Investigation of solvation of ammonium salts: A Raman spectroscopy and <i>ab initio</i> study

Mukhopadhyay, Anamika; Dubey, P K

doi:10.1002/jrs.5322

Cited by 12 publications

(9 citation statements)

References 87 publications

(128 reference statements)

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“…Compared with pure water, in the curve of 60.0 wt% maltose solution, the band related to v (CH) contributed by maltose molecules appears in the region below 3000 cm, and the v (OH)‐related band in the region above 3000 cm is significantly decreased, which means the reduction of OH stretching. [ 31,32 ] After the addition of 2 M NaNO 3 , as the increase of maltose concentration, the intensity of v (CH) band gradually improves, while the intensity of the v (OH) band gradually decreases, manifesting that the v (OH) band and the concentration of maltose are negatively correlated. Figure 2b shows the simulated Raman spectrum of pure water, in which four v (OH)‐based bands are obtained.…”

Section: Figurementioning

confidence: 99%

“…The band at 3024 cm (O1) corresponds to the intermolecularly coupled vibrations (moving in phase with one another), the band at 3218 cm (O2) represents OH stretching vibrations of water molecule (moving collectively in phase with the nearest and following nearest neighbors), and bands at 3408 and 3556 cm (O3 and O4, respectively) correspond to the OH stretching in partially H‐bonded water (O3 and O4, respectively). [ 29,31 ] Figure 2c–f presents the simulated Raman spectra of 60.0 wt% maltose, 2 M NaNO 3 /20.0 wt% maltose, 2 M NaNO 3 /40.0 wt% maltose, and 2 M NaNO 3 /60.0 wt% maltose solutions, where the v (CH)‐related bands are fitted into two bands (C1 and C2). After the addition of maltose, we can find that the O1 band disappears, and as the concentration of maltose increases, the proportion of O2 band reduces significantly, and the proportion of O4 band enhances distinctly.…”

Section: Figurementioning

confidence: 99%

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A Universal Approach to Aqueous Energy Storage via Ultralow‐Cost Electrolyte with Super‐Concentrated Sugar as Hydrogen‐Bond‐Regulated Solute

et al. 2020

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Compared with the organic, ionic liquid, and solid-state electrolytes, aqueous electrolytes have the advantages of good security, environmental friendliness, high ionic conductivity, low cost, and high operability in ordinary environments. [1][2][3][4][5] Therefore, aqueous secondary ion batteries/capacitors are more attractive in large-scale energy storage, and have greater application prospects. [6][7][8][9] However, even so, there still exists several disadvantages as follows: 1) The thermodynamic electrochemical stability window (ESW) of water is as narrow as 1.23 V. Even considering the existence of overpotential, the ESWs of conventional aqueous electrolytes are not higher than 2 V. 2) Usually, the electrode materials cannot form stable interface in water, so it is difficult to ensure the cycling stability. 3) Dissolution and even decomposition of electrode materials and discharge/charge products limit the choice of electrode materials. [10] These factors have limited the improvement of key electrochemical performance indicators such as energy density, output voltage, and cycle life of aqueous energy-storage devices Aqueous energy-storage systems have attracted wide attention due to their advantages such as high security, low cost, and environmental friendliness. However, the specific chemical properties of water induce the problems of narrow electrochemical stability window, low stability of water-electrode interface reactions, and dissolution of electrode materials and intermediate products. Therefore, new low-cost aqueous electrolytes with different water chemistry are required. The nature of water depends largely on its hydroxylbased hydrogen bonding structure. Therefore, the super-concentrated hydroxyl-rich sugar solutions are designed to change the original hydrogen bonding structure of water. The super-concentrated sugars can reduce the free water molecules and destroy the tetrahedral structure, thus lowering the binding degree of water molecules by breaking the hydrogen bonds. The ionic electrolytes based on super-concentrated sugars have the expanded electrochemical stability window (up to 2.812 V), wide temperature adaptability (-50 to 80 °C), and fair ionic conductivity (8.536 mS cm −1 ). Aqueous lithium-, sodium-, potassium-ion batteries and supercapacitors using super-concentrated sugar-based electrolytes demonstrate an excellent electrochemical performance. The advantages of ultralow cost and high universality enable a great practical application potential of the superconcentrated sugar-based aqueous electrolytes, which can also provide great experimental and theoretical assistance for further research in water chemistry.

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Section: Figurementioning

confidence: 99%

Section: Figurementioning

confidence: 99%

A Universal Approach to Aqueous Energy Storage via Ultralow‐Cost Electrolyte with Super‐Concentrated Sugar as Hydrogen‐Bond‐Regulated Solute

et al. 2020

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“…Mukhopadhyay and Dubey investigated solvation of ammonium salts using Raman measurements and ab initio calculations. Their study helps understand the effect of salt water interaction at the molecular level and may have strong implications in atmosheric physics, geophysics, and ice crystallization . Pattenaude and colleagues presented temperature‐ and polarization‐dependent Raman spectra of liquid H 2 O and D 2 O.…”

Section: Liquids Solutions and Liquid Interactionsmentioning

confidence: 99%

“…Their study helps understand the effect of salt water interaction at the molecular level and may have strong implications in atmosheric physics, geophysics, and ice crystallization. [179] Pattenaude and colleagues presented temperature-and polarization-dependent Raman spectra of liquid H 2 O and D 2 O. The spectral component whose intensity increases with decreasing temperature contains prominent features in both the high-frequency OH stretch band region and low-frequency OH···O hydrogen bond stretch band region that resemble those observed in single crystal ice Ih and clathrate hydrates.…”

Section: Metals Carbons and Other Crystalline Materialsmentioning

confidence: 99%

Recent advances in linear and nonlinear Raman spectroscopy. Part XIII

Nafie

2019

J Raman Spectroscopy

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This article is an overview of advances in Raman spectroscopy published in 2018 in the Journal of Raman Spectroscopy (JRS) and, in addition, trends over the past decade across journals that have published papers important to the field of Raman spectroscopy. The trends are based on statistical data of article counts obtained from Clarivate Analytic's Web of Science Core Collection byyear and by subfield of Raman spectroscopy. Coverage is provided for presentations involving Raman spectroscopy at four international conferences this published in JRS in 2018 are highlighted and arragned by topics at the frontier of Raman spectroscopy. Based on these data, presentations, and publications, it is clear that Raman spectroscopy continues as an expanding field of research across a wide range of novel disciplines and applications that provide sensitive photonic information at the molecular level.KEYWORDS advances in Raman spectroscopy, applications of Raman spectroscopy, developments in Raman spectroscopy, review

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“…Raman signal increased obviously with the increase of the laser intensity [9,10], and the use of droplet inversion and ultra-thin glass expand the application of high magnification short focus objectives in solution Raman testing, which further significantly improves the signal. Figure 3 is a typical Raman spectrum of hexahydrate nickel sulfate (NiSO 4 ·6H 2 O) aqueous solution which is divided into two regions to analyze variations of sulfate ions and water molecules [11,12]. Through rapid and continuous scanning of these two regions, Figure 1 (Color online) Schematic drawing of chemical bonding during nucleation.…”

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confidence: 99%

In-situ micro-spectroscopy technique for chemical bonding during nucleation: A transition from soft bond to stiff bond

Xue

Wang

2020

Sci. China Technol. Sci.

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In-situ technique has been widely used in recent years since the advent of high-resolution spectroscopy systems, which stimulates us to probe into the time-dependent, dynamic behaviors and relevant mechanisms during a series of physical processes [1]. Especially, in-situ analysis presents a unique real-time glimpse into the fascinating physical phenomena [2], which are very important to develop the materials for subsequent applications. Generally speaking, the nucleation process involves dynamic changes in the cluster structures, as well as the formation and transformation of chemical bonds, which requires in-situ analysis urgently [3].The idea of chemical bonding provides novel insights into the nucleation process [4,5] which can be expressed as a chemical equation as follows:where C is the cluster, N s is the small size nucleus and N l is the large size nucleus. This model contains two fundamental assumptions: entropy change approximation and chemical bond softening. In the first assumption, entropy change may be assumed negligible when individual small size clusters are combined into larger clusters. This means that reduction of the whole system energy comes from the released energy via forming chemical bonds when clusters become combined. This also makes it possible to use bond energy (bond enthalpy) [6] to describe free energy variation of the system. In the second assumption, ions with similar resonance status[7] often combine to form clusters, and the clustering structure is constantly changing due to chemical bonds softening. Different chemical bonding is the key to distinguish the state of the system. As shown in Figure 1, the asformed clusters via those soft chemical bonds belong to a kind of amorphous state. When the size is large enough, the soft chemical bonds transform into stiff ones, resulting in a further reduction in energy. This marks the formation of a nucleus with a crystalline structure which has the lowest energy and therefore no longer changes dynamically.We have proposed and experimentally demonstrated the in-situ micro Raman characterization technique of chemical bonding behaviors driven by electronegativity [8]. As shown in Figure 2, in a modified setup, the emission from a single droplet can be excited in-situ under a laser scanning. The sample information about chemical bonding in aqueous system can be characterized in-situ by a series of spectra. High spatial resolution and the design of the bottom droplets make it possible to observe nucleation in real time. Raman signal increased obviously with the increase of the laser intensity [9,10], and the use of droplet inversion and ultra-thin glass expand the application of high magnification short focus objectives in solution Raman testing, which further significantly improves the signal. Figure 3 is a typical Raman spectrum of hexahydrate nickel sulfate (NiSO 4 ·6H 2 O) aqueous solution which is divided into two regions to analyze variations of sulfate ions and water molecules [11,12]. Through rapid and continuous scanning of these two r...

show abstract

Investigation of solvation of ammonium salts: A Raman spectroscopy and ab initio study

Cited by 12 publications

References 87 publications

A Universal Approach to Aqueous Energy Storage via Ultralow‐Cost Electrolyte with Super‐Concentrated Sugar as Hydrogen‐Bond‐Regulated Solute

A Universal Approach to Aqueous Energy Storage via Ultralow‐Cost Electrolyte with Super‐Concentrated Sugar as Hydrogen‐Bond‐Regulated Solute

Recent advances in linear and nonlinear Raman spectroscopy. Part XIII

In-situ micro-spectroscopy technique for chemical bonding during nucleation: A transition from soft bond to stiff bond

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