energy density of SCs. The introduction of redox active species into IL‐based electrolytes effectively contributes to pseudocapacitance. Accordingly, IL‐based redox active electrolytes (IL‐REs) for SCs are springing up rapidly in recent years. This review provides an overall insight into various IL‐REs, including the ILs mixed with other redox active species, the ILs possessing redox active groups themselves, and the IL‐based redox gel polymer electrolytes for SCs. The basic understanding of IL electrolytes and IL‐REs is introduced and discussed as well as the application of the IL‐REs in SCs. Then, the energy storage mechanisms of these IL‐REs are discussed, and finally, current challenges and perspectives are highlighted for future research in this promising field. [ABSTRACT FROM AUTHOR]

Reasonable design of electrode materials to match ionic liquid electrolytes is important for the development of high-performance supercapacitors in the future. Herein, we demonstrate a nitrogen-doped agar-derived porous carbon (NAGC) electrode material with high specific capacitance and long cycling life, which was prepared using agar as precursor, potassium carbonate as activator, and melamine as nitrogen source via one-step activation doping method. The combined action of melamine and potassium carbonate can regulate and control the physical and electrochemical properties of the prepared materials. NAGC presents a high specific surface area (3228 m2/g) and micropores-dominated hierarchical porous structure, which can provide more adsorption sites and benefit rapid ions transport. The NAGC electrode in 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim][BF 4 ]) ionic liquid electrolyte has a specific capacitance of 183 F/g at 1 A/g and 91 % capacitance retention from 1 to 10 A/g. Additionally, the assembled device with NAGC as both positive and negative electrode material has a wide operating voltage (3.6 V) and high energy density of 70.2 Wh/kg at a power density of 1.81 kW/kg. Also, it possesses a capacitance retention of 83.3 % after 50,000 cycles. This work provides a simple and effective way to achieve porous carbon materials with high specific capacitance and long cycle life. [Display omitted] • Nitrogen-doped agar-derived porous carbon is synthesized via a simple method. • NAGC material has large specific surface area and suitable pore size distribution. • Pore size distribution of NAGC matches to the size of ionic liquid electrolytes. • The NAGC-2//NAGC-2 device has high energy density and ultra-long cycle life. [ABSTRACT FROM AUTHOR]

The abnormal concentration of lysozyme in body fluids and tissues is a potential indicator for diseases such as leukemia and meningitis. In this work, by combining the excellent optical properties of carbon dots (CDs) with the favorable selectivity of molecularly imprinted polymer (MIP), a novel fluorescent probe for lysozyme detection and cell imaging was constructed, where silanized CDs with low cytotoxicity (CDs/SiO2) were used as the fluorescence signal reporter and N-isopropylacrylamide (NIPAM) was used as the temperature-sensitive monomer. The as-prepared CDs/SiO2/MIP showed a thermo-sensitive property for the response to lysozyme. Moreover, this probe could be used for quantitative detection of lysozyme, with a wider detection range (0.001~0.01 mg/mL), a low detection limit (0.55 μg/mL), and a high selectivity. Importantly, the MTT assay testified that the fluorescent CDs/SiO2/MIP probe had low cytotoxicity. In addition, human hepatoma carcinoma cells (HepG-2 cells) could be stained by the CDs/SiO2/MIP, and showed a bright intracellular green fluorescence, indicating that the imaging of live cells was possible. This study provides a new way to detect lysozyme in vitro and an attractive perspective to probe intracellular lysozyme in vivo. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Liquid phase exfoliation (LPE) method has great potential for the large-scale production of graphene due to its simplicity, scalability, and low cost. In this work, fulvic acid (FA) was chosen to assist the exfoliation of graphite into graphene for the first time via sonication in aqueous medium. The concentration of obtained graphene dispersion can reach 0.63 ± 0.04 mg mL−1. The graphene flakes mostly consisted of 1–5 layers with sizes range in submicron to micron and few defects in the basal-plane. The π–π interaction between graphene and FA, along with the electrostatic repulsion between negatively charged FA, played a major role in stabilization of the graphene dispersion. By adjusting the pH of graphene dispersion to 14, the nanosheets of graphene came to flocculation. The formed graphene slurry is favorable for storage and transportation due to the greatly decreased volume. The annealed coating of FA-graphene on aluminum sheets was used as corrosion inhibitor for aluminum in 0.5 M H 2 SO 4 and 0.6 M NaCl solutions, with inhibition efficiencies of up to 85.5% and 99.4%, respectively. This shows that as-prepared graphene has great potential applications in the anti-corrosion of aluminum. [ABSTRACT FROM AUTHOR]

A facile and environment-friendly method was developed to synthesize sulfur- and nitrogen-co-doped carbon dots (S/N-CDs) via one step hydrothermal treatment of 1-butyl-3-methylimidazolium 2-amino-3-mercaptopropionic acid salt ionic liquid and polyethylene glycol. It was found that the prepared S/N-CDs were nearly spherical nanoparticles. And then the size of the as-prepared S/N-CDs became smaller with the extension of reaction time, the amorphous carbon was gradually transformed into a crystal structure of carbon dots and a higher reaction temperature favors the formation of carbon dots with higher quantum yields. It was also found that sulfur atoms in the S/N-CDs change the surface structures of CDs to some extent. Higher quantum yield of the S/N-CDs should attribute to the synergistic effect of co-doped nitrogen and sulfur atoms. The S/N-CDs display stable and strong florescence, high water solubility, excitation-dependent emission behavior, particularly the up-conversion photoluminescence performance. Furthermore, the as-prepared S/N-CDs were used as a sensitive probe for Hg 2+ detection in aqueous solutions, with high selectivity and sensitivity. Particularly, the detection limit could reach as low as 0.6 n M ( S / N =3). [ABSTRACT FROM AUTHOR]

[Display omitted] • Adsorption Gibbs energy can be calculated from the Langmuir adsorption coefficient for a pure component. • Adsorption Gibbs energy cannot be calculated for the plant extracts as a mixture inhibitor. • The relationship between Langmuir isotherm and adsorption Gibbs energy cannot be used for composite inhibitors. To explore the inhibition mechanism of corrosion inhibitors for metals in aqueous solution, the Langmuir adsorption isotherm has been widely used to ascertain the adsorption mode of the inhibitors on the metal surface. Meanwhile the obtained Langmuir adsorption coefficients have been further applied to calculate Gibb free energy change in the adsorption processes. However, the relationship between the Langmuir adsorption coefficients and Gibbs free energy change of adsorption has been misused for plant extracts (as inhibitors) whose composition and/or content were unknown. Herein, the relationship between the Langmuir adsorption coefficients and Gibbs free energy change is derived detailedly. And the applicable conditions of the relationship are analyzed and discussed for correct application and avoiding misuse. [ABSTRACT FROM AUTHOR]

Apparent molar volumes V Φ ,DIL and viscosity B -coefficients of the dicationic ionic liquids (DILs) in {glucose (Glc) + water} solutions were determined from density and viscosity measurements at T = 298.15 K. Limiting apparent molar volumes V Φ ,DIL 0 of the DILs, volumetric interaction parameters, and activation energies Δ μ DIL 0 ≠ were also obtained, together with the contributions of the solvent property B 1 and the dicationic ionic liquid – solvent interaction B 2 to the B -coefficient. A linear relation was observed between V Φ ,DIL 0 and the number of methylene groups n (CH 2 ) in the alkyl linkage chain of DILs. Volumetric interaction parameters and B 2 values are positive and increase with increasing the length of alkyl linkage chain of the dication. The DIL – glucose interactions were discussed in terms of the size and solvation of the DILs and glucose. [ABSTRACT FROM AUTHOR]

The conversion of cellulosic biomass directly into valuable chemicals becomes a hot subject. Six novel acidic ionic liquids (ILs) based on 2-phenyl-2-imidazoline were synthesized and characterized by UV–VIS, TGA, and NMR. The novel acidic ionic liquids were investigated as catalysts for the hydrolysis of cellulose in 1-butyl-3-methylimidazolium chloride ([Bmim]Cl). The acidic ionic liquids with anions HSO 4 − and Cl − showed better catalytic performance for the hydrolysis of cellulose than those with H 2 PO 4 − . The temperature and dosage of water affect significantly the yield of total reducing sugar (TRS). When the hydrolysis of cellulose was catalyzed by 1-propyl sulfonic acid-2-phenyl imidazoline hydrogensulfate (IL-1) and the dosage of water was 0.2 g, the TRS yield was up to 85.1% within 60 min at 100 °C. These new acidic ionic liquids catalysts are expected to have a wide application in the conversion of cellulose into valuable chemicals. [ABSTRACT FROM AUTHOR]

Activitycoefficients of the 1-alkyl-3-methylimidazolium bromide[Cnmim]Br (n= 3 to 8)ionic liquids (ILs) in fructose + water mixed solvents at 298.15 Kwere determined by cell potential measurements. The molalities of[Cnmim]Br ranged from (0.005 to 0.1) mol·kg–1and those of fructose from (0.2 to 0.8) mol·kg–1. Gibbs free energy interaction parameters were alsoobtained together with salt constants. The interactions between [Cnmim]Br and fructose are mainly controlledby electrostatic interactions. Gibbs free energy interaction parameters(gES) and salting constants (kS) are negative for the ILs (n= 3 to6), indicating fructose are salted-in by the ILs in water, whereasfructose are salted-out by the ILs (n= 7 and 8). [ABSTRACT FROM AUTHOR]

Abstract: Several alkylmethylimidazolium tetraphenylborates (C n mim-TPB, n =2–10) were synthesized and explored as ion exchangers in plasticized PVC membranes with very attractive sensing behaviors. And then a series of ion-selective electrodes (ISEs) were prepared and their potentiometric properties were investigated. The proposed electrodes exhibited Nernstian responses to alkylmethylimidazolium-based ionic liquid cations [C n mim]+. These electrodes were successfully applied in the determination of thermodynamic parameters of ionic liquids in aqueous solutions and in the detection of [C n mim]+ in tap water and distilled water with satisfactory results. For the as-prepared ISEs, one special and important relationship was observed between the selectivity coefficients and the length of alkyl side chains of interfering cations [C n mim]+. The proper understanding of this relationship should facilitate the development of new method for the determination of ionic liquids using ISEs. [Copyright &y& Elsevier]

Dilution enthalpies and mixing enthalpies of sodium halideandsome saccharides (glucose, galactose, xylose, arabinose, fructose,and sucrose) in aqueous solution were determined by calorimetric measurementsat 298.15 K. The values were used to determine enthalpic pair interactionparameters. Combined with Gibbs energy pair parameters, entropic pairinteraction parameters were also obtained. Theoretical calculationsat the B3LYP/6-311(d,p) level were carried out to provide the informationof structures and thermodynamic functions. The information revealsthe thermodynamic essence of the interactions between sodium halideand saccharides in aqueous solutions. The experimental results andtheoretical calculations show that the sign of enthalpic pair interactionparameter 2υhESis determined bythe direct interaction between saccharides and ions, whereas the differencein value of 2υhESfor differentsaccharides or electrolytes depends on the partial dehydration ofsaccharides or anions in aqueous solution. The difference in valueof entropic pair interaction parameters depends partly on the differentdominant interactions in the process of partial dehydration of saccharidesor ions. An enthalpy–entropy compensation relationship wasobserved for the sodium bromide–aldopyranose–water systems.Remarkably, it can be conjectured that the hydration entropy of glucoseis lower than for other monosaccharides. Perhaps it is one of thereasons why glucose plays an important role in living organisms ratherthan other monosaccharides. [ABSTRACT FROM AUTHOR]

Abstract: Viscosities and densities of d-glucose–water mixtures were measured, and conductivities in the NiSO4–d-glucose–water system were also measured at 278.15–308.15K in 5K intervals. Based on the Lee–Wheaton conductivity equation, values of limiting molar conductivities Λ 0 and association constants K A were obtained. Changes in the standard thermodynamic functions, Gibbs energy enthalpy and entropy for a process of ion-pair formation were calculated at different temperatures. The results show that (1) at given temperatures, the Λ 0 values for 1/2NiSO4 decrease with increasing concentrations of d-glucose; (2) at fixed concentrations of d-glucose, the Λ 0 values for 1/2NiSO4 increase with increasing temperature; and (3) the process of association of NiSO4 is controlled by the change in entropy . [Copyright &y& Elsevier]

Abstract: Densities have been measured for d-galactose+HCl+water at 10° intervals from 278.15 to 318.15 K. The apparent molar volumes (V Φ,Gal) and standard apparent molar volumes (V 0 Φ,Gal) for d-galactose in aqueous solutions of 0.2~2.1 mol kg−1 HCl have been calculated. Volumetric interaction parameters of galactose with HCl in water have also been obtained from transfer volumes. Results show that V Φ,Gal and V 0 Φ,Gal for galactose in aqueous HCl solutions increase with increasing molality of HCl. At a given temperature, the standard transfer apparent molar volumes (Δt V 0 Φ,Gal) for galactose from water to aqueous HCl solutions are positive and increase with increasing molality of HCl. In the investigated temperature range, the relation: V 0 Φ,Gal = b 0 + b 1(T −273.15 K)0.77 can be used to describe the temperature dependence of the standard apparent molar volumes. Values of standard partial molar isobaric expansion coefficient (∂V 0 Φ,Gal/∂T) p are positive and decrease with increasing temperature and molalities of HCl. [Copyright &y& Elsevier]

Abstract: A method for measuring individual ionic activity coefficients is proposed and used to obtain activity coefficients of the individual ions in aqueous solutions of NaF (about 0.02–0.99molkg−1), NaCl (about 0.01–1.10molkg−1) and NaBr (about 0.05–1.28molkg−1) at 298.15K. Values of these individual ionic activity coefficients are in agreement with the literature values. The mean ionic activity coefficients of NaF, NaCl and NaBr obtained from the activity coefficients of the individual ions are in good agreement with the literature values. In addition, dependences of the individual ionic activity coefficients upon molalities and properties of cations and anions are discussed. [Copyright &y& Elsevier]

Abstract: The 13C NMR spectra of methyl α- and β-d-galactopyranosides, and methyl α- and β-d-glucopyranosides were recorded and show that the Δ(δC-4) values for methyl α- and β-d-galactopyranosides increase most rapidly, whereas those for methyl α- and β-d-glucopyranosides vary hardly with increasing molality of calcium nitrate. It can be concluded that ax-OH-4 interacts more strongly with Ca2+ than eq-OH-4 group, namely, the Ca2+ ion interaction with ax-OH-4 leads to a stronger deshielding of the C-4 atom. Compared with other C atoms, the chemical shifts of both C-1 and C-5 atoms in these two types of glycosides decrease relatively rapidly as molality of calcium nitrate increases, indicating that the nitrate ion attractions for these glycosides cause a relatively strong enhancing shielding effect of C-1 and C-5 atoms. [Copyright &y& Elsevier]

When an electrode (negative/positive) with excellent capacity matches a counter electrode with relatively low capacity or a pair of excellent electrodes cannot match each other, overall performance of the constructed supercapacitors (SCs) will be limited. Here, we report a novel electrode material 1,5-diamino-4,8-dihydroxyanthraquinone (DHAQ) grafted nitrogen-doped graphene aerogel (DHAQ-NGA) prepared by simple hydrothermal method. Since DHAQ molecule contains –C(=O)− and −NH−/−OH groups, the DHAQ-NGA composite can act as both the negative and positive electrode materials for a supercapacitor in ionic liquid electrolyte to improve capacity by faradaic reactions on these two electrodes. In addition, the intramolecular hydrogen bonding of DHAQ can improve the stability of the material. Therefore, DHAQ-NGA displays an enhanced specific capacity of 410 C g−1 for the positive electrode and 454 C g−1 for the negative electrode material. The assembled device can deliver a high energy density of 117 Wh kg−1 at a power density of 822 W kg−1. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: The 13C NMR spectra of methyl β-d-glucopyranoside, methyl β-d-galactopyranoside, methyl β-d-xylopyranoside, and methyl β-l-arabinopyranoside were recorded in CaCl2/KCl+D2O mixtures and in D2O. The chemical shifts of C-1, C-3, and C-5 in the methyl β-d-glucopyranoside and methyl β-d-galactopyranoside decrease rapidly as molalities of CaCl2/KCl increase, while those of C-1, C-2, and C-3 in the methyl β-d-xylopyranoside and methyl β-l-arabinopyranoside decrease rapidly as molalities of CaCl2/KCl increase. Cations (Ca2+/K+) can weakly complex with O in OMe of the pyranosides studied. Results are discussed in terms of the stereochemistry of the pyranoside molecules and the structural properties of the ions. [Copyright &y& Elsevier]

Abstract: Activity coefficients of CaCl2 in disaccharide {(maltose, lactose)+water} mixtures at 298.15K were determined by cell potentials. The molalities of CaCl2 ranged from about 0.01mol·kg−1 to 0.20mol·kg−1, the mass fractions of maltose from 0.05 to 0.25, and those of lactose from 0.025 to 0.125. The cell potentials were analyzed by using the Debye–Hückel extended equation and the Pitzer equation. The activity coefficients obtained from the two theoretical models are in good agreement with each other. Gibbs free energy interaction parameters (g ES) and salting constants (k S) were also obtained. These were discussed in terms of the stereo-chemistry of saccharide molecules and the structural interaction model. [Copyright &y& Elsevier]

Abstract: Activity coefficients, Gibbs energy interaction parameters (g ES), salting constants (k S), limiting molar conductivities (Λ 0), and Walden products (Λ 0 η) for the calcium nitrate−monosaccharide (d-glucose and d-galactose)–water systems were determined from electrical potential and conductance measurements. Results show that both the g ES and Λ 0 η values for saccharide−calcium nitrate–water systems are in the order: d-glucose> d-galactose. This can be ascribed to the fact that the interactions of Ca2+ with d-galactose are stronger than those of the ions with d-glucose. d-Glucose is salted-out whereas d-galactose is salted-in by calcium nitrate in water, which results from the difference in stereo-structures of the saccharide molecules (axial hydroxyl, a-OH-4 and equatorial hydroxyl, e-OH-4). [Copyright &y& Elsevier]

• A novel N-Ti 3 C 2 T x /TiO 2 -RGO hybrid with cross-linked open structure is synthesized. • The EmimTFSI/ACN/LiTFSI electrolyte is formulated to match the electrode material. • The N-Ti 3 C 2 T x /TiO 2 -RGO possesses an enhanced specific capacitance of 188 F g−1. • The assembled supercapacitor device can deliver a high energy density of 46 Wh kg−1. Ti 3 C 2 T x , a typical MXene, bears tremendous attention as a type of potential electrode materials for supercapacitors. Regrettably, though Ti 3 C 2 T x electrode has excellent capacitance in aqueous electrolytes, it cannot achieve high energy density due to a narrow operating potential window of the aqueous electrolytes. Herein, we demonstrate a well-designed hybrid material: nitrogen-doped Ti 3 C 2 T x -reduced graphene oxide with in situ formed TiO 2 nanopaticles bridged by -NH- (N-Ti 3 C 2 T x /TiO 2 -RGO), and meanwhile formulate a ternary mixed electrolyte of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EmimTFSI), acetonitrile (ACN), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) to match the hybrid material. The N-Ti 3 C 2 T x /TiO 2 -RGO hybrid possesses a 3D cross-linked porous structure with rapid transport channels for the electrolyte ions. The formulated ionic liquid-based electrolyte has a wide electrochemical stability window and free lithium ions are able to conduct Faradaic redox reactions. Benefiting from its unique architectural structure, the N-Ti 3 C 2 T x /TiO 2 -RGO material delivers an enhanced specific capacitance (specific capacity) of 188 F g−1 (338 C g−1) at 1 A g−1 and exhibits a high rate capability. Furthermore, the assembled asymmetrical supercapacitor with the N-Ti 3 C 2 T x /TiO 2 -RGO-5 anode and the self-synthesized p -phenylenediamine functionalized reduced graphene oxide (PPD-RGO) cathode delivers a high energy density of 46 Wh kg−1 at a high-power density of 1550 W kg−1. This work develops a simple strategy to assemble 2D MXene sheets into 3D porous electrode materials compatible to the ionic liquid-based electrolyte for high performance supercapacitors. [Display omitted] [ABSTRACT FROM AUTHOR]

Correction for 'An azobenzene-modified redox-active ionic liquid electrolyte for supercapacitors' by Yuhua Zhao et al., Chem. Commun., 2022, https://doi.org/10.1039/d2cc04081f. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs), with their wide electrochemical stable potential window, are promising electrolytes for supercapacitors (SCs). The suitable matching of the ion size and shape of the ILs to the pore size and structure of porous carbon (PC) electrode materials can realize the enhanced capacitive performance of the SCs. Here we report an interesting result: The capacitance of PC-based SCs shows a quasi-sinusoidal relationship with the composition (mass fraction) of the binary IL mixture as the electrolyte. This relationship is also interpreted based on the matching between the pore sizes of the PC materials and the size/shape of various ions of the IL mixture electrolyte. This can provide a new strategy to improve the performance of SCs by formulating a suitable mixture of different ILs to match the carbon-based electrode materials with a special pore size distribution. [ABSTRACT FROM AUTHOR]

Superhydrophobic materials have been widely applied in rapid removal and collection of oils from oil/water mixtures for increasing damage to environment and human beings caused by oil-contaminated wastewater and oil spills. Herein, superhydrophobic materials were fabricated by a novel polypyrrole (PPy)/ZnO coating followed by hexadecyltrimethoxysilane (HDTMS) modification for versatile oil/water separation with high environmental and excellent reusability. The prepared superhydrophobic surfaces exhibited water contact angle (WCA) greater than 150° and SA less than 5°. The superhydrophobic fabric could be applied for separation of heavy oil or light oil/water mixtures and emulsions with the separation efficiencies above 98%. The coated fabric also realized highly efficient separation with harsh environmental solutions, such as acid, alkali, salt, and hot water. The superhydrophobic fabric still remained, even after 80 cycles of separation and 12 months of storage in air, proving excellent durability. These novel superhydrophobic materials have indicated great development potentials for oil/water separation in practical applications. [ABSTRACT FROM AUTHOR]

The simultaneous enhancement of energy density (E) and power density (P) is a highly pursued but difficult task in domain of supercapacitors, which necessitates good electrode/electrolyte compatibility, high electron/ion migration rates, and wide voltage window. Herein, an ionic liquid (IL) assisted hydrothermal reduction and modification tactics is employed to prepare 1-benzyl-3-methyl imidazolium cysteine ([Bzmim][Cys]) IL-modified reduced graphene oxide aerogel material (IL-rGA). The porous texture with suitable pore sizes and IL-modified surface of IL-rGA ensures rapid infiltration and sufficient adsorption of electrolyte ions, and therefore substantially enhances the specific capacitance. The symmetric IL-rGA supercapacitor using 1-ethyl-3-methyl tetrafluoroborate IL electrolyte delivers high E values of 104–33 W h kg−1 in the P range of 944–15,860 W kg−1, these output parameters can meet the requirements in more widespread electric facilities. The current work offers a promising way to enhance and balance the E and P values of carbonaceous supercapacitors via the surface modification of electrode materials and the matching with IL electrolytes. [Display omitted] • IL modified reduced graphene oxide aerogel was prepared by hydrothermal reaction. • The IL modification substantially enhanced the capacitance of rGA. • High energy and power densities were ensured by the symmetric supercapacito. [ABSTRACT FROM AUTHOR]

An electrochemical biosensor for the simultaneous determination of dopamine (DA) and uric acid (UA) in the presence of ascorbic acid (AA) was developed using a glassy carbon electrode modified with 1-butyl-3-methylimidazolium 2-amino-3-mercaptopropionic acid salt ionic liquid functionalized graphene (ILG/GCE). The ILG/GCE possessed excellent electrocatalytic activity toward the oxidation of AA, DA and UA. The separations of oxidation peak potentials of AADA, DAUA, and AAUA were 147, 145 and 292 mV, respectively. The electrochemical sensor showed excellent selectivity and stability and was applied successfully to the determination of DA and UA in real urine samples using the standard addition method with recoveries of 97.0-103.8 %. [ABSTRACT FROM AUTHOR]

Abstract: Activity coefficients for the (CaCl2 +amino acid+water) system were determined at a temperature of 298.15K using ion-selective electrodes. The range of molalities of CaCl2 is (0.01 to 0.20)mol·kg−1, and that of amino acids is (0.10 to 0.40)mol·kg−1. The activity coefficients obtained from the Debye–Hückel extended equation and the Pitzer equation are in good agreement with each other. Results show that the interactions between CaCl2 and amino acid are controlled mainly by the electrostatic interactions (attraction). Gibbs free energy interaction parameters (g EA) and salting constants (k S) are positive, indicating that these amino acids are salted out by CaCl2. These results are discussed based on group additivity model. [Copyright &y& Elsevier]

Apparent molar volumes (V[sub 2, f] ) and standard partial-molar volumes (V[sub 2] [sup 0] [sub , f] ) of LiClO[sub 4] and LiBr at 298.15 K have been determined from precise density measurements in solvent mixtures of propylene carbonate (PC) with dimethylformamide (DMF), tetrahydrofuran (THF), acetonitrile (AN), and methyl formate (MF). The scaled particle theory is used to calculate the contributions of the cavity formation and the electrolyte-solvent interactions to the standard partial-molar volumes. It is shown that V[sub 2] [sup 0] [sub , f] is strongly dependent on the nature of the solvents, and the trends in V[sub 2] [sup 0] [sub , f] with composition of the solvent mixtures are determined by the interaction volumes of electrolytes with solvents. The results are discussed in terms of ionic preferential solvation, packing effect of solvents in the solvation shell, and electrostriction of solvents by ion.Key words: partial-molar volume, scaled particle theory, lithium salts, propylene carbonate, solvent mixtures, lithium battery electrolytes.En se basant sur des mesures précises de densité dans des mélanges de solvants de carbonate de propylène (PC) avec du diméthylformamide (DMF), du tétrahydrofurane (THF), de l'acétonitrile (AN) et de formiate de méthyle (MF), on a déterminé les volumes molaires apparents (V[sub 2, f] ) et les volumes molaires partiels standards, (V[sub 2] [sup 0] [sub , f] ) du LiClO[sub 4] et du LiBr, à 298,15 K. On a utilisé la théorie de la particule pour calculer les contributions de la formation de la cavité et de l'interaction de l'électrolyte-solvant aux volumes molaires partiels standards. On a démontré que la valeur de V[sub 2] [sup 0] [sub , f] , dépend fortement de la nature des solvants et les tendances dans les valeurs de V[sub 2] [sup 0] [sub , f] avec la composition des mélanges de solvant sont déterminées ceux qui sont présents dans les volumes d'interaction des électrolytes avec les solvants. On discute des résultats sur la base de la solvatation ionique préférencielle, de l'effet du tassement des solvants dans la couche de solvatation et de l'électrostriction des solvants par l'ion.Mots clés : volume molaire partiel, théorie de la particule scalaire, sels de lithium, carbonate de propylène, mélanges de solvants, électrolytes de piles au lithium.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

[Display omitted] • Hierarchical porous MXene/TiO 2 -Fe-G aerogel is prepared via a hydrothermal strategy. • The EmimTFSI-ACN-LiTFSI electrolyte is formulated to match the electrode material. • MXene/TiO 2 -Fe-G exhibits enhanced specific capacitance and good rate capability. • Fabricated ASC achieves energy density of 54 Wh kg−1 at power density of 1737 W kg−1. To achieve pseudocapacitance by driving reversible redox reactions is scientifically appealing to realize high energy density of supercapacitors (SCs). In this work, a unique ferric ions-assisted self-assembly MXene/TiO 2 -graphene aerogel composite (MXene/TiO 2 -Fe-G) is developed. The MXene/TiO 2 -Fe-G composite has a 3D hierarchical porous framework, large accessible specific surface area, and amorphous TiO 2 modified on the surface of MXene nanosheets. Importantly, amorphous TiO 2 , generated from the partial oxidation of MXene, can contribute enormous pseudocapacitance via the reversible redox reaction with Lithium ions. In addition, ferric cations with variable valence states can also provide pseudocapacitance. A trinary ionic liquid-based electrolyte (1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide-acetonitrile-lithium bis(trifluoromethanesulfonyl)imide, EmimTFSI-ACN-LiTFSI) with a wide electrochemical stability potential window is also formulated to match the new material. Consequently, the MXene/TiO 2 -Fe-G composite as the negative electrode shows a superb specific capacitance of 196.4 F g−1 at 1 A g−1. An asymmetric supercapacitor assembled with the MXene/TiO 2 -Fe-G anode and self-synthesized nitrogen-doped reduced graphene oxide aerogel (N-RGA) cathode can deliver a high energy density of 54 Wh kg−1 at a high-power density of 1737 W kg−1. This work provides a possibility of implementing pseudocapacitance by changing the morphology and structure of MXene composites to match the ionic liquid-based electrolyte, which can considerably enhance the performance of MXene-based SCs. [ABSTRACT FROM AUTHOR]

The construction of potential electrode materials with wide temperature property for high‐energy‐density secondary batteries has attracted great interest in recent years. Herein, a hybrid electrode, consisting of a nitrogen‐doped carbon/α‐MnS/flake graphite composite (α‐MnS@N‐C/FG), is prepared through a post‐sulfurization route. In the α‐MnS@N‐C/FG composite, α‐MnS nanoparticles wrapped by the N−C layer are uniformly embedded onto FG, forming a novel nanofoam structure. The as‐obtained α‐MnS@N‐C/FG shows excellent lithium/sodium storage performance, with a specific capacity of 712 mA h g−1 in the 700th cycle at 1.0 A g−1 or 186.4 mA h g−1 in the 100th cycle at 100 mA g−1 using lithium or sodium foil as the counter electrode, respectively. Moreover, even operated at −20 °C, the α‐MnS@N‐C/FG can still attain a high specific capacity of 350 mA h g−1 after 50 cycles at 100mA g−1 for LIBs. This exceptional electrochemical response is attributed to the synergetic effect of the smart design of a hybrid nanofoam structure, in which the FG skeleton and N‐C coating layer can significantly enhance the conductivity of the whole electrode from bottom to top. Accordingly, the enhanced redox kinetics endow the electrode with pseudocapacitive‐dominated electrochemical behavior, leading to fast electrode reactions and robust structural stability in the whole electrode. [ABSTRACT FROM AUTHOR]

The main challenge in developing foldable Li–S batteries (LSB) lies in developing an electrode that is ultraflexible, conductive, and catalytic for dissolved lithium polysulfides (LiPSs). In this paper, lightweight macromolecule graphitic carbon nitride (g‐C3N4) film and a conductive polymer (CP) of poly(3,4‐ethylenedioxythiophene) shell are introduced into flexible LSBs by compositing with carbon cloth (CC). In the designed hybrid of CP/g‐C3N4@CC, 2D g‐C3N4 is used in the form of an effective trapper and functions as a continuous catalytic layer for LiPSs via the formation of pyridinic‐N‐Li bonds. This is revealed by both experimental investigations and theoretical analysis. The sandwich‐like CC and CP simultaneously bring an omnidirectional conductive network for fast interfacial reaction kinetics. With these benefits, the self‐supported CP/g‐C3N4@CC forms a powerful interaction system to fully in situ "lock" LiPSs in the commercial CC matrix. Thus, a substantially enhanced electrochemical performance is obtained at a high sulfur loading (4.7 mg cm–2) even operating in a pouch cell. This work may provide a potential avenue for practical use of high‐performance LSBs toward flexible energy‐storage devices. [ABSTRACT FROM AUTHOR]

Using the surface molecular imprinting technique, a thermo-sensitive molecularly imprinted fluorescent sensor was constructed for bovine hemoglobin (BHb) detection with the silanized carbon dots (CD@SiO2) as fluorescent signal, N-isopropylacrylamide as monomer sensitive to temperature, and BHb as template. The silanized carbon dots coated by the molecularly imprinted polymer (CD@SiO2@MIP) were characterized by high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, and fluorescence spectroscopy. Owing to the combination of the strong fluorescence sensitivity of CDs and the high selectivity of the molecular imprinting shell, the prepared sensor showed good recognition and detection performance to the target protein BHb, with a linear range of 0.31–1.55 μM and a detection limit of 1.55 μM. Furthermore, the sensor was utilized to detect the content of BHb in real urine with a recovery of 98.6–100.5%. The CD@SiO2@MIP sensors present a high potential for applications in the detection of BHb in biological systems. [ABSTRACT FROM AUTHOR]

A facile approach was developed to prepare well-dispersed ionic liquid functionalized graphene composites using 1-butyl-3-methylimidazolium 2-amino-3-mercaptopropionic acid salt ionic liquid as a reducing reagent and functionalization reagent. The resulting material showed excellent electrochemical activity to catechol and hydroquinone. [ABSTRACT FROM AUTHOR]

Aromatic bromination of heteroarenes has been accomplished by using readily available LiBr with the aid of BF3⋅Et2O under mild aerobic conditions. The broad substrates scope of the reaction is compatible with the optimized condition, and excellent functional‐group is well tolerated in this transformation. The gram‐scale preparation of aromatic bromide exhibits with good reaction efficiency. Meanwhile, the dibromination of heteroarene delivers the polybromo‐aromatic compounds in good yields. [ABSTRACT FROM AUTHOR]

In this work, we prepared reduced graphene oxide-supported PtCo nanospheres (PtCo/rGO) by a facile one-step hydrothermal method with the assistance of L-proline as the shape-directing agent. We systematically investigated the effects of various experimental conditions on the morphology and structure of the as-prepared PtCo/rGO hybrids. Compared with commercial Pt/C (10 wt%) and Pt/rGO catalysts, the as-prepared PtCo/rGO has better catalytic activity and poisoning resistance toward methanol electrooxidation and can be used as a promising catalyst for direct methanol fuel cells.Graphical abstract: The rGO-supported PtCo nanosphere hybrids are successfully synthesized by a facile one-pot hydrothermal method with the assistance of L-proline. L-proline acts as shape-controlled agent for synthesizing PtCo/rGO. The as-prepared PtCo/rGO hybrids exhibit a higher electrocatalytic activity and poisoning-resistant ability for methanol oxidation in acidic media. [ABSTRACT FROM AUTHOR]

A hybrid shell material of hollow Nb2O5 microspheres has been engineered as an effective sulfur host for use in Li–S batteries. Of particular note is that the selected Nb2O5 not only exhibits ultrafast Li+ motion properties due to its unique room-and-pillar NbO6/NbO7 framework structure, but also demonstrates moderate polar affinities to the lithium polysulfides based on theoretical calculations. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Densities and viscosities of glycine in aqueous solutions of ILs ([C 2 mim]Br, [C 4 mim]Br, [C 6 mim]Br) were measured. • Values of V Φ 0 and Δ t V Φ 0 increase with increasing IL concentrations and follow the order: [C 2 mim]Br > [C 4 mim]Br > [C 6 mim]Br. • The B -coefficients at given molalities of the ILs are in the order: [C 2 mim]Br < [C 6 mim]Br < [C 4 mim]Br. • These phenomena were explained by means of the structural hydration interaction model. Abstract Densities and viscosities for the glycine + 1-alkyl-3-methylimidazolium bromide ([C n mim]Br, n = 2, 4, 6) ionic liquids (ILs) + water systems were measured at 298.15 K. Meanwhile, the apparent molar volumes, V Φ , infinite dilution apparent molar volumes, V Φ 0 , standard volumes of transfer, Δ t V Φ 0 , of glycine and volumetric interaction parameters were further calculated. The viscosity B -coefficients of glycine in the aqueous IL solutions were calculated by using the Jones-Dole equation. The results show that both V Φ 0 and Δ t V Φ 0 values for glycine are positive and increase with increasing IL concentrations and follow the order: [C 2 mim]Br > [C 4 mim]Br > [C 6 mim]Br. However, the B -coefficients at given molalities of the ILs are in the order: [C 2 mim]Br < [C 6 mim]Br < [C 4 mim]Br. These phenomena are discussed and interpreted by means of the structural hydration interaction model and aggregation behavior of the [C 6 mim]Br in water. This work provides the important basic data for the understanding of the interaction between the ILs and amino acids/proteins and for the design of industrial processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ethyl viologen functionalized reduced graphene oxide (EV-RGO) composite is prepared. • EV-RGO as the electrode material displays a well match with ionic liquid electrolyte. • EV-RGO can contribute both double electric layer capacitance and pseudocapacitance. • EV-RGO shows excellent specific capacitance and rate capability. • An asymmetric EV-RGO//AC device delivers an excellent energy density of 64.1 Wh kg−1. The development of pseudocapacitive materials matching ionic liquid (IL) electrolytes can significantly enhance the performance of supercapacitors (SCs). Herein we report an ethyl viologen-functionalized reduced graphene oxide composite (EV-RGO) synthesized by one-step hydrothermal method. In EV-RGO, the ethyl viologen cations are anchored on the RGO sheets through electrostatic interactions, π - π stacking interactions, and cation- π interactions, which makes EV-RGO as an electrode material more stable and reversible during charging and discharging. Meanwhile, the viologen cations with ethyl groups can better function as a spacer to suppress effectively the stacking of RGO sheets and expand their interlayer spacing. In 1-ethyl-3-methylimidazolium tetrafluoroborate (EmimBF 4) IL electrolyte, the electrochemical performance of the composite is enhanced due to synergic contributions from electric double-layer capacitance and pseudocapacitance. The pseudocapacitance mechanism is also supported by the results of XPS data. The specific capacitance of the EV-RGO as a negative electrode material for SCs reaches to 222.7 F g−1 at a current density of 0.5 A g−1. An asymmetric SC device (EV-RGO//AC ASC) exhibits an energy density of 64.1 Wh kg−1 at a power density of 888 W kg−1. This work offers an advanced strategy for the fabrication of high-performance SCs using organic molecule-modified graphene composites. [ABSTRACT FROM AUTHOR]

Abstract: A practical protocol is developed using carbon dioxide as a promoter for the C=N bond cleavage of amidines. This direct and operationally simple approach afforded parallel library of multi‐functional pyridines under the mild condition. The mechanistic isotope labeling experiment suggested that the oxygen atom of resulting carbonyl group was originated from water. [ABSTRACT FROM AUTHOR]

Nitrogen and sulfur co-doped graphene aerogel (NS-GA) is prepared by one-pot process. The as-prepared materials are investigated as supercapacitors electrodes in an ionic liquid (1-ethyl-3-methylimidazolium tetrafluoroborate, EMIMBF 4 ) electrolyte. The NS-GA is characterized using X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy scanning electron microscopy. The results show that the NS-GA has hierarchical porous structure. Electrochemical performance is investigated by cycle voltammetry and galvanostatic charge-discharge. Notably, the supercapacitor based on the NS-GA-5 possesses a maximum energy density of 100.7 Wh kg −1 at power density of 0.94 kW kg −1 . The electrode materials also offer a large specific capacitance of 203.2 F g −1 at a current density of 1 A g −1 and the capacitance retention of NS-GA-5 is 90% after 3000 cycles at a scan rate of 2 A g −1 . The NS-GA-5 with numerous advantages including low cost and remarkable electrochemical behaviors can be a promising electrode material for the application of supercapacitors. [ABSTRACT FROM AUTHOR]

Abstract Aqueous two-phase systems (ATPSs) are of great significance for the extraction of drugs and biomolecules. In this work, we constructed two-ionic liquid (IL)-based quaternary ATPSs (IL Pri + IL Adj + K 2 HPO 4) for extracting pyritinol hydrochloride (PHC), where IL Pri (primary IL) was used to form the ATPSs, and IL Adj (adjuvant IL) was used to improve performance of the ATPSs. Using the two-IL-based ATPSs, the extraction efficiency (E) of PHC can reach up to ~100% when only a very small amount of ILs is used. The results of conductivity and dynamic light scattering (DLS) indicate that the simultaneous application of two ILs increases the effective specific surface area of the IL aggregates, then enhances the interaction between PHC and IL aggregates, and thus improves the E of the PHC. The multi-site cooperative-interactions between PHC and IL aggregates are the dominant driving force for the transfer of PHC to the IL-rich top phase and are the main reason for the improvement of E. This study provides a way to construct various quaternary ATPSs with specific functions for efficiently extracting and separating drugs and biomolecules. Graphical abstract Image 2 Highlights • Two-ionic liquid (IL)-based aqueous two-phase systems (ATPSs) were constructed. • Extraction efficiency (E) of pyritinol hydrochloride (PHC) reaches ~100% with ATPSs. • The simultaneous application of two ILs enhances performances of IL-based ATPSs. • Multi-site cooperative-interactions between PHC and IL aggregates improve E. [ABSTRACT FROM AUTHOR]

Trifluoromethanesulfonic acid catalyzed C--O bond cleavage leading to the preparation of functional esters in the presence of N-methylpyrrolidin-2-one (NMP) was accomplished. Various substrates were well tolerated, and a gram-scale experiment was successfully realized. DFT calculations indicated that NMP plays a decisive role in accelerating nucleophilic attack of the functional acid to generate the functional esters in chlorobenzene. [ABSTRACT FROM AUTHOR]

CdTe quantum dots (QDs) capped by 1-ethyl-3-methylimidazolium mercaptopropionate ([emim]MP) and the reduced graphene oxide (RG) modified by the amine-terminated ionic liquid ([amim]Br) were synthesized in this work. The coordinating interface interactions between QD and RG render the nanocomposite the excellent electrochemical performances as revealed by cyclic voltammetry, chronocoulometry, and electrical impedance spectroscopy. Based on the experimental results obtained from amimRG, CdTe@MP-amimRG, CdTe@[bmim]MP-amimRG, and CdTe@[emim]MP-amimRG nanocomposites, it is proposed that the synergistic effects between imidazolium rings and graphene are responsible for the enhanced performances. Taking the CdTe@[emim]MP-amimRG nanocomposite as the electrochemical sensor of puerarin, the proposed method demonstrates the linear range over 0.01–4.0 μmol L −1 with the detection limits of 6 nmol L −1 in the aqueous solution (S/N = 3). Moreover, the sensor exhibits fast response time (2s), high sensitivity (74.57 μA μmol L −1 cm −2 ), as well as reproducibility (RSD ≤ 8%), and can maintain the stability at 4 °C for two weeks. [ABSTRACT FROM AUTHOR]

Polyheterocycle construction with high diastereoselectivity by utilizing a radical process is still problematic. In this communication, a silver-catalyzed carbon-phosphorus functionalization for polyheterocycle formation is described that furnishes good diastereoselectivity. Various substituted 1-(1 H-indol-1-yl)-3-phenylprop-2-en-1-ones and phosphine oxides were suitable for this transformation. This work avoids the installation of direct functional groups and thus makes full use of shorter and more efficient synthetic processes. Preliminary mechanistic investigations indicate that phosphorus radicals are involved by attacking the α-position of α,β-unsaturated carbonyl compounds to generate the desired products. [ABSTRACT FROM AUTHOR]

The synthesis of chromeno[2,3-b]indole from simple starting materials remains a demanding process. Herein, 2-bromoindole undergoes nucleophilic attack from salicylaldehyde, followed by intramolecular insertion of an aldehyde group and aromatization to generate the desired chromeno[2,3- b]indoles. Moreover, various functional groups were tolerated and a gram-scale synthesis of the product could be achieved under the optimized condition. [ABSTRACT FROM AUTHOR]

The aerobic oxidative annulation of chalcones, pyridines/isoquinoline and ethyl chloroacetate to indolizines was achieved by cascade reaction. Various functional groups on chalcones were tolerated. And different pyridines derivatives could also be suitable substrates. Ethyl chloroacetate is an essential component in participating of the oxidative annulation process. Overall, this protocol is very practical and efficient by using molecular oxygen as oxidant with high selectivity for the annulation product. [ABSTRACT FROM AUTHOR]

With the intensive research of ionic liquids, more and more shortcomings of ionic liquids have been gradually found. At the same time, more ionic liquids with specific or multifunctional properties need to be designed for their wide applications. Thereby, the research for seeking new families of functionalized ionic liquids has been a hot topic. In this paper, we firstly synthetized seven novel functionalized gluconate-based ionic liquids [C n mim][C 6 H 11 O 7 ] (GBILs, n = 2, 4, 6, 8, 10, 12, and 14). Meanwhile, the volumetric, viscosity and conductivity properties for the GBIL + solvent (water/ethanol/propyl alcohol) systems were studied. The interactions between the ionic liquids and solvents were also explored. The results indicated that the interactions between the studied ILs and solvent depend on the structures of GBILs and the category of solvents. [ABSTRACT FROM AUTHOR]

The thermodynamics of molecular self-assembling of an anionic biosurfactant, sodium cholate (NaCA) and its mixtures with sodium dodecyl sulfate (SDS) in aqueous solution have been investigated by isothermal titration calorimetry (ITC), along with fluorescence and conductivity measurements. Different critical concentrations were obtained by these three techniques – critical pre-micelle concentration (cmc pre ) and critical micelle concentration (cmc) for pure NaCA, and critical micelle concentrations (cmc mix ) for the mixed systems with differently initial SDS concentrations. Importantly, ITC allowed us to directly measure the enthalpy changes of pre-micelle formation (Δ H premic = (−0.28 ± 0.02) kJ·mol −1 ) and of micelle formation (Δ H mic = (−1.76 ± 0.05) kJ·mol −1 ) for pure NaCA as well as the enthalpies for micellization for the mixed systems NaCA/SDS. The non-ideality of the mixed surfactant solution was evaluated in terms of interaction parameters and excess enthalpies that were calculated in the light of Clint’s and Rubingh’s models. It was found that there is an obvious synergistic effect in the NaCA/SDS mixed system. From all these results we can ascribe the strong interaction between the same charge surfactants NaCA and SDS to the structural difference in their hydrophobic moieties. In fact, the flexible alkyl chains of SDS and the non-planar hydrophobic β -faces of NaCA tend to have a more compact packing than pure NaCA. [ABSTRACT FROM AUTHOR]

The thermodynamics and phase behavior of mixtures of cationic gemini surfactant decanediyl-α,ω-bis(dodecyldimethylammonium bromide) (12-10-12) and sodium dodecylsulfate (SDS) were studied in the dilute SDS-rich region. The enthalpy of interaction between both surfactant monomers before the critical micelle concentration for the mixture (cmc mix ) was determined by isothermal titration calorimetry (ITC). After the cmc mix , ITC results exhibited a first process associated with a large endothermic enthalpy change followed by a second one with a very small exothermic enthalpy change. In the same regions, the conductivity curves show an increase in slope after the break, followed by a plateau region, respectively for the two processes. The combined results from the various methodologies used lead us to propose that the first process reflects the formation of non-spherical micelles and the second one the vesicle formation. The area per catanionic complex was obtained through surface pressure measurements, leading to an apparent packing parameter ⩾1. The observed behavior may be rationalized on the basis of the hypothesis that both surfactants distribute asymmetrically in the vesicle bilayers and unevenly in the non-spherical micelle. In order to get structural information Cryo-TEM experiments were performed, which provided images that support this interpretation. From all the information gathered a phase diagram was mapped, including three one-phase regions of spherical micelles, non-spherical micelles and vesicles. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) as versatile carbon-based nanomaterials have attracted increasing attention because of their non-toxicity, good water solubility and photostability, and easy surface functionalization. For their wide application, it is still needed to explore moderate and facile methods for synthesizing CDs from green and inexpensive precursors. In this paper, a moderate method was developed to synthesize water-soluble CDs by ionothermal treatment of cellulose with SOH-functionalized acidic ionic liquid as a catalyst in 1-butyl-3-methylimidazolium chloride ([Bmim]Cl). The preparation process was carried out at relatively low temperature in non-pressurized vessel. The synthesized CDs exhibit near-spherical morphology with an average diameter of 8.0 nm, and the surface is carbon and oxygen rich. The CDs have powder-blue fluorescence with excitation-dependent emission behavior and excellent stability. Moreover, the as-prepared CDs were demonstrated as an effective 'turn-off' fluorescent probe for the selective detection of Hg with a good linear relationship over the concentration range from 6 to 80 μM. The application of acidic ionic liquid should provide a new path for the synthesis of CDs under mild condition. [ABSTRACT FROM AUTHOR]