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In this work, we determine the dissociation line of the nitrogen (N2) hydrate by computer simulation using the TIP4P/Ice model for water and the TraPPE force field for N2. This work is the natural extension of Paper I, in which the dissociation temperature of the N2 hydrate has been obtained at 500, 1000, and 1500 bar [Algaba et al., J. Chem. Phys. 159, 224707 (2023)] using the solubility method and assuming single occupancy. We extend our previous study and determine the dissociation temperature of the N2 hydrate at different pressures, from 500 to 4500 bar, taking into account the single and double occupancy of the N2 molecules in the hydrate structure. We calculate the solubility of N2 in the aqueous solution as a function of temperature when it is in contact with a N2-rich liquid phase and when in contact with the hydrate phase with single and double occupancy via planar interfaces. Both curves intersect at a certain temperature that determines the dissociation temperature at a given pressure. We observe a negligible effect of occupancy on the dissociation temperature. Our findings are in very good agreement with the experimental data taken from the literature. We have also obtained the driving force for the nucleation of the hydrate as a function of temperature and occupancy at several pressures. As in the case of the dissociation line, the effect of occupancy on the driving force for nucleation is negligible. To the best of our knowledge, this is the first time that the effect of the occupancy on the driving force for nucleation of a hydrate that exhibits sII crystallographic structure is studied from computer simulation. [ABSTRACT FROM AUTHOR]

8-oxo-7,8-dihydro-2′-dexyoguanine (8-oxo-dG) can be tautomerized to a 6-enolate,8-keto tautomer through nearby-NH deprotonation at elevated pH. In this work, the N3-protonated 8-oxo-dG tautomers in deuterated pH-buffer solutions were studied using steady-state UV/Vis, FTIR, and ultrafast two-dimensional IR spectroscopies. The presence of 6,8-diketo and C6-anionic tautomers at neutral to basic conditions (pD = 7.4–12.0) was revealed by UV/Vis and FTIR results and was further confirmed by 2D IR signals in both diagonal and off-diagonal regions. However, the C6-enol tautomer, which may be an intermediate during the transition from 6,8-diketo to C6-enolate,C8-keto, was not observed appreciably due to its extreme low population. Furthermore, the neutral-to-anionic tautomeric transition of N3H-8-oxo-dG studied in this work occurs under more basic conditions than the N1H-8-oxo-dG reported previously, showing a higher pKa value for N3H than N1H. Finally, vibrational relaxation of the carbonyl stretching mode was found to be both molecular site dependent and pD dependent for 8oxo-dG. Taken together, this work shows that the ultrafast infrared spectroscopic method is effective for examining tautomers and their dynamics in nucleic acids. [ABSTRACT FROM AUTHOR]

This paper presents the first implementation of a coupling between advanced wavefunction theories and molecular density functional theory (MDFT). This method enables the modeling of solvent effect into quantum mechanical (QM) calculations by incorporating an electrostatic potential generated by solvent charges into the electronic Hamiltonian. Solvent charges are deduced from the spatially and angularly dependent solvent particle density. Such a density is obtained through the minimization of the functional associated with the molecular mechanics (MM) Hamiltonian describing the interaction between the fluid particles. The introduced QM/MDFT framework belongs to QM/MM family of methods, but its originality lies in the use of MDFT as the MM solver, offering two main advantages. First, its functional formulation makes it competitive with respect to sampling-based molecular mechanics. Second, it preserves a molecular-level description lost in macroscopic continuum approaches. The excited state properties of water and formaldehyde molecules solvated into water have been computed at the selected configuration interaction (SCI) level. The excitation energies and dipole moments have been compared with experimental data and previous theoretical work. A key finding is that using the Hartree–Fock method to describe the solute allows for predicting the solvent charge around the ground state with sufficient precision for the subsequent SCI calculations of excited states. This significantly reduces the computational cost of the described procedure, paving the way for the study of more complex molecules. [ABSTRACT FROM AUTHOR]

Here, we report the frequency-dependent spectrum of ice Ih in the range of 0.2–2 THz. We confirm the presence of a feature that blue-shifts from around 1.55–1.65 THz with a decreasing temperature from 260 to 160 K. There is also a change in the trend of the refractive index of ice corresponding to a dispersion, which is also around 1.6 THz. The features are reproduced in data acquired with three commercial terahertz time-domain spectrometers. Computer-simulated spectra assign the feature to lattice translations perpendicular to the 110 and 1 ̄ 10 planes of the ice Ih crystal. The feature's existence should be recognized in the terahertz measurements of frozen aqueous solution samples to avoid false interpretations. [ABSTRACT FROM AUTHOR]

In this work, the effects of finite size on the determination of the three-phase coexistence temperature (T3) of the carbon dioxide (CO2) hydrate have been studied by molecular dynamic simulations and using the direct coexistence technique. According to this technique, the three phases involved (hydrate–aqueous solution–liquid CO2) are placed together in the same simulation box. By varying the number of molecules of each phase, it is possible to analyze the effect of simulation size and stoichiometry on the T3 determination. In this work, we have determined the T3 value at 8 different pressures (from 100 to 6000 bar) and using 6 different simulation boxes with different numbers of molecules and sizes. In two of these configurations, the ratio of the number of water and CO2 molecules in the aqueous solution and the liquid CO2 phase is the same as in the hydrate (stoichiometric configuration). In both stoichiometric configurations, the formation of a liquid drop of CO2 in the aqueous phase is observed. This drop, which has a cylindrical geometry, increases the amount of CO2 available in the aqueous solution and can in some cases lead to the crystallization of the hydrate at temperatures above T3, overestimating the T3 value obtained from direct coexistence simulations. The simulation results obtained for the CO2 hydrate confirm the sensitivity of T3 depending on the size and composition of the system, explaining the discrepancies observed in the original work by Míguez et al. [J. Chem Phys. 142, 124505 (2015)]. Non-stoichiometric configurations with larger unit cells show a convergence of T3 values, suggesting that finite-size effects for these system sizes, regardless of drop formation, can be safely neglected. The results obtained in this work highlight that the choice of a correct initial configuration is essential to accurately estimate the three-phase coexistence temperature of hydrates by direct coexistence simulations. [ABSTRACT FROM AUTHOR]

We determine the surface tension of aqueous electrolyte solutions in contact with non-polar dielectric media using a thermomechanical approach, which involves deriving the stress tensor from the thermodynamic potential of an inhomogeneous fluid. To obtain the surface tension, we calculate both the normal and tangential pressures using the components of the stress tensor, recently derived by us [Y. A. Budkov and P. E. Brandyshev, J. Chem. Phys. 159, 174103 (2023)] within the framework of Wang's variational field theory. Using this approach, we derive an analytical expression for the surface tension in the linear approximation. At low ionic concentrations, this expression represents the classical Onsager–Samaras limiting law. By utilizing only one fitting parameter, which is related to the affinity of anions to the dielectric boundary, we successfully approximated experimental data on the surface tension of several aqueous electrolyte solutions. This approximation applies to both the solution–air and solution–dodecane interfaces, covering a wide range of electrolyte concentrations. [ABSTRACT FROM AUTHOR]

Developing highly efficient methane (CH4) hydrate storage methods and understanding the hydrate dissociation kinetics can contribute to advancing CH4 gas storage and transport. The effects of tetrabutylammonium bromide (TBAB) (a thermodynamic promoter) addition on the kinetics of CH4 hydrate were evaluated on the microscopic scale using synchrotron x-ray computed tomography (CT) and powder x-ray diffraction. Microscopic observations showed that a 5 wt. % TBAB solution facilitated the nucleation of CH4 hydrate owing to the initial growth of TBAB semi-clathrate hydrate particles. The CH4 hydrate crystals in the CH4 + TBAB hydrate sample were sponge-like with many internal pores and exhibited slightly enhanced self-preservation compared to the pure CH4 hydrate, both in the bulk and after pulverization to a fine powder. This study demonstrates the feasibility of controlling the rate of CH4 hydrate formation and preservation by using aqueous TBAB solutions in CH4 hydrate formation. [ABSTRACT FROM AUTHOR]

Semiconductor nanocrystals (NCs) can function as efficient gain materials with chemical versatility because of their surface ligands. Because the properties of NCs in solution are sensitive to ligand–environment interactions, local chemical changes can result in changes in the optical response. However, amplification of the optical response is technically challenging because of colloidal instability at NC concentrations needed for sufficient gain to overcome losses. This paper demonstrates liquid lasing from plasmonic lattice cavities integrated with ligand-engineered CdZnS/ZnS NCs dispersed in toluene and water. By taking advantage of calcium ion-induced aggregation of NCs in aqueous solutions, we show how lasing threshold can be used as a transduction signal for ion detection. Our work highlights how NC solutions and plasmonic lattices with open cavity architectures can serve as a biosensing platform for lab-on-chip devices. [ABSTRACT FROM AUTHOR]

The nucleation of ice from aqueous solutions is a process essential to myriad environmental and industrial processes, but the physical factors affecting the capacity of different solutes to depress the homogeneous nucleation temperature of ice are yet poorly understood. In this work, we demonstrate that for many binary aqueous solutions of non-ionic solutes, this depression is dominated by the entropy of the liquid phase. Employing the classic Turnbull interpretation of the interfacial free energy γ ∼ T S l i q u i d − S s o l i d and estimating solution entropies with a Flory-style modification of the ideal entropy of mixing that accounts for solute size effects, we demonstrate that mixing entropy alone predicts experimental homogeneous nucleation temperatures across a wide variety of non-ionic solutions. We anticipate that this physical insight will not only enhance a fundamental understanding of homogeneous nucleation processes across fields but also open new avenues to the rational design of aqueous solutions for desired nucleation behaviors. [ABSTRACT FROM AUTHOR]

Experimental and theoretical advances for understanding the temperature of maximum density (TMD) of aqueous solutions are outlined. The main equations that relate the TMD behavior to key thermodynamic properties are stated. The experimental TMD data are classified as a function of the nature of the solute (inorganic electrolytes, non-electrolytes, organic salts and ionic liquids, and amino acids and proteins). In addition, the experimental results that explore the effect of pressure are detailed. These experimental data are rationalized by making use of qualitative and semi-quantitative arguments based on the thermodynamics of aqueous systems. The main theoretical and simulation advances in TMD for aqueous solutions are also shown—including new calculations in the context of the scaled particle theory—and their ability to reproduce the experimental data is evaluated. Finally, new experiments and theoretical and simulation developments, which could give important insights into the problem of TMD for aqueous solutions, are proposed. [ABSTRACT FROM AUTHOR]

In this work, we determine the dissociation line of the nitrogen (N2) hydrate by computer simulation using the TIP4P/Ice model for water and the TraPPE force field for N2. We use the solubility method proposed recently by some of us to evaluate the dissociation temperature of the hydrate at different pressures, from 500 to 1500 bar. Particularly, we calculate the solubility of N2 in the aqueous solution when it is in contact with a N2-rich liquid phase and when in contact with the hydrate phase via planar interfaces as functions of temperature. Since the solubility of N2 decreases with temperature in the first case and increases with temperature in the second case, both curves intersect at a certain temperature that determines the dissociation temperature at a given pressure. We find a good agreement between the predictions obtained in this work and the experimental data taken from the literature in the range of pressures considered in this work. From our knowledge of the solubility curves of N2 in the aqueous solution, we also determine the driving force for nucleation of the hydrate, as a function of temperature, at different pressures. In particular, we use two different thermodynamic routes to evaluate the change in chemical potential for hydrate formation. Although the driving force for nucleation slightly decreases (in absolute value) when the pressure is increased, our results indicate that the effect of pressure can be considered negligible in the range of pressures studied in this work. To the best of our knowledge, this is the first time the driving force for nucleation of a hydrate that exhibits crystallographic structure sII, along its dissociation line, is studied from computer simulation. [ABSTRACT FROM AUTHOR]

Concentrated ionic aqueous electrolytes possess a diverse array of applications across various fields, particularly in the field of energy storage. Despite extensive examination, the intricate relationships and numerous physical mechanisms underpinning diverse phenomena remain incompletely understood. Molecular dynamics simulations are employed to probe the attributes of aqueous solutions containing LiCl, NaCl, KCl, MgCl2, and CaCl2, spanning various solute fractions. The primary emphasis of the simulations is on unraveling the intricate interplay between these attributes and the underlying physical mechanisms. The configurations of cation-Cl− and Cl−–Cl− pairs within these solutions are disclosed. As the solute fraction increases, consistent trends manifest regardless of solute type: (i) the number of hydrogen bonds formed by the hydration water surrounding ions decreases, primarily attributed to the growing presence of counter ions in proximity to the hydration water; (ii) the hydration number of ions exhibits varying trends influenced by multiple factor; and (iii) the diffusion of ions slows down, attributed to the enhanced confinement and rebound of cations and Cl− ions from the surrounding atoms, concurrently coupled with the changes in ion vibration modes. In our analysis, we have, for the first time, clarified the reasons behind the slowing down of the diffusion of the ions with increasing solute fraction. Our research contributes to a better understanding and manipulation of the attributes of ionic aqueous solutions and may help designing high-performance electrolytes. [ABSTRACT FROM AUTHOR]

We perform molecular dynamics simulations of TIP4P/Ice water in solution with trehalose for 3.65 and 18.57 wt. % concentrations and of bulk TIP4P/Ice water at ambient pressure, to characterize the structure and dynamics of water in a sugar aqueous solution in the supercooled region. We find here that TIP4P/Ice water in solution with trehalose molecules follows the Mode Coupling Theory and undergoes a fragile to strong transition up to the highest concentration investigated, similar to the bulk. Moreover, we perform a Mode Coupling Theory test, showing that the Time Temperature Superposition principle holds for both bulk TIP4P/Ice water and for TIP4P/Ice water in the solutions and we calculate the exponents of the theory. The direct comparison of the dynamical results for bulk water and water in the solutions shows upon cooling along the isobar a fastening of water dynamics for lower temperatures, T < 240 K. We found that the counter-intuitive behavior for the low temperature solutions can be explained with the diffusion anomaly of water leading us to the conclusion that the fastening observed below T = 240 K in water dynamics is only fictitious, due to the fact that the density of water molecules in the solutions is higher than the density of the bulk at the same temperature and pressure. This result should be taken into account in experimental investigations which are often carried out at constant pressure. [ABSTRACT FROM AUTHOR]

CO2 and CH4 hydrates are of great importance both from an energetic and from an environmental point of view. It is therefore highly relevant to quantify and understand the rate with which they grow. We use molecular dynamics simulations to shed light on the growth rate of these hydrates. We put the solid hydrate phase in contact with a guest aqueous solution in equilibrium with the pure guest phase and study the growth of both hydrates at 400 bars with temperature. We compare our results with previous calculations of the ice growth rate. We find a growth rate maximum as a function of the supercooling in all cases. The incorporation of guest molecules into the solid structure strongly decelerates hydrate growth. Consistently, ice grows faster than either hydrate and the CO2 hydrate grows faster than the CH4 one because of the higher solubility of CO2. We also quantify the molecular motion required to build the solids under study and find that the distance traveled by liquid molecules exceeds by orders of magnitude that advanced by any solid. Less molecular motion is needed in order for ice to grow as compared to the hydrates. Moreover, when temperature increases, more motion is needed for solid growth. Finally, we find a good agreement between our growth rate calculations and experiments of hydrate growth along the guest–solution interface. However, more work is needed to reconcile experiments of hydrate growth toward the solution among each other and with simulations. [ABSTRACT FROM AUTHOR]

Nucleotides are organic compounds consisting of a phosphate group, a nitrogenous base, namely adenine (A), thymine (T), cytosine (C), or guanine (G), and a sugar, here deoxyribose. The magnitude of the first hyperpolarizability β of these four DNA nucleotides was determined in aqueous solution with the nonlinear optical technique of hyper rayleigh scattering under non resonant conditions at a fundamental wavelength of 800 nm. The smallest value is found to be 1.67 ± 0.15 × 10−30 esu for thymidine-5′-monophosphate and the highest is 1.76 ± 0.16 × 10−30 esu for 2′-guanosine-5′-monophosphate. Polarization resolved studies were also performed to question the symmetry of the first hyperpolarizability tensor and access the ratio of some elements of the first hyperpolarizability tensor. These experimental results were then compared to the theoretical values of these first hyperpolarizabilities obtained with the density functional theory at the level of the PCM-B3LYP/6-31G+(d) basis and taking into account the solvent. [ABSTRACT FROM AUTHOR]

We demonstrate liquid-jet photoelectron spectroscopy from a flatjet formed by the impingement of two micron-sized cylindrical jets of different aqueous solutions. Flatjets provide flexible experimental templates enabling unique liquid-phase experiments that would not be possible using single cylindrical liquid jets. One such possibility is to generate two co-flowing liquid-jet sheets with a common interface in vacuum, with each surface facing the vacuum being representative of one of the solutions, allowing face-sensitive detection by photoelectron spectroscopy. The impingement of two cylindrical jets also enables the application of different bias potentials to each jet with the principal possibility to generate a potential gradient between the two solution phases. This is shown for the case of a flatjet composed of a sodium iodide aqueous solution and neat liquid water. The implications of asymmetric biasing for flatjet photoelectron spectroscopy are discussed. The first photoemission spectra for a sandwich-type flatjet comprised of a water layer encapsulated by two outer layers of an organic solvent (toluene) are also shown. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV) photolysis of nitrite ions (NO2−) in aqueous solutions produces a suite of radicals, viz., NO·, O−, ·OH, and ·NO2. The O− and NO· radicals are initially formed from the dissociation of photoexcited NO2−. The O− radical undergoes reversible proton transfer with water to generate ·OH. Both ·OH and O− oxidize the NO2− to ·NO2 radicals. The reactions of ·OH occur at solution diffusion limits, which are influenced by the nature of the dissolved cations and anions. Here, we systematically varied the alkali metal cation, spanning the range from strongly to weakly hydrating ions, and measured the production of NO·, ·OH, and ·NO2 radicals during UV photolysis of alkaline nitrite solutions using electron paramagnetic resonance spectroscopy with nitromethane spin trapping. Comparing the data for the different alkali cations revealed that the nature of the cation had a significant effect on production of all three radical species. Radical production was inhibited in solutions with high charge density cations, e.g., lithium, and promoted in solutions containing low charge density cations, e.g., cesium. Through complementary investigations with multinuclear single pulse direct excitation nuclear magnetic resonance (NMR) spectroscopy and pulsed field gradient NMR diffusometry, cation-controlled solution structures and extent of NO2− solvation were determined to alter the initial yields of ·NO and ·OH radicals as well as alter the reactivity of NO2− toward ·OH, impacting the production of ·NO2. The implications of these results for the retrieval and processing of low-water, highly alkaline solutions that comprise legacy radioactive waste are discussed. [ABSTRACT FROM AUTHOR]

A rare all-inorganic high-nuclearity mixed-valent {Mn11} cluster embedded polyoxoniobate, K25H43{(Te4Nb9O33)3(Nb6O19)5(TeVI-Nb5O14)[(TeIVO3)2(MnII7MnIII4 O19)]}•97H2O (1), has been synthesized by a one-pot reaction. Compound 1 contains the largest manganese cluster {Mn11} core among polyoxoniobates reported to date. {Mn11} consists of three quasi-cubane {Mn3O4} units and is simultaneously encapsulated by lacunary α-Keggin {Te4Nb9O36} and Lindqvist {Nb6O19} units. Compound 1 exhibits significant magnetic anisotropy and excellent water solubility and stability. The findings suggest a new, all-inorganic polynulear Mn-based structural paradigm for aqueous solution chemistry and magnetic materials. [ABSTRACT FROM AUTHOR]

AgBiO3 is reported for the exclusive oxidation of Am3+ → AmO2+ at near-neutral pH conditions. Literature methods of AmO2+ generation are generally two-step processes; i.e., Am3+ → AmO22+ oxidation followed by AmO22+ → AmO2+ reduction. These methods for Am3+ → AmO2+ oxidation use high temperatures (80–100 °C) and/or several reagents, causing the in situ presence of the AmO2+-complex rather than the AmO2+aq ions. This not only interferes with the much-needed Am–Cm selectivity but also limits the use of AmO2+aq in any other experimental study. The single-step Am3+ → AmO2+ oxidation in the present work using AgBiO3 is done at 25 °C in a non-complexing medium at pH ∼4, making it a first-of-its-kind report. Am–Eu and Am–Cm separation in a single contact, with a separation factor >104, was achieved using the present method, which is unprecedented among aqueous feed solutions. The AmO2+ generated using the present method under non-complexing pH conditions makes it also suitable for exploring the fundamental chemistry of the higher valent americyl ion. A complexation study using the thus-generated AmO2+ ion with acetate ion supports the concept. [ABSTRACT FROM AUTHOR]

AgBiO3 is reported for the exclusive oxidation of Am3+ → AmO2+ at near-neutral pH conditions. Literature methods of AmO2+ generation are generally two-step processes; i.e., Am3+ → AmO22+ oxidation followed by AmO22+ → AmO2+ reduction. These methods for Am3+ → AmO2+ oxidation use high temperatures (80–100 °C) and/or several reagents, causing the in situ presence of the AmO2+-complex rather than the AmO2+aq ions. This not only interferes with the much-needed Am–Cm selectivity but also limits the use of AmO2+aq in any other experimental study. The single-step Am3+ → AmO2+ oxidation in the present work using AgBiO3 is done at 25 °C in a non-complexing medium at pH ∼4, making it a first-of-its-kind report. Am–Eu and Am–Cm separation in a single contact, with a separation factor >104, was achieved using the present method, which is unprecedented among aqueous feed solutions. The AmO2+ generated using the present method under non-complexing pH conditions makes it also suitable for exploring the fundamental chemistry of the higher valent americyl ion. A complexation study using the thus-generated AmO2+ ion with acetate ion supports the concept. [ABSTRACT FROM AUTHOR]

A highly sensitive method is proposed for obtaining the Raman spectra of low-concentration proteins and nucleic acids in an aqueous solution using liquid–liquid phase separation. This method uses water droplets formed by adding a large amount of polyethylene glycol into a biomolecular aqueous solution. Ordinary spontaneous Raman spectra are obtained with a high signal-to-noise ratio. [ABSTRACT FROM AUTHOR]

The study investigated the structural and dynamical properties of hydrated ion Barium (Ba2+) in aqueous solution using quantum mechanical/molecular mechanical molecular dynamics simulations (QM/MM MD simulation). The primary objective was to assess the performance of the SCAN functional in describing the structure and dynamics of formed Ba2+ hydration shells in aqueous solution. The SCAN/MM MD simulation demonstrated the closest agreement with previously reported experimental data regarding the structural and dynamical properties of hydrated ion Ba2+. Specifically, the Ba2+ and surrounding water molecules distance was determined to be 2.79 Å, with equal distribution of coordination numbers of 8 and 9 in the first hydration shell. Moreover, the stretching frequency of 232.21 cm−1 closely matched the CCSD(T) results. The obtained results from SCAN/MM MD has a better agreement than results from MP2/MM and DKH2 MP2/MM molecular dynamics simulation. These findings underscore the potential of SCAN/MM MD simulation as a promising method for investigating the structural and dynamical properties of hydrated ions. [ABSTRACT FROM AUTHOR]

Amino acids and their salts are amine compounds with great potential for the chemical absorption of CO2 via the amine method. The CO2 absorption properties of various amino acids and their salts have been previously reported. However, the detailed reaction mechanism of CO2 with basic amino acids in aqueous solutions has not yet been clarified. In this study, we focused on arginine (Arg), which has the highest basicity among the standard amino acids, and its monohydrochloride (ArgCl) and sodium (NaArg) salts for the dissolution of CO2 in the aqueous solutions of Arg, ArgCl, and NaArg. CO2 was chemically dissolved in aqueous Arg and NaArg solutions but not in the aqueous ArgCl solution. One‐dimensional 1H and 13C and two‐dimensional 1H‐13C heteronuclear multiple bond correlation nuclear magnetic resonance spectroscopy indicated that the final products in the aqueous Arg and NaArg solutions were protonated Arg and HCO3−. HCO3− was formed from both CO2‐bonded Arg/Arg− and CO32− intermediates in the aqueous NaArg solution but only from the CO2‐bonded Arg/Arg− intermediate in the aqueous Arg solution. In addition to their high environmental and biological compatibility, Arg and NaArg exhibit high CO2 absorption capacity, demonstrating their potential for practical use as naturally derived CO2 chemical absorbents. [ABSTRACT FROM AUTHOR]

Metal ion (Mn+ ${{{\rm M}}^{{\rm n}+}}$ /oxidant) and UV light catalyzed (UV/oxidant) mineralization and biodetoxification of Ponceau Xylidine (PX) was undertaken in this study. Hydrogen peroxide (HP) and ammonium persulphate (APS) were employed as oxidants and Fe2+ ${{{\rm F}{\rm e}}^{2+}}$ and Ag+ ${{{\rm A}{\rm g}}^{+}}$ as metal ion catalysts. Although highest mineralization in Fe2+ ${{{\rm F}{\rm e}}^{2+}}$ /APS and UV/HP systems was exhibited at pH 1 (63.09 %) and 3 (64.83 %), respectively, lowest was shown by Ag+ ${{{\rm A}{\rm g}}^{+}}$ /oxidant systems at any pH. The Fenton process achieved mineralization of ≈48.50 % within the pH range of 3 to 6.15. The study established Fe2+ ${{{\rm F}{\rm e}}^{2+}}$ as a better catalyst than Ag+ ${{{\rm A}{\rm g}}^{+}}$ , and HP, a better oxidant (2.5 times more effective) than APS. Mineralization with UV/HP at 120 min is highest at pH 3 (92.0 %) and 6.15 (86.17 %). Various inorganic anions were found to inhibit mineralization. The maximum and minimum inhibition was shown by Cl- ${{{\rm \ }{\rm C}{\rm l}}^{-}}$ in UV/HP and UV/APS systems respectively. The inhibition effect of NO3- ${{{\rm N}{\rm O}}_{3}^{-}}$ decreases with concentration till 0.01 mM, beyond which an increasing trend was observed. This study also demonstrates that the biodetoxification efficiency of various systems is in the order: UV/HP>UV/APS>Fe2+ ${{{\rm F}{\rm e}}^{2+}}$ /HP. Thus, UV/HP is the most suitable system for the treatment of PX, displaying a biodetoxification efficiency of 83.0 % and mineralization of 92.0 %. [ABSTRACT FROM AUTHOR]

Uncontrolled or improperly managed wastewater is considered toxic and dangerous to plants, animals, and people, as well as negatively impacting the ecosystem. In this research, the use of we aimed to prepare polymer nanocomposites (guar gum/polyvinyl alcohol, and nano-montmorillonite clay) for eliminating heavy metals from water-based systems, especially Cu2+ and Cd2+ ions. The synthesis of nanocomposites was done by the green method with different ratios of guar gum to PVA (50/50), (60/40), and (80/20) wt%, in addition to glycerol that acts as a cross-linker. Fourier-transform infrared spectroscopy (FT-IR) analysis of the prepared (guar gum/PVA/MMT) polymeric nanocomposites' structure and morphology revealed the presence of both guar gum and PVA's functional groups in the polymeric network matrix. Transmission electron microscopy (TEM) analysis was also performed, which verified the creation of a nanocomposite. Furthermore, theromgravimetric analysis (TGA) demonstrated the biocomposites' excellent thermal properties. For those metal ions, the extreme uptake was found at pH 6.0 in each instance. The Equilibrium uptake capacities of the three prepared nanocomposites were achieved within 240 min. The maximal capacities were found to be 95, 89 and 84 mg/g for Cu2+, and for Cd2+ were found to be 100, 91, 87 mg/g for guar gum (80/20, 60/40 and 50/50), respectively. The pseudo-2nd-order model with R2 > 0.98 was demonstrated to be followed by the adsorption reaction, according to the presented results. In less than 4 hours, the adsorption equilibrium was reached. Furthermore, a 1% EDTA solution could be used to revitalize the metal-ion-loaded nanocomposites for several cycles. The most promising nanocomposite with efficiency above 90% for the removal of Cu2+ and Cd2+ ions from wastewater was found to have a guar (80/20) weight percentage, according to the results obtained. [ABSTRACT FROM AUTHOR]

Sodium stearyl polyoxypropylene acetates (SC18PpC, p = 3, 6, 9) were synthesized through a two‐step process involving propoxylation of stearyl alcohol and subsequent carboxymethylation. Stearyl polyoxypropylene acetic acids (C18PpC, p = 3, 6, 9), the acidified products of SC18PpC, were characterized by FT‐IR, 1H‐NMR, and ESI‐MS. The properties of SC18PpC were extensively investigated and compared with sodium dodecanoate (SD) and sodium stearate (SS). The solubility of SC18PpC in cold water was enhanced. Kraft temperature (Tk) of SC18P3C is 40°C which is significantly lower than SS, and Tk of SC18PpC (p = 6, 9) are even less than 0°C. SC18PpC exhibits overall greater hard water resistance compared to SD and SS with the hardness of 0 to 450 mg/L. The hard water resistance of SC18PpC escalates proportionally with the length of the spacer, and the aqueous solution of SC18P9C retains its clarity even when exposed to the hard water of 450 mg/L, the maximum hardness level of Chinese tap water. SC18PpC demonstrates efficiency and effectiveness in reducing surface tension, as well as better foaming, emulsification and wetting power compared to SD and SS. These improved properties make SC18PpC (p = 3, 6) more effective in detergency on three typical soiled fabrics compared to that of sodium soap. Specifically, the detergency to sebum‐stained fabric of SC18P3C exhibits 1.5 times and 1.3 times improvement compared to SD and SS, respectively. Therefore, it is recommended to incorporate SC18PpC (p = 3, 6) in the detergent formulations for washing intimate apparel in tap water. [ABSTRACT FROM AUTHOR]

Aqueous zinc metal batteries are emerging as a promising alternative for energy storage due to their high safety and low cost. However, their development is hindered by the formation of Zn dendrites and side reactions. Herein, a macromolecular crowding electrolyte (MCE40) is prepared by incorporating polyvinylpyrrolidone (PVP) into the aqueous solutions, exhibiting an enlarged electrochemical stability window and anti‐freezing properties. Notably, through electrochemical measurements and characterizations, it is discovered that the mass transfer limitation near the electrode surface within the MCE40 electrolyte inhibits the (002) facets. This leads to the crystallographic reorientation of Zn deposition to expose the (100) and (101) textures, which undergo a "nucleation‐merge‐growth" process to form a uniform and compact Zn deposition. Consequently, the MCE40 enables highly reversible and stable Zn plating/stripping in Zn/Cu half cells over 600 cycles and in Zn/Zn symmetric cells for over 3000 hours at 1.0 mA cm−2. Furthermore, Na0.33V2O5/Zn and α‐MnO2/Zn full cells display promising capacity and sustained stability over 500 cycles at room and sub‐zero temperatures. This study highlights a novel electrochemical mechanism for achieving preferential Zn deposition, introducing a unique strategy for fabricating dendrite‐free zinc metal batteries. [ABSTRACT FROM AUTHOR]

To overcome the challenges associated with the toxicity of the majority of organic solvents for the liquid phase synthesis of solid electrolytes toward the human body and environment, we demonstrate the synthesis of tin-based sulphide electrolytes using water, which is the most environmentally friendly solvent. ortho-Thiostannate, i.e., Li4SnS4, was obtained from a mixture of Li2S, Sn, and S using aqueous solution synthesis. Furthermore, Li10SnP2S12, a superionic conductor, was obtained by mixing an aqueous solution of Li4SnS4 and tetrahydrofuran suspension of Li3PS4, which exhibited the highest ionic conductivity (5.9 × 10−3 S cm−1 at 25 °C) in liquid-phase synthesis. This study successfully demonstrates that water can be efficiently used to synthesize sulphide electrolytes instead of conventional organic solvents. [ABSTRACT FROM AUTHOR]

Linear N‐substituted polyacrylamides bearing tricarboxylic moieties pendant to the backbone are synthesized, and coordinative binding approach is developed to convert them into Gd3+/Eu3+‐metallopolymers. Inner‐sphere coordination of the lanthanide ions with the pendant chelating moieties, together with their outer‐sphere stabilization by the randomly coiled backbone, are the reasons for peculiar water proton relaxation and luminescence properties of the metallopolymers obtained. Indeed, for Gd3+‐metallopolymer, the values of longitudinal and transverse relaxivity (r1 and r2) are 50 and 60 mm−1·s−1, respectively, while for the Eu3+‐counterpart, Eu3+‐centered luminescence is significantly raised compared to Eu3+ aquaions. Coil‐like conformation of the metallopolymer molecules undergoes a swelling at pH values above 5.0 as evidenced by transmission electron microscopy TEM and dynamic light scattering (DLS) data, which is followed by the changes in the Eu3+‐centered luminescence and r1(2)‐values of Gd3+/Eu3+‐metallopolymers. The phosphates additives (adenosine monophosphoric acid (AMP), adenosine diphosphoric acid (ADP), HPO42− and adenosine triphosphoric acid (ATP) induce well detectable changes in both water proton relaxation and luminescence of Gd3+/Eu3+‐metallopolymers. The luminescent changes distinguish AMP from the other phosphates, while the changes in water proton relaxation are greater for HPO42− and ATP compared to AMP and ADP. This study explains this by interplay of the effects associated with the formation of ternary phosphate‐lanthanide‐polymer complexes and stripping of lanthanide ions from the polymer molecules. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Cachaça (Brazilian spirit) is an alcoholic beverage of cultural and economic importance in Brazil. Its artisanal production is usually conducted in copper alembics, which results in contamination. The development of effective biosorbents from cheap matrices is an alternative to minimize both solid waste generation and copper levels in cachaça. The present work evaluates the obtention of nanocellulose‐based materials from the major residue generated during the processing of palm heart from the Brazilian peach palm, through different processing techniques. Materials were characterized by physicochemical composition and their sorbent capacities for copper removal from aqueous solutions, and a simulation was conducted to evaluate potential application in the adequacy of cachaça to meet Brazilian legislation requirements.The different processing methods resulted in different cellulose concentrations, with the highest concentration in the bleached material (B3, 694 g kg−1 of cellulose), and different specific surface areas (1.02–12.4 m2 g−1). Copper adsorption onto nanocellulose obtained from peach palm external sheath is fast, with a predominance of a chemisorption mechanism. Isotherms were best represented by Langmuir's model, suggesting a monolayer adsorption. Simulations indicate that B3 is a suitable material for the removal of copper from cachaça, and small amounts of biosorbent (733.5 g) are required for the reduction of copper concentrations (10 to 3 mg L−1) in 1000 L of cachaça.This study demonstrated that the obtention of biosorbents from peach palm solid residues is promising and this nanocellulose‐based material can be used for copper removal from contaminated cachaça. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Molecules involved in solvation shells have properties differing from those of the bulk solvent, which can in turn affect reactivity. Among key properties of these molecules are their nature and electronic structure. Widely used tools to characterize this type of property are X-ray-based spectroscopies, which, however, usually lack the capability to selectively probe the solvation-shell molecules. A class of X-ray triggered "non-local" processes has the recognized potential to provide this selectivity. Intermolecular Coulombic decay (ICD) and related processes involve neighbouring molecules in the decay of the X-ray-excited target, and are thus naturally sensitive to its immediate environment. Applying electron spectroscopy to aqueous solutions, we explore the resonant flavours of ICD and demonstrate how it can inform on the first solvation shell of excited solvated cations. One particular ICD process turns out to be a potent marker of the formation of ion pairs. Another gives a direct access to the electron binding energies of the water molecules in the first solvation shell, a quantity previously elusive to direct measurements. The resonant nature of the processes makes them readily measurable, providing powerful new spectroscopic tools. X-ray triggered non-local processes, such as Intermolecular Coulombic Decay, are shown here to selectively probe solvation-shell molecules in solution and provide new information on their electronic structure and on ion-pair formation. [ABSTRACT FROM AUTHOR]

Solvothermal synthesis is the predominant method for creating new structured covalent organic frameworks (COFs), yet it grapples with challenges in controlling shape and morphology. This issue is attributed to the unregulated solvent‐feeding process, which results in rapid polymerization and uncontrolled phase separation. Consequently, a two‐step solvent‐feeding process is reported for the solvothermal shaping of imine‐linked COF monoliths with hierarchical porosity. The synthesis conditions for COF powders reported in existing literature are directly utilized without extensive optimization; however, solvents are divided into two segments prior to feeding. A minor segment of solvents is employed to dissolve monomers, which polymerize in situ to form amorphous monoliths. Subsequently, the remaining organic solvent, along with an acetic acid aqueous solution, is added for crystallization. The versatility of this two‐step feeding process in producing COF monoliths is illustrated. The high‐quality COF monoliths demonstrate benzene uptakes ranging from 6.0 to 16.8 mmol g−1 at 298 K. This study confirms that the two‐step solvent feeding process can be effectively integrated with the conventional solvothermal method to enhance the solution‐processability of COFs. It is anticipated that this modified solvothermal approach can readily shape COFs to meet practical application requirements. [ABSTRACT FROM AUTHOR]

This work describes a molecular dynamics simulation study (MP2‐DKH2/MM) that explores the structural and dynamical properties of hydrated Ac3+ ions in an aqueous solution. Simulation results indicate that the ion formed three hydration shells. The hydrated Ac3+ had a first hydration shell comprising 8–9 water molecules. It showed similar probabilities for both coordination numbers, showing a flexible first hydration shell with eight registered successful ligand exchanges during the simulation. The water molecules' mean residence times (MRT) in the first, second, and third hydration shells were 131.8, 6.46, and 2.67 ps, respectively. The complexes of octahydrate ([Ac(H₂O)₈]3+) and nonahydrate ([Ac(H₂O)₉]3+) were observed in the first hydration shell. The square antiprism (SA) geometry was adopted for octahydrate, while the gyroelongated square antiprism (GySA) geometry was adopted for nonahydrate. The simulations provided valuable insights into the ion‐oxygen stretching frequencies. Specifically, the average stretching frequency for Ac3+ was found to be 404 cm−1, which is in good agreement with the calculated value from the CCSD(T) calculation of 398.78 cm−1. These findings indicate that including DKH2 relativistic approximation increases the accuracy of the simulation results and can contribute to understanding these actinide ions' behavior in aqueous environments, shedding light on hydrated systems' structural arrangements and dynamics. [ABSTRACT FROM AUTHOR]

The detection of excess toxic anions or cations in an aqueous solution through various fluorescent materials such as organic or inorganic fluorescent materials has aroused significant interest recently. Herein, a new tetraimidazole ligand 1,3-bis(1-imidazolyl)-5-[3,5-bis(1-imidazolyl)-phenoxymethyl]-benzene (timpb) and its two Cd(II) metal–organic frameworks {[Cd2(1,4-bdc)2(timpb)]·5.5(H2O)}n (1) (1,4-benzenedicarboxylic acid = 1,4-H2bdc) and {[Cd2(4,4′-bpdb)2(timpb)]·(MeCN)·2.5(H2O)}n (2) (4,4′-biphenyldicarboxylic acid = 4,4′-H2bpdb) were synthesized. Through X-ray single crystal diffraction analysis, 1 can be considered as a 2-fold interpenetrating pillared-bilayer framework formed by linking [Cd2(1,4-bdc)4]n layers with pairs of timpb ligands, whereas 2 exhibits a 2-fold interpenetrating 3D honeycombed framework formed by linking [Cd(4,4′-bpdb)]n chains with timpb ligands. The solid-state luminescent properties of timpb, 1 and 2 at ambient temperature were also investigated. Moreover, timpb acted as a potential luminescent sensor for the detection of cations Fe3+ or Cu2+ and the anion Cr2O72−, whereas 1 displayed high sensitivity toward the cation Fe3+ and anion Cr2O72−. [ABSTRACT FROM AUTHOR]

Spontaneous and directional water droplet transportation based on patterned surface with super-wettability is crucial for the development of frontier science technology. However, water droplet transportation cannot meet both long distance and fast transportation simultaneously. Here, we overcame this limitation by proposing an asymmetric serial brachistochrone-shaped pattern (ASBP). Water droplet could be transported on the ASBP with a transportation distance of 72.52 mm and a transportation velocity of 158 mm/s after a series of single-factor experiments, orthogonal design optimization, and junction transition optimization. In addition, the water droplet could be transported on a curved ASBP, a super-long ASBP for multi-droplet scenarios, and an ASBP at an inclination angle. Moreover, acidic and alkaline aqueous solution droplet showed similar transportation distance and transportation velocity on the ASBP. Based on the aforementioned superb water transportation capacity, this ASBP can be applied in the fields of fog collection, solution mixing and reaction, and reagent detection. This work has strong implications for promoting the application of patterned surface with super-wettability in the field of high-performance fluid transportation systems. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate the unique role of ionic liquids (ILs) as dye aggregation and precipitation promoter. Specifically, we have observed that the presence of small amount of IL such as 1‐butyl‐3‐methylimidazolium hexaflurophosphate ([bmim][PF6]), 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([bmim][Tf2N]), 1‐butyl‐3‐methylimidazolium trifluoromethanesulfonate ([bmim][OTf]), 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([bmim][BF4]) and 1‐butyl‐1‐methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([bmpyrr][Tf2N]) in aqueous milieu can help in the conversion of a cyanine dye 1,1'‐Diethyl‐2,2'‐carbocyanine iodide (Pinacyanol iodide) into J‐ and H‐aggregates followed by time dependent precipitation of the dye. The anion of the added IL strongly affects the aggregation process in aqueous solution. Addition of small amount of BF4− anion based IL [bmim][BF4] to aqueous solution of the dye initially induces J‐ and H‐aggregation followed by quick precipitation of the dye in time dependent manner. Presence of small amount of other anion containing ILs such as ([bmim][PF6]), ([bmim][OTf]), ([bmim][Tf2N]) and ([bmpyrr][Tf2N]) strongly supports H‐aggregation of the dye in aqueous solution whereas higher wt % of added ILs also caused precipitation of the dye in a time dependent manner. The nature of the IL anion, wt % of added IL and temperature conditions decides efficiencies of aggregation and precipitation processes. The dual yet unique behavior of ILs as an additive influence the aggregation of cyanine dyes and precipitation has been demonstrated. The observed results can contribute towards various application for dye aggregates and in the removal of dyes from water. The developed process can find potential applications in the field of material science, wastewater treatment, future light harvesting systems, and opto‐electronics related fields. [ABSTRACT FROM AUTHOR]

Intelligent‐responsive temporary plugging agents (TPAs) have great potential in the field of oil and gas resource extraction due to their self‐adaptability to the environment. However, the transport mechanism of oil and gas molecules, such as aqueous methane solution in intelligent‐responsive TPA‐modified nano‐channels and the blocking behavior of TPA, have not been verified yet. In this work, dissipative particle dynamics simulations (DPD) are conducted to investigate the velocity distribution and the force characteristics of aqueous methane solutions under different driving velocities, as well as the blocking effect of TPA to the flow of solution. Simulation results indicate that aqueous methane solution primarily concentrates in the uncovered area of the TPA and diffuses into the TPA‐covered area when the nano‐channel is closed. The velocity distribution of the flowing solution in the open nano‐channel follows a subparabolic pattern. Methane molecules in the closed nano‐channel show sharp oscillations in velocity and force profiles, which can be mitigated by increasing the methane concentration. The designed TPA effectively blocks fluid flow but its head and tail are vulnerable to the shear forces from the fluid. This study enhances the understanding of the nanoflows in the wellbores during the extraction of oil and natural gas resources. [ABSTRACT FROM AUTHOR]

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The current study is to develop surface-modified peanut shell granules by incorporating activated carbon to enhance the removal efficiency of Orange G dye (OGD) through adsorption. Activated carbon was prepared from Arachis hypogaea shell (Peanut shell) using a chemical activation method. Ultrasonic Activated Peanut Shell Powder (UAPSP) was characterised using FT-IR and SEM analysis to identify functional groups and assess surface morphology. To determine the optimal conditions, a batch adsorption study was conducted. The results indicated a maximum removal efficiency of 99.5% and a maximum adsorption capacity of 298.36 mg/g under the following parameters: pH 5, temperature 303 K, interaction period of 60 min, a dosage of 0.5 g/L for an OGD concentration of 10 mg/L. The adsorption mechanism in the current system was evaluated using the Langmuir, Freundlich, Sips, Temkin, and D-R isotherms models. Among these, the Langmuir isotherm exhibited the best fit with an R2 value of 0.997. UAPSP demonstrated a monolayer adsorption capacity of 1.9 mg/g for OGD removal. The pseudo-second-order kinetic model provided the most effective fit with an R2 value of 0.998. Thermodynamic studies revealed that the adsorption process was spontaneous and exothermic, as evidenced by the negative values of ΔG° (−1.497) and ΔS° (16.4052) at 303 K. Additionally, the mean free energy value (E) in the D-R isotherm increased to 10.58 KJ/mol with a temperature rise from 303 K to 343 K. The characterisation results confirmed that UAPSP is an effective, cost-free, and commercial alternative adsorbent for the removal of hazardous dyes from wastewater. [ABSTRACT FROM AUTHOR]

The surplus phosphorus in aquatic environments trigger eutrophication, an irreversible pollution stage marked by the rapid growth of algae and water plants, a decline in dissolved oxygen levels, and the emergence of dead zones. To address this critical issue, this study focuses on the removal of phosphorus in form of phosphate from aqueous solutions. The research involves the synthesis and characterization of FeCl3‐immobilized melamine‐formaldehyde‐urea resin, an innovative adsorbent, its characterization through Fourier transform infrared spectroscopy, and the evaluation of its adsorption capacity based on Langmuir and Freundlich equilibrium models. The experimental adsorption data fits well with pseudo‐second order kinetic model. Optimal adsorption parameters are carried with batch adsorption technique for 60 min using 0.5 g of adsorbent at pH = 2, achieving 15.55 mg g−1 adsorption capacity, and conducting experiments with tap‐water samples to replicate real‐world scenarios. The research findings have the potential to advance sustainable wastewater treatment technologies and contribute to the mitigation of nutrient pollution in aquatic ecosystems, addressing a pressing environmental concern. [ABSTRACT FROM AUTHOR]

Amino acid surfactants have mild performance and are sourced from renewable biomass. Compared to classical surfactants, Gemini surfactants have superior properties. The amino acid Gemini surfactants are believed to be adopted more widely. The Gemini surfactant with tripeptide structure, sodium di(lauroyl glutamyl) lysine (DLGL), was prepared by amidation utilizing methyl laurate, glutamate and lysine and characterized by 1H NMR, 13C NMR and MS. Additionally, the pKa value, surface activities, aggregation, foaming properties and emulsifying attributes of the DLGL surfactant in aqueous solution with varied pH values were examined. The results indicate that the protonation‐deprotonation behavior of the DLGL surfactant is highly dependent on pH values. The surface tension, critical micelle concentration (cmc), foamability and foam stability exhibited superior performance at pH 6 and 7. Conversely, superior emulsifying ability was observed at pH 9 and 10. Moreover, the spherical vesicles were formed by the DLGL surfactant at pH 6, 7 or 8 while the micelles were generated at pH 9 or 10. [ABSTRACT FROM AUTHOR]

Oxalate plays a crucial role in various biological and industrial applications. Its involvement in diseases, drug‐ and toxin‐induced disorders, and disruption of industrial processes makes it a high‐priority chemical for the development of more precise, selective, and straightforward analytical methods. Herein, an innovative and efficient strategy for sequentially measuring Cu2+ and oxalate ions is reported. During an indicator displacement process, where Cu2+ and azo dye, ArsenazoIII (AAIII), are used as receiver and indicator, respectively, oxalate (C2O42−) is measured by a colorimetric method. Proof of concept results from UV–visible spectroscopy, naked eye, and signal reset of the indicator revealed a more robust interaction of the Cu2+ receptor with C2O42− than the AAIII indicator with high selectivity, good sensitivity, and lower detection limit(4.01 × 10−8 and 3.04 × 10−9mol L−1, for Cu2+ and C2O42−, respectively). The results of measuring C2O42− in actual samples (urine, mushrooms, and spinach) showed the applicability of the existing method. Most importantly, the colorimetric system based on molecular exchange in the indicator dislocation proceeding can serve as a colorimetric INHIBIT logic‐gate. It works like a molecular keypad lock system that can be controlled by two users with two different sets of chemical passwords (inputs) that can be identified through optical paths. [ABSTRACT FROM AUTHOR]

Ammonia electrooxidation in aqueous solutions can be a highly energy‐efficient process in producing nitrate and nitrite while generating hydrogen under ambient conditions. However, the kinetics of this reaction are slow and the role of catalyst in facilitating ammonia electrooxidation is not well understood. In this study, a high‐performance NiOOH‐Ni catalyst is introduced for converting ammonia into nitrite with Faraday efficiency of up to 90.4% and nitrate production rate of 1 mg h−1 cm−2. By employing Operando techniques, the role of NiOOH catalyst is elucidated in the dynamic electrooxidation of ammonia. Density functional theory (DFT) calculations support experimental observations and reveal the mechanism of the electrochemical oxidation of ammonia to nitrite and nitrate. Overall, this research contributes to the development of a cost‐effective and highly efficient catalyst for large‐scale ammonia electrolysis, while shedding light on the underlying mechanism of the NiOOH catalyst in ammonia electrooxidation. [ABSTRACT FROM AUTHOR]

Combining the potency of non-covalent halogen bonding (XB) with metal ion coordination, the synthesis and characterisation of a series of hydrophilic XB tripodal Cu(II) metallo-receptors, strategically designed for tetrahedral anion guest binding and sensing in aqueous media is described. The reported metallo-hosts contain a tripodal C3-symmetric tris-iodotriazole XB donor anion recognition motif terminally functionalised with tri(ethylene glycol) and permethylated β-cyclodextrin functionalities to impart aqueous solubility. Optical UV-vis anion binding studies in combination with unprecedented quantitative EPR anion titration investigations reveal the XB Cu(II) metallo-receptors exhibit strong and selective phosphate recognition over a range of other monocharged anionic species in competitive aqueous solution containing 40% water, notably outperforming a hydrogen bonding (HB) Cu(II) metallo-receptor counterpart. Electrochemical studies demonstrate further the capability of the metallo-receptors to sense anions via significant cathodic perturbations of the respective Cu(II)/Cu(I) redox couple. [ABSTRACT FROM AUTHOR]

Asphaltene, often regarded as an undesirable by‐product of petroleum processing, possesses abundant reserves but limited market value. In this study, a simple and environmentally friendly solvent extraction method is conducted under ambient conditions to convert low‐value asphaltene into high‐value asphaltene‐based fluorescent carbon nanosheets (a‐FCS). This approach yields dual‐switch a‐FCS capable of emitting orange‐red fluorescence in solid‐state or water environment and exhibiting blue‐to‐yellow fluorescence in organic solvents. Moreover, the redshift observed in the fluorescence emission wavelength in the solvent is attributed to its intrinsic self‐assembly behavior, which becomes more pronounced with increasing concentration. Upon introduction to water, hydrophobic interactions induce the aggregation of a‐FCS. This aggregation triggers the orange‐red fluorescence by restricting intramolecular rotation on the surface, a phenomenon facilitated by the entanglement of aliphatic chains from asphaltene molecules. This unique property makes them applicable in anti‐counterfeiting and determination of ethanol content in aqueous solution. [ABSTRACT FROM AUTHOR]

A high‐quality filler within mixed matrix membranes, coupled with uniform dispersity, endows a high‐efficiency transfer pathway for the significant improvement on separation performance. In this work, a zeolite‐typed MCM‐22 filler is reported that is doped into polydimethylsiloxane (PDMS) matrix by ultrafast photo‐curing technique. The unique structure of nanosheets assembly layer by layer endows the continuous transfer channels towards penetrate molecules because of the inter‐connective nanosheets within PDMS matrix. Furthermore, an ultrafast freezing effect produced by fast photo‐curing is used to overcome the key issue, namely filler aggregation, and further eliminates defects. When pervaporative separating a 5 wt% ethanol aqueous solution, the resulting MCM‐22/PDMS membrane exhibits an excellent membrane flux of 1486 g m−2 h−1 with an ethanol separation factor of 10.2. Considering a biobased route for ethanol production, the gas stripping and vapor permeation through this membrane also shows a great enrichment performance, and the concentrated ethanol is up to 65.6 wt%. Overall, this MCM‐22/PDMS membrane shows a high separation ability for ethanol benefited from a unique structure deign of fillers and ultrafast curing speed of PDMS, and has a great potential for bioethanol separation from cellulosic ethanol fermentation. [ABSTRACT FROM AUTHOR]

This study is concerned with the physicochemical investigation of cobalt (II) sorptions from aqueous solution by potato peel (PP) and NaOH/CaCl2/C2H5OH‐modified potato peel (MPP). The sorption conditions of PP and MPP under optimized conditions were optimized according to the maximum effects of the main factors affecting the sorption processes (PP and MPP dosage, sorbate concentration, interaction time, and temperature) at pH 6.78. The kinetic and equilibrium experimental sorption data of the studied sorbates were simulated using commonly used models and were found to fit well with pseudo‐second‐order and Langmuir models. The Co(II) ion adsorption capacity of PP was determined as 12.25, 16.44, and 20.74 mg/g, respectively, at various temperatures (25, 35, and 45 °C), while the adsorption capacity of MPP under the same conditions was determined as 41.49, 52.35, and 62.50 mg/g. Thermodynamic parameters determined for each sorption system showed that the sorption processes were endothermic and spontaneous. The results of this study emphasize that both PP and MPP can be used as effective sorbents for removing pollutants from water. [ABSTRACT FROM AUTHOR]

Glyceric acid (GA), a carboxylic group-containing diol, is obtained from bioresources via microbial processes. In this study, we aimed to develop a reactive extraction method to separate GA from aqueous solutions using 2-naphthaleneboronic acid (2NB) and tri-octyl methyl ammonium chloride (TOMAC). Different feed molar amounts of 2NB (0–25 µmol), TOMAC (0–500 µmol), and NaOH (0–250 µmol) were used for GA (2.5 µmol) separation. A combination of 25 µmol 2NB, 100 µmol TOMAC, and 25 µmol NaOH was determined to be optimal for GA separation, providing 66.8 ± 3.2% GA yield at pH 11. GA was extracted by 2NB and TOMAC in a coordinated manner. Moreover, effects of various carboxylic acids (acetic, lactic, succinic, malic, tartaric, and citric acids) on GA separation from aqueous solutions were investigated. Interestingly, no significant effect on GA yeild (60.3 ± 1.2–65.2 ± 2.5%) was observed regardless of the type of carboxylic acid. The optimized protocol was subsequently applied to separate GA from crude GA solution prepared by incubating glycerol with the cells of the acetic acid bacterium, Acetobacter tropicalis NBRC 16470. GA separation was achieved at a comparable level (yield: 70.6 ± 4.6% and purity: 76.1 ± 4.1%) as that achieved using a GA reagent. This study demonstrated the efficiency of the repeated use of the organic phase for GA separation, with no significant changes in GA yield. [ABSTRACT FROM AUTHOR]

In this work, the role of ascorbic acid in the process of azo dye degradation was explained. For this purpose, the kinetics of azo dye degradation under different conditions was studied. Among them, the influence of daylight protection/exposition, different concentrations of ascorbic acid (0.567–0.014 mol/dm3), and temperature (20 °C and 50 °C) on the rate of the dyes' degradation was considered. For this process, the kinetic equation was proposed, which indicates that the process of azo dye degradation using ascorbic acid is first order. Moreover, the observed rate constants were determined, and the mechanism of azo dye degradation was proposed. Spectrophotometry results, together with FTIR, fluorescence spectroscopy, and DFT calculations, explain the origin of the decolorization of the azo dyes and highlight the role of ascorbic acid in this process. Detailed analysis of the obtained products indicates that the process itself goes through several stages in which equally or more toxic compounds are formed. Obtained results from LCMS studies indicate that during tropaeolin OO degradation, 1,2-Diphenylhydrazine (m/z 185.1073) is formed. Thus, the process of azo dye degradation should be carried out in protective conditions. The proposed mechanism suggests that ascorbic acid at high content levels can be used for azo dye degradation from aqueous solution and can be an alternative method for their removal/neutralization from waste solution but with caution during the process. [ABSTRACT FROM AUTHOR]