bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Photocurrent X-Ray Spectroscopy: A Novel Analytical Surface Technique
Authors: Strom Matthew James , Roeper Donald F. , Natishan Paul M. , O'Grady William E. 
Published: February 2020

X-ray absorption spectroscopy (XAS) is a powerful tool for characterizing the chemical nature and environment of atoms in molecules. However, in situ techniques are limited to transmission and fluorescence techniques and are not surface sensitive. A novel in situ technique that uses synchrotron radiation to produce photoelectrons was developed to provide information on the surface and near surface regions. The results obtained from this technique, Electrochemical Photocurrent X-ray Spectroscopy (EPXS) were compared transmission and fluorescence X-ray absorption spectroscopy (XAS). Surface sensitive information was obtained by collecting X-ray induced photocurrent from a polarized electrode. An Au working electrode in 0.1 N H2SO4 was polarized to 300 mVSCE and exposed to high energy X-rays. The photocurrent response was recorded during Au L3 edge scans while X-ray fluorescence yield data was collected concurrently. The photocurrent data showed good agreement with fluorescence data and transmission data collected on Au foils (Figure 1). Investigations using electrochemical impedance spectroscopy and cyclic voltammetry we conducted to insure the photocurrent response was not due to double layer charging or solution radiolysis. Minor differences in peak characteristics were observed between photocurrent and fluorescence data. We believe this to be due to the surface sensitivity of the photocurrent technique. A comparison of the surface sensitivity of fluorescence and photocurrent techniques was accomplished by evaluating signal response to X-ray beam intensity changes. The results show that the photocurrent technique, as expected, was more surface sensitive than fluorescence. Current work is focusing on EXAFS analysis of photocurrent spectra to quantify the techniques surface sensitivity.
This novel technique has the potential to provide information on electron distribution on conductive surface atoms and changes in charge of surface atoms as a function of electrochemical potential. It could significantly impact fields where measurements of surface electron distribution during electrochemical charge transfer are of primary importance, such as corrosion, catalysts and semiconductor research.
Figure 1- XAS spectrum of Au foil using transmission (left) and a spectrum of Au in 0.1N H2SO4 polarized to 300 mVSCE using the photocurrent technique.

Figure 1
Influence of Ion Diffusivity and Gas Solubility in Ionic Liquids on Li-Air Battery Performance
Authors: Seo Samuel , Song Tangqiumei Maggie , Mizuno Fuminori , Takechi Kensuke , Brennecke Joan F 
Published: February 2020

Owing to its extreme high theoretical energy density1, the non-aqueous Li-air battery has received remarkable attention in recent years as a promising candidate for electric vehicle applications. Ionic Liquids (ILs), molten salts that are liquid at room temperature, have been investigated as potential electrolytes in Li-air batteries due to their negligible vapor pressure, good thermal stability, and wide electrochemical windows.
However, comparing to conventional organic electrolytes, for example, ethylene carbonate (EC), ILs generally have higher viscosity and consequently lower ionic conductivity and ion diffusivity. Therefore, two low viscosity ILs, [Pyrr12O1][TFSI], N-methoxyethyl-N-methyl pyrrolidinium bis(trifluoromethanesulfonyl)imide, and [PP12O1][TFSI], N-methoxyethyl-N-methyl piperidinium bis(trifluoromethanesulfonyl)imide, and their mixture with Li[TFSI], were investigated.
In this work, the diffusivity of the cation and anion of the IL, as well as the diffusivity of the Li+ cation, were measured with pulsed-field-gradient spin-echo (PFG-SE) NMR Spectroscopy. In addition, the I-V performances of the two ILs were characterized in a Li-O2 battery and compared with a non-ether-functionalized IL, [PP13][TFSI]2. Physical properties of the ILs and IL-Li[TFSI] mixtures, including densities, viscosities, ionic conductivities, and electrochemical windows are reported. An additional property that can affect Li-O2 battery performance, the solubility of O2 in the ILs and IL-Li[TFSI] mixtures, was also measured, using a gravimetric microbalance.

References

[1] Cho, J. (2015). Metal–Air and Redox Flow Batteries. ChemPlusChem, 80(2), 257-258.

[2] Nakamoto, H., Suzuki, Y., Shiotsuki, T., Mizuno, F., Higashi, S., Takechi, K., Asaokab, T., Nishikooria, H.,& Iba, H. (2013). Ether-functionalized ionic liquid electrolytes for lithium-air batteries. Journal of Power Sources, 243, 19-23.

Figure 1
An Ionic Liquid Consisting of Crown Ether – Coordinated Hydronium Cation and Amide Anion
Authors: Takeoka Shun , Kitada Atsushi , Fukami Kazuhiro , Murase Kuniaki 
Published: February 2020

There are reports on ionic liquids (ILs) with strongly Lewis-acidic metal cations such as Li+ and K+ coordinated by ether-ligands to decrease charge density [1-2]. Crown ether 18-crown-6 (18C6) has a suitable cavity for encapsulation of K+ and hydronium ion (H3O+) [3-4]. Various compounds with H3O+ encapsulated by 18C6 ligand ([H3O+·18C6] cation) have been reported, the counteranions of which are such as hexafluorophosphate (PF6
–), tetrafluoroborate (BF4
–) and trifluoromethanesulfonate (TfO–; Tf = CF3SO2) ions [3-4]. However, their melting point are higher than 100 °C. Furthermore, as far as we know, nothing has been reported on [H3O+·18C6] complexes using bis(trifluoromethylsulfonyl)amide (Tf2N–) anion. Here, we report ILs that consist of [H3O+·18C6] cation or [H3O+· dicyclohexyl-18C6 (Dh18C6)] cation and an amide anion.
The IL comprised of [H3O+·18C6] cation or [H3O+·Dh18C6] cation and Tf2N– anion was synthesized by adding equimolar amount of 18C6 or Dh18C6 and HTf2N in water, followed by vacuum-drying. In the obtained samples, a characteristic infrared band appeared at 2200 cm–1 that was not observed in pure 18C6, was attributable to the first harmonic of symmetric bending mode (Figure 1) [5]. The H2O content of the 18C6 complex and the Dh18C6 complex was estimated to be 3.29 wt% and 2.61 wt% from Karl-Fischer titration, in good agreement with the ideal value (3.20 wt% and 2.68 wt%). From elemental analysis, infrared spectra and Karl-Fischer titration, the composition of the obtained complexes were concluded as [H3O+·18C6][Tf2N–] and [H3O+·Dh18C6][Tf2N–] (Figure 2).
1H NMR spectrum of [H3O+·18C6][Tf2N–] contained a sharp singlet near 11 ppm, characteristic of H3O+ encapsulated by 18C6. The melting point of [H3O+·18C6][Tf2N–] was 66–68 °C and [H3O+·Dh18C6][Tf2N–] was a yellowish transparent liquid at room temperature (RT) (Figure 3). At 70 °C, the viscosity and conductivity of [H3O+·18C6][Tf2N–] were 39.5 mPa s and 1.9 mS cm–1, while those of [H3O+·Dh18C6][Tf2N–] were 33.8 mPa s and 1.4 mS cm–1. In linear sweep voltammetry, potential for hydrogen production by [H3O+·18C6][Tf2N–] was similar to those of general protic liquids. The crown ether-coordinated hydronium amide IL may have potential application as electrolyte materials toward a new class of fuel cells.
[1] T. Tamura et al., Chem. Lett., 39, 753 (2010).
[2] Y. Song, H. Jing, B. Li, and D. Bai, Chem. Eur. J., 17, 8731 (2011).
[3] R. Chénevert et al., Can. J. Chem., 60, 853 (1982).
[4] G. S. Heo and R. A. Bartsch, J. Org. Chem., 47, 3557 (1982).
[5] R. Chénevert et al., Can. J. Chem., 62, 2293 (1984).

Figure 1
Solubility of Calcium and Zirconium Oxides in Melts CaO-(CaCl2-MCl)eut and CaO-CaCl2-MCl (M - Li, Na, K)
Authors: Savchuk Ruslan N , Gritsai Larisa V. , Omel'chuk Anatolii A 
Published: February 2020

This paper presents results of a study of the solubility of calcium and zirconium oxides in melts corresponding to polythermal sections CaO – (CaCl2 – MCl)eut of ternary systems CaO – CaCl2 – MCl (where M is Li, Na or K). The liquidus temperatures of the studied areas of the polythermal sections are given in Table 1.
Table 1. Composition and crystallization temperature of the investigated areas of polyttermal sections.

CaCl2(42.0) –LiCl(58.0)
CaCl2(25.7) –KCl(74.3)

Temperature, K
CaO Content
Temperature, K
CaO Content

wt. %
mol. %
wt. %
mol. %

768
1.0
2.6
903
0.5
1.64

773
5.0
11.9
933
1.0
3.17

783
11.0
23.1
963
1.5
4.72

923
13.0
26.1
1023
2.0
6.18

1023
15.0
29.1

The interaction of calcium oxide with molten CaCl2–LiCl is accompanied by the formation of calcium oxychloride compounds [CaOCln](n-2)–. But such compounds are not detected in the products of fusion of CaO with the eutectic melt CaCl2–KCl. Compared with calcium oxide, zirconia is much less soluble in the investigated melts. This difference in behavior can be explained by the different nature of the bond of the metal ions to oxygen anions and the acid-base properties of the melt-solvent. At sufficiently high temperatures, the solubility of CaO, ZrO2 is the higher, the higher the acid strength of the melt-solvent. Chlorides or oxychlorides of zirconium in the melt samples were not found after saturation with zirconia. This suggests that zirconia dissolves by a physical mechanism by the incorporation of ZrO2 molecules in the free volume of the solvent melt. The dependence of the solubility of zirconium dioxide on temperature in melts-solvents of different composition is satisfactorily approximated by the linear equation lnS = A – B/T (Table 2.).
Table 2: Values of the coefficients A and B of the temperature dependence of the solubility of zirconia in oxide–chloride melts of different cationic composition

Melt, mol .%
Coefficients of equation lnS = A – B/T

A

B

CaO(5.0) – {CaCl2 – LiCl}eut
.(95.0)
29.90
–31463.16

CaO(5.0) – {CaCl2 – NaCl}eut
.(95.0)
11.30
–11189.44

CaO(5.0) – {CaCl2 – KCl}eut
.(95.0)
11.50
–13134.50

The obtained results can be used to select the conditions for the electrolytic reduction of zirconium dioxide by the Fray – Farthing – Chen (FFC) Cambridge Process.
Electrochemical Reaction of Bis(acetylacetonato)Palladium in an Amide-Type Ionic Liquid
Authors: Yoshii Kazuki , Oshino Yosuke , Tachikawa Naoki , Toshima Kazunobu , Katayama Yasushi 
Published: February 2020

Palladium is well known as a useful metal for such as catalytic reaction, hydrogen absorption and improvement of corrosion resistance. Although the electrochemical reaction and deposition of palladium has been researched in some ionic liquids so far, the palladium sources have been limited to halogeno complexes such as [PdBr4]2− or [PdCl4]2−.1,2 We have already reported electrodeposition of Pd from 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA) containing bis(acetylacetonato)palladium (Pd(acac)2).3 In the present study, the electrochemical reaction of Pd(acac)2in BMPTFSA was investigated using a rotating ring-disk electrode.
BMPTFSA was prepared by metathesis reaction of LiTFSA and BMPBr, which was synthesized by quaternization reaction of 1-methylpyrrolidinium with n-butyl bromide in acetonitrile, followed by recrystallization with ethyl acetate. Pd(acac)2 was used as received. Electrochemical measurements were conducted in a glovebox of dry Ar atmosphere. A ring-disk electrode (Pt ring: 1.2 cm2; Pt disk: 0.79 cm2) was used as a working electrode. A Pt wire was used for a counter electrode. A silver wire immersed in BMPTFSA containing 0.1 M AgCF3SO3was used as a reference electrode. The counter electrode was separately set from the working and reference electrode by a glass filter.
The UV-vis spectrum of BMPTFSA containing 0.25 mM Pd(acac)2 was well accorded with that of ethanol solution, suggesting that Pd(acac)2 exists as a tetra-coordinated Pd complex coordinated by the oxygen atoms of acetylacetonate in BMPTFSA. The deposition of metallic palladium was confirmed on the electrode after the potentiostatic cathodic redction at −1.9 V. An anodic current was observed at the ring electrode kept at −1.25 V when the cathodic current corresponding to reduction of Pd(acac)2 was observed on the disk electrode at the potentials more positive than –1.9 V. It has been reported that some intermediate species were detected by polarogram in N, N-dimethylformamide solution containing Pd(acac)2.4 The obtained result indicated that the intermediate species, [Pd(acac)2]−, also formed by the reduction of Pd(acac)2 in this study. Thus, it is considered that the metallic palladium may be formed by the disproportionation reaction of [Pd(acac)2]−.
Acknowledgments
Part of this study was financially supported by MEXT-Supported Program for the Strategic Research Foundation at Private Universities, 2012–2016.
References
1. Y. Bando, Y. Katayama, and T. Miura, Electrochim. Acta, 53, 87 (2007).
2. I.-W. Sun and C. L. Hussey, J. Electroanal. Chem., 274, 325 (1989).
3. K. Yoshii, Y. Oshino, N. Tachikawa, K. Toshima, and Y. Katayama, Electrochem. Commun., 52, 21 (2015).
4. M. Hirota and S. Fujiwara, Bull. Chem. Soc. Jpn., 48, 2825 (1975).
Electrochemical Behavior of Samarium in Molten LiCl-KCl
Authors: Singh Vickram , Chidambaram Dev 
Published: February 2020

The mass transport behavior of samarium was investigated in molten eutectic LiCl-KCl in order to develop real-time concentration monitoring capabilities for the pyrochemical reprocessing of used nuclear fuel. Pyrochemical reprocessing relies on electrolysis in molten LiCl-KCl to recycle fissile material from used nuclear fuel. Without the capabilities to monitor concentrations of various actinides and fission products, pyrochemical reprocessing cannot be commercialized due to strict material accountability requirements set by the International Atomic Energy Agency (IAEA) [1]. Therefore, physical electrochemical properties of these species in molten salts is extremely important. Cyclic voltammetry was utilized to investigate electrochemical behavior of samarium in LiCl-KCl. By establishing valid relationships between these parameters and the peak current, the diffusion coefficient of samarium in our system can be reported with confidence [2]. Experiments were conducted in a high-purity argon atmosphere glove box using a three-electrode cell contained in an alumina crucible inside a resistive furnace. A high-resolution translation stage equipped with ceramic electrode mounts was used to accurately control electrode positions inside the melt. Tungsten was used as the counter and working electrodes, and a silver wire was used as a quasi-reference (Ag|AgCl2). The variation in peak current that resulted from changing the concentration, scan rate and electrode surface area will be reported, along with calculated diffusion coefficient values for samarium in molten LiCl-KCl at 500°C. The effects of using molybdenum as a working electrode will also be reported and compared to results obtained using tungsten. A comparison between reported diffusion coefficient values obtained by separate research organizations and results obtained in these studies will also be discussed.
Acknowledgements: This work was performed under the auspices of the Department of Energy (DOE) under contracts DE-NE0008262 and DE-NE0008236 as well as the US Nuclear Regulatory Commission (USNRC) under contracts NRCHQ-11-G-38-0039. Dr. Kenny Osborne serves as the program manager for the DOE award and Ms. Nancy Hebron-Isreal serves as the grants program officer for the NRC awards.
References
1. Iizuka, M., et al., Application of normal pulse voltammetry to on-line monitoring of actinide concentrations in molten salt electrolyte. Journal of Nuclear Materials, 2001. 297(1): p. 43-51.
2. Tylka, M.M., et al., Method Development for Quantitative Analysis of Actinides in Molten Salts. Journal of The Electrochemical Society, 2015. 162(9): p. H625-H633.
(Invited) Ion Diffusion in Ionic Liquids: Effects of Electric Fields
Authors: Welton Tom , Edel Joshua B , Ivanov Aleksandar , Kuimova Marina K , McIntosh Alastair J.S. , Nawawi Mohd A. B. 
Published: February 2020

An ionic liquid is an ionic substance in which its constituent ions are in motion. Consequently, it is not possible to understand the nature of an ionic liquid without understanding how its constituent ions move. However, gaining a thorough understanding the nature of ion motion in ionic liquids remains a fundamental challenge.
Single molecule fluorescence (SMF) confocal spectroscopy offers a powerful, but as yet largely underutilized tool to measure the diffusion of probe ions in an ionic liquid under a variety of conditions.
To enable SMF measurements, it was necessary to develop the synthesis of ionic liquids with very low background fluorescence. The SMF derived diffusivity of the cationic probe dyes in dilute (ca. 100 pM) solutions in [C4C1im][NTf2] and [C4C1pyrr][NTf2] solutions was compared to diffusivity of the ionic liquid cations derived from Pulse Gradient Stimulated Echo NMR measurements. The SMF derived diffusivities of the cationic probes were measured under various applied potentials and throughout the system’s relaxation back to its unperturbed state. This relaxation was found to be markedly slower than in salt solutions in molecular solvents. These results were compared to measurements of microscopic viscosity using the fluorescence spectra of molecular rotors.
Electrodeposition of ZnNi Alloys from Ethylene Glycol/Choline Chloride Based Ionic Liquid
Authors: Panzeri Gabriele , Tresoldi Matteo , Nobili Luca , Magagnin Luca 
Published: February 2020

Zinc alloys containing transition metals (Ni, Co and Fe) have attracted the attention because of their high corrosion resistance [1,2]; particularly high is the interest of ZnNi system for practical application. In addition, electrodeposition of ZnNi alloys is generally described as anomalous codeposition (Brenner [3]). In this work ZnNi electrodeposition from ionic liquid system is studied; particular attention is paid to the formation Zn rich alloys (15-25 % Ni). The plating bath consists of 1 choline chloride: 2 ethylene glycol containing metal salts in different concentration. All the electrodepositions have been carried out at constant temperature T=70°C on steel. Codeposition of ZnNi is studied by means of potentiostatic electrodeposition. Compositional and morphological analysis are performed to evaluate the effect of the plating conditions and bath formulation. Electrochemical characterization of the solution is performed for those baths compositions allowing the formation of 𝛾-phase ZnNi. Metastable 𝛾-ZnNi with short-range order has been observed with XRD analysis; thermal treatment are carried out to evaluate phase reorganization.
[1] R Fratesi, G Roventi. Corrosion resistance of Zn-Ni alloy coatings in industrial production, Surface and Coatings Technology. 82 (1996) 158.
[2] R Ramanauskas, P Quintana, L Maldonado, R Pomés, MA Pech-Canul. Corrosion resistance and microstructure of electrodeposited Zn and Zn alloy coatings, Surface and Coatings Technology. 92 (1997) 16.
[3] A Brenner. A. Electrodeposition of Alloys. Vol. 1, General Survey, Principals, and Alloys of Copper and of Silver, (1963).
Natural Fiber Welding of Chitin and Chitosan on a Cotton Cloth Substrate: Novel Materials Displaying Antimicrobial Properties
Authors: Russell Robert Allen , Fox Eric T , Nolan Robert , Chandler Molly , Head Audrey C. , Brusoski Michael , De Long Hugh C , Trulove Paul C 
Published: February 2020

Ionic liquids (ILs) can be used as solvents for biopolymers due to unique chemical and physical properties that enable mobilization and disruption of the hydrogen bonding present in the biopolymer structure. Chitin and chitosan are biopolymer known to have natural antimicrobial properties. The goal of this work is to functionalize a composite cotton yarn or cloth with a chitin or chitosan biopolymer, in order to exploit the bio-active properties of chitin or chitosan, while maintaining the intrinsic physical and chemical properties of cotton yarn. We will be using a method called Natural Fiber Welding (NFW) to incorporate chitin or chitosan biopolymers into cotton materials.
Natural Fiber Welding is the process of full or partial dissolution of a substrate and the regeneration using ILs, such as 1-ethyl-3-methylimidazolium acetate. Using this process, chitin or chitosan is able to be permanently adhered and chemically bonded to the outer and inner surface of the native yarn. Changing factors, such as ionic liquid solution composition (introducing DMSO), temperature, time, and concentration of biopolymers alters the degree of biopolymer mobilization which influences what properties the composite yarn displays. In this study we will show results for chitin or chitosan welded into cotton composite materials. We will present data characterizing the physical, chemical, and biochemical properties of these composites. Data from confocal fluorescence microscopy (CFM), SEM imaging, and Bactericidal Killing Assays will be shown using E.Coli transfected with Green Fluorescent Protein. In conclusion, it appears that we can effectively coat and integrate chitin or chitosan onto the cotton material and the material exhibits antimicrobial properties.
the Enhanced Electrocatalytic Activity over Carbon-Supported Pd-Based Ordered Intermetallic Compounds
Authors: Gunji Takao , Tanabe Toyokazu , Kaneko Shingo , Ohsaka Takeo , Matsumoto Futoshi 
Published: February 2020

In recent years, the direct fuel cells (DFCs) have attracted increasing interest as next energy device in the area of polymer electrolyte membrane fuel cells due to its high efficiency and high power density. Formic acid (FA) has been receiving paramount attention as fuel for DFCs because of its high energy density (1740 Wh kg-1, 2086 Wh L-1) and fuel crossover of FA is smaller than that MeOH [1]. In addition, the electrooxidation current density (and mass activity) of FA over Palladium (Pd) nanoparticles (NPs) is higher than that Platinum (Pt) electrocatalyst [2]. Therefore, the DFCs, which FA is used as fuel, can be operated without Pt electrocatalyst. However, electrocatalytic activity towards electrooxidation of FA is still in need of improvements.
In order to enhance electrocatalytic activity towards electrooxidation of FA, Pb was used as secondary material for alloying with Pt because of CO-poisoning tolerance of electrocatalysts. Recently, we have previously reported that ordered intermetallic PtPb efficiently electrochemically catalzed for electrooxidation of FA, MeOH and EtOH [3]. In particular, core shell structure of bimetallic Pt3Pb exhibited efficient electrocatalytic activity for the electrochemical oxidation of FA, MeOH and EtOH. These indicate that Pb atom in ordered intermetallic PtPb (and/or bimetallic Pt3Pb) facilitates more efficiency of FA electrooxidation not only enhancement of electrocatalytic activity but also CO-poisoning tolerance.
This study demonstrates the new approach in preparation of carbon supported ordered intermetallic Pd3Pb NPs (Pd3Pb NPs/CB), which has a Cu3Au type structure, via polyol method under air atmospheric air without anneal treatment. In addition, Pb atom in ordered intermetallic Pd3Pb NPs were dissolved under acidic environment by cyclic voltammetry up to 1.1 V, resulting in formed surface-dealloyed Pd-shell ordered intermetallic Pd3Pb core structure (Pd@Pd3Pb NPs/CB). The surface of prepared Pd@Pd3Pb NPs/CB was characterized by using XPS and HR-TEM. The electrochemical activity of prepared Pd@Pd3Pb NPs/CB is compared to commercially available Pt NPs/CB, PtRu NPs/CB and Pd NPs/CB. In addition, electrochemically surface-dealloyed Pd@Pd3Pb NPs/CB has better catalytic activity towards the electrooxidation of FA than other electrocatalysts.
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2015, 273, 990.