bluuebunny/crossref_metadata_2025_split huggingface dataset:
Visible Light-Driven Cross Coupling Reactions Catalyzed By B12 Complex with Photosensitizer
Authors: Shimakoshi Hisashi , Chen Li , Hisaeda Yoshio , Anai Yuki 
Published: February 2020

Organometallic B12 compounds are unique metal complexes having a cobalt-carbon σ-bond present in biological systems [1]. Cleavage of the metal-organic σ-bond initiates many B12-dependent enzymatic reactions. The alkylated cobalt complex is generally formed by the reaction of the Co(I) state of the complex with electrophiles such as an organic halide in vivo. Therefore, the reductive formation of the Co(I) species followed by formal oxidative addition of the organic halide to form the alkylated cobalt complex are key steps for the development of the B12 catalyzed enzymatic reactions. Our group has been reported the photosensitizing formation of the Co(I) species of the B12 derivative, heptamethyl cobyrinate perchlorate, using various photosensitizers (PSs) such as, [Ru(bpy)3]Cl2 or cyclometalated iridium(III) complexes and performed various B12 model reactions such as 1,2-migration of functional groups, dechlorination and so on [2,3]. Here, a visible light driven Heck-type coupling reaction of alkyl halides with styrene and its derivatives catalyzed by the cobalamin derivative (B12) with the [Ru(bpy)3]Cl2 photosensitizer at room temperature is reported. The catalytic efficiencies of the B12 catalyst were compared to that of other cobalt complexes such as cobaloxime. Various control experiments supported a radical-based mechanism similar to those for typical B12 model reactions. An unique coupling reaction combined with 1,2-migration of the functional group is also reported. Mild reaction conditions using an environmentally benign cobalt catalyst derived from the natural B12 provided a practical protocol for the synthetic organic chemistry of the B12 catalyzed reaction system.
[1] Reviews: a) H. Shimakoshi, Y. Hisaeda, Current Opinion in Electrochem. 2018, 8, 24; b) H. Shimakoshi, Y. Hisaeda, ChemPlusChem. 2017, 82, 17 (Back cover).
[2] H. Tian, H. Shimakoshi, T. Ono, Y. Hisaeda, ChemPlusChem
2019, in press (Front cover).
[3] H. Shimakoshi, Y. You, Y. Hisaeda et al, Dalton Trans. 2018, 47, 675 (Front cover).
Ethanol Production from Saccharum Spontanum Biomass Native to Nepal Using Bioelectrochemical Cell
Authors: Joshi Jarina 
Published: February 2020

Bioethanol can be used as an octane enhancer and alternative replacement to blend with petroleum fuels. Using an electrochemical cell for the production of bioethanol facilitates the enhancement in ethanol production exploiting the electrochemical redox reactions occuring inside the cell. The externally supplied voltage is used to drive the chemical reactions to generate the metabolite, i.e; ethanol. A microbial electrochemical cell was designed with porous carbon fiber coated with neutral red as cathode and platinum wire coated with fine platinum as anode. Saccharum spontanum biomass pretreated with hot water at 100oC for 2 hours followed by acid hydrolysis was neutralized and used for production of ethanol by Saccharomyces cereviseae in electrochemical cell. A total supply of 4V was found to be best for maximum ethanol production in 300 ml fermentation volume.
Key words: ethanol, microbial electrochemical cell, voltage.
Electrochemically Stable and Adherent PEDOT Coatings for High Quality EMG Recording
Authors: Rossetti Nicolò , Luthra Prabhjot , Lee Ada , Bodart Leguen Come , Cicoira Fabio 
Published: February 2020

Conductive polymers coatings on metal electrodes are an efficient solution to improve neural signal recording and stimulation due to their mixed electronic-ionic conduction and biocompatibility [1]. However, only a few studies have been reported on conductive polymers coatings on metallic wire electrodes for muscle signal recording [2,3]. In this work, we developed mechanically and electrochemically stable invasive electrodes for muscle signal recording in small animals based on stainless steel multi-stranded wires coated with the conductive polymer PEDOT.
PEDOT doped with LiClO4 was galvanostatically electropolymerized on stainless steel wires using three different solvents: propylene carbonate (organic), acetonitrile (organic) and water (inorganic). The coatings adhesion to the metallic substrate was tested through ultrasonication and the electrochemical stability was evaluated through phosphate buffer solution soaking test and autoclave sterilization.
The solvent played a key role on the adhesion of the PEDOT coating, with organic solvents giving the best mechanical stability. Electrodes prepared with these solvents possessed excellent electrochemical stability and survived sterilization and prolonged soaking without major changes in electrochemical properties.
A solution for high quality invasive muscle signal recording in small animals based on conductive polymers has been demonstrated.
References
[1] R. Balint, N. J. Cassidy, and S. H. Cartmell, "Conductive polymers: Towards a smart biomaterial for tissue engineering," Acta Biomaterialia, vol. 10, no. 6, pp. 2341-2353, 2014.
[2] S. Kim, L. K. Jang, M. Jang, S. Lee, J. G. Hardy, and J. Y. Lee, "Electrically Conductive Polydopamine–Polypyrrole as High Performance Biomaterials for Cell Stimulation in Vitro and Electrical Signal Recording in Vivo," ACS Applied Materials & Interfaces, vol. 10, no. 39, pp. 33032-33042, 2018.
[3] H.-C. Tian et al., "Enhanced Flexible Tubular Microelectrode with Conducting Polymer for Multi-Functional Implantable Tissue-Machine Interface," Scientific Reports, Article vol. 6, p. 26910, 2016.
Monolayer Effects on Surface Plasmon Resonance of Au Thin Films
Authors: Artur Camille , Yarali Miad , Ahmadi Kamyar , Shan Xiaonan , Brankovic Stanko 
Published: February 2020

Surface plasmons (SP’s) or surface plasmon polaritons are longitudinal electromagnetic waves which propagate at the interface between a metal and a dielectric. They are localized in the interface and are sensitive to the optical properties of the materials comprising the interfacial region. As such, the SP present a unique probe to study the electrochemical interface and double layer [[1],[2]].Typical plasmonic metals/electrodes are Au and Ag thin films, which have been a subject of studies where the SPs have been used to probe the electrochemical processes such as adsorption and underpotential deposition [1,[3],[4]]. The most recent developments indicate that the SPs can be used to enhance certain electro-catalytic and photocatalytic reactions [[5]].
In this report, we present the results investigating the catalyst monolayer modification effect on plasmon resonance of Au thin films. The experiments are conducted using an attenuated total reflection arrangement in which p-polarized light is incident through a prism onto a thin (-400 A) Au film deposited on the mica substrate. (Kretschmann configuration [[6]]). The angle of incidence on the base of the prism is greater than the critical angle for the prism: electrolyte interface and SPs are excited by the evanescent wave generated under these conditions of total internal reflection. The excitation is manifested by a decrease in the intensity of reflected light. The Pd monolayer on Au were electrodeposited using procedure reported by Kolbe et al [[7],[8]], while the Pt submonolayer/monolayers were deposited on Au using Surface Limited Redox Replacement (SLRR) of Pb UPD monolayer [[9]]. The plasmon resonance frequency of Au(hkl), PdML/Au(hkl) and PtML/Au(hkl) and PtSML/Au(hkl) were investigated as a function of the applied potential in the range between -0.24 V to 0.4 V vs. SCE. The comparative analysis, between Au and catalyst monolayer modified Au(hkl) samples indicate that SP resonant frequency change is induced by both; surface charge and adsorption of H on the catalyst monolayer surface in the UPD region. The latter effect is quantified using subtractive analysis between the Au and catalyst modified Au surface and solutions with different pH. In conclusion, we present a simple model describing the catalyst monolayer effect on plasmon resonance of Au films.
[1] J.G. Gordon II and S. Ernst, Surface Science, 101 (1980) 499
[2] R. Kotz et al, Surface Science, 69 (1977) 359
[3] D.M. Kolb, D. Leutloff and M. Prasnyski, Surface Science, 47 (1975) 622
[4] A. Bewick, and B. Thomas, J. Electroanalytical Chem., 65 (1975) 911
[5] S. Linic, U. Aslam, C. Boerigter and M. Morabito, Nature Materials, 14, (2015) 567.
[6] E. Kretschmann and H. Raether, Z. Natutforsch. 23a (1968) 2135.
[7] L.A. Kibler, M. Kleinert, R. Randler, D.M. Kolb, Surface Science, 443 (1999) 19.
[8] J. Tang, M. Petri, L.A. Kibler, D.M. Kolb, Electrochimica Acta, 51, (2005) 125
[9] K. Sasaki et al, Electrochim. Acta, 55, (2010) 2645.
Strain Effect on Electrolytic Hydrogen Isotope Separation
Authors: Hasanzadehshirazi Mehrnaz , Dongjun Wu , Artur Camille , Grabow Lars , Brankovic Stanko 
Published: February 2020

The effect of strain in Pt and Pd monolayer catalyst is explored for electrolytic hydrogen isotope separation. Positive/negative strain increases/decreases strength of adsorbed hydrogen bond in overpotential region where recombination of hydrogen atoms is the rate determining step in hydrogen evolution reaction. As a result, the increased/decreased hydrogen isotope separation efficiency of Pt and Pd monolayers is expected as compared to bulk Pt and Pd. The positive/negative strain rises/lowers diffusion barrier for adsorbed hydrogen atoms. This effect favors/retards recombination of isotopes with smaller mass. As the surface is stretched/compressed, the neighboring adsorption sites separate/approach each other which affects heavier hydrogen isotopes more/less and results in their lower/higher probability for recombination. All these fundamental consideration indicate that Pt and Pd monolayers with different level of strain should have much different separation factors than corresponding bulk electrodes. To study described effects, Pt and Pd monolayers we synthesized electrochemically on Au(111) and Ru(0001) electrodes each yielding qualitatively different strain levels (Au-positive, Ru-negative). Pd monolayers are synthesized using electrodeposition[1] while Pt monolayers were synthesized using deposition via surface limited redox replacement reaction[2]. The adsorption strength of hydrogen isotopes is studied by infra-red spectroscopy. These results will are input in our classical models for isotope separation[3] and to our DFT calculations. The calculated ratio between the rates of hydrogen and deuterium recombination and separation factors for Pt and Pd monolayers and corresponding bulk electrodes are compared to experimentally measured ones. The following discussion is focused on understanding and quantification of strain effects on separation efficiency of Pt and Pd monolayers.
[1] H. –F. Waibel, M. Kleinert, L. A. Kibler, and D. M. Kolb, Electrochim. Acta, 47, 1461 (2002).
[2] S. R. Brankovic, J. X. Wang and R.R. Adzic, Surface Science, 474, L173 (2001).
[3] B. E. Conway, Proceedings of The Royal Society of London, A. Mathematical and Physical Sciences, 247, 400 (1958).
The Stability and the Electrochemical Properties of Na3V3+
2-Y
V4+

y
(PO4)2F3-Y
O
y
(0 ≤ y ≤ 2)
Authors: Nguyen Hoang Bao Long , Broux Thibault , Sanz Camacho Paula , Fauth François , Carlier Dany , Olchowka Jacob , Masquelier Christian , Croguennec Laurence 
Published: February 2020

Polyanionic materials are currently intensively studied as promising active materials for positive electrodes in Na-ion batteries thanks to their high stability and the fast ionic mobility within their structural framework. [1] Among those polyanionic materials, Na3V2(PO4)2F3 and Na3V2(PO4)2FO2 are the two most attractive ones due to their high voltage for two Na+ ions extraction and their high theoretical energy densities: 500 mAh.g-1 and 495 mAh.g-1, respectively. These two compositions are indeed the two end members of a family of compounds described with the general formula Na3V2(PO4)2F3-y
O
y
where 0 ≤ y ≤ 2. [2-6] We will discuss here in depth the chemical reaction used to prepare these materials, in order to understand the nature of the impurities and active compounds formed in some specific conditions, as well as the stability of these active compounds in aqueous media.
The combination of a large panel of characterization techniques reveals that the members of the Na3V2(PO4)2F3-y
O
y
family are stable in aqueous media, with no water intercalation in the channels of the structure and no Na+/H+ or F-/OH- exchange, despite of the long immersion time. These materials can thus be used for electrode formulation in aqueous media. [7] The electrochemical behavior and performance of Na3V3+
2(PO4)2F3, Na3V3+V4+(PO4)2F2O and Na3V4+
2(PO4)2FO2 will be compared for different cycling potential windows, with careful attention to their chemical stability.
References:

[1] C. Masquelier and L. Croguennec, Chem. Rev., 2013, 113, 6552–6591.
[2] R.K.B. Gover et al., Solid State Ionics 177 (2006) 1495–1500.
[3] J. Baker et al., J. Electrochem. Soc. 2004, 151 (10), 1670-1677.
[4] Y.-U. Park et al., Adv. Funct. Mater. 2014, 24 (29), 4603-4614.
[5] P. Serras et al., Chem. Mater. 2013, 25, 4917−4925.
[6] T.Broux et al., Chem. Mater. 2016, 28 (21), 7683-7692.
[7] P.R. Kumar et al., J. Mater. Chem. A, 2015, 3, 6271-6275.
Identifying the Performance Limitations of Layered Oxide Sodium-Ion Batteries Using EIS
Authors: Middlemiss Laurence Adam , Rennie Anthony J R , Sayers Ruth , West Anthony R 
Published: February 2020

Sodium-ion (Na-ion) batteries have received considerable attention in recent years as a cheaper, safer, more sustainable alternative to conventional lithium-ion (Li-ion) technology [1,2]. Battery cycle life is an important performance criterion with respect to the commercialisation of these. All batteries will experience, with time, some reduction in performance due to a variety of degradation mechanisms, some of which are linked to a rise in cell impedance [3]. Therefore, by carrying out a combination of constant-current, constant-voltage (CC/CV) cycling in combination with electrochemical impedance spectroscopy (EIS), it should be possible to identify the rate-limiting steps and problem interfaces inside a cell. Identifying such factors will make it possible to address them and therefore enhance overall battery performance.
We have applied electrochemical impedance spectroscopy (EIS) to layered oxide Na-ion cells in order to identify factors that limit cell performance. Figure 1 depicts the voltage profile for a typical cycle. These data were collected at charge and discharge rates of ~ C/10 and ~ C/5 respectively, using voltage limits of 4.2 V and 1.0 V. Figure 2 denotes a typical cycle life plot. A reversible capacity of 123 mAh/g (cathode) was retained after 100 cycles, indicating a charge retention of 98 %. Most of the capacity loss was recovered when subsequently cycled at lower rates, suggesting that this reduced capacity was due to increased cell impedance rather than an irreversible loss of Na.
EIS was performed on a range of different cell configurations, including a novel three-electrode pouch cell design. Spectra were recorded at varying states of health (SoH) and states of charge (SoC). Results were analysed by fitting ideal equivalent electrical circuits to impedance data, and using these to attribute resistances and capacitances for the different components present in the impedance response. Spectra were plotted using different complex formalisms in order to highlight different aspects of collected data, to the best of our knowledge this is an approach not previously reported in the analysis of batteries.
The cathode was found to be primarily responsible for resistive losses inside these layered oxide Na-ion cells, with the impedance associated with the positive electrode continuing to grow during cycling. Further characterisation and techniques to try and improve the performance of these sodium-ion batteries will be provided during the presentation.
References:
[1] J.W. Choi, and D. Aurbach, Nat. Rev. Mater., 2016, 1, 16013.
[2] N. Yabuuchi, K. Kubota, M. Dahbi, and S. Komaba, Chem. Rev., 2014, 114, 11636.
[3] J. Vetter, P. Novák, M. R. Wagner, C. Veit, K.-C.Möller, J. O. Besenhard, M. Winter, M. Wohlfahrt-Mehrens, C. Vogler, and A. Hammouche, J. Power Sources, 2005, 147, 269.

Figure 1
Anionic Redox in Li-Rich Rocksalt Oxides Studied Via X-Ray Photoelectron Spectroscopy
Authors: Coca Clemente Jose Antonio , Hardwick Laurence J. , Dhanak Vinod R. 
Published: February 2020

Layered LiMO2 compounds can be considered as a progressive substitution of excess Li+ for M3+ in the [MO2] layers, with a 1:1 Li:M ratio. A derivative from this type of compound corresponds to a material with the general formula of Li(Li1/3M2/3)O2. This has been alternatively described with the formula Li2MO3 (where M has been reported as Mn, Ru, Ti, Zr, Sn, Pt), and often referred to as a “Li-rich” rocksalt oxide (with Li/M > 1 and space group C2/m). Li-rich rocksalt oxides are of technological importance as cathode materials in rechargeable Li-ion batteries. Recently, the possibility of using oxygen as a redox centre in this kind of oxides has been established in the design of cathode materials with enhanced capacities (> 200 mAh/g). [1-3]
Among the numerous compounds with Li-rich Li2MO3 structure type, Li2MnO3 is the most studied so far; the combination with other transition metals such as Co and Ni can help to improve the capacity, rate capability and reduce the capacity fading.
In this work, a study of a series of Li-rich compounds with rock salt structure was synthesised with a general formula of Li1+δ(Ni1-x-yCoxMny)1-δO2 and electrochemically cycled versus lithium metal. An increase in the specific capacity compared with materials of the same family such as layered LiNi1/3Co1/3Mn1/3O2 was observed, in line with numerous reports by research groups worldwide. In this presentation, X-ray photoemission spectroscopy of O1s taken at different stages of the load curve of the Li1+δ(Ni1-x-yCoxMny)1-δO2 electrode material will be presented. The experimental evidence pertaining to the oxidation of O2- driving to the formation of peroxo-like species (O2)n− in the material and charge compensating the extraction of Li+ ions by the removal of electrons from lattice oxygen; that allows this material to have more capacity than expected will be critically discussed.

References:

[1] Saubanère, M., McCalla, E., Tarascon, J.-M. & Doublet, M.-L. The intriguing question of anionic redox in high-energy density cathodes for Li-ion batteries. Energy Environ. Sci.
9, 984–991 (2016).
[2] Seo, D.-H. et al. The structural and chemical origin of the oxygen redox activity in layered and cation-disordered Li-excess cathode materials. Nat. Chem.
8, 692–697 (2016).
[3] Perez, A. J. et al. Approaching the limits of cationic and anionic electrochemical activity with the Li-rich layered rocksalt Li3IrO4. Nat. Energy
2, 954 (2017).
(Invited) Multiscale Molecular Modeling for Polymer Electrolyte Membrane for Fuel Cell
Authors: Shinoda Wataru 
Published: February 2020

Multi-scale “molecular” modeling approach has been developed and applied to polymer electrolyte membrane. The goal of this work is to investigate the possible morphology, structure, dynamics, and mechanical properties of perfluorosulfonic acid (PFSA) membrane with realistic polymer chain lengths (>100 monomer units) by molecular dynamics (MD) simulations. First, we have carried out a series of all-atom (AA) MD simulations of PFSA polymer with a short chain length (10 monomer units) to yield reference structural data for building a coarse-grained (CG) molecular model. Although many phenomenological modeling based on dissipative particle dynamics has been proposed previously, a chemically accurate CG model should be beneficial to investigate the morphology in realistic membranes and to provide a concrete molecular design. Thus, we attempted to construct a predictive CG model for the structure and morphology of PFSA membranes that is compatible with the SDK CG water model. [1] As a first trial, we extended the parameter set in the SDK CG force field to examine a hydrated PFSA membrane based on thermodynamic and structural data from experiments and AA-MD simulations. However, a noticeable degradation of the morphology was detected, which motivated us to improve the structural properties by a combination with the iterative Boltzmann inversion (IBI) approach. The hybrid SDK/IBI model was determined to reasonably reproduce both the thermodynamic and structural properties of the PFSA membrane for all examined water contents. [2] In addition, the obtained CG model demonstrated good transferability. Then, we used the CG-MD to simulate realistic long-chained (including more than 120 monomer units) PFSA membranes. We obtained successfully a well converged structure for this long-chained membrane system. We also developed a reverse-mapping method and successfully used it to produce a well-equilibrated structure at all-atom resolution. We further investigated the mechanical properties of this realistic PSFA membranes at AA resolution. The uniaxial tension tests were conducted to understand the mechanical behavior of hydrated PEM membranes, especially the failure mechanism of the membranes. It was observed that the results (Poisson's ratio, free volume) of the uniaxial deformation were sensitive to the hydration level. This computational methodology will provide more chemically realistic predictions of the PEM membrane properties and give an insight into how to develop the large-scale atomistic PEM model in a multi-scale framework. We will further discuss the effect of equivalent weight (EW) and side chain length on morphology and dynamics of PFSA membranes.[3,4]
[1] Shinoda et al., Mol. Simul.
33, 27 (2007).
[2] Kuo et al., J. Chem. Phys. 147, 094904 (2017).
[3] Kuo et al., J. Phys. Chem. C 120, 25832 (2016).
[4] Kuo et al., Polymer, 146, 53 (2018).
Formation of Small Polaron and Polaronic Charge Transfer within BiVO4 Photocatalyst
Authors: Sarker Hori Pada , Huda Mohammad Nurul 
Published: February 2020

Harnessing the power of solar energy plays an essential role in developing renewable energy technologies to supplement or perhaps replace fossil fuel utilization. The green energy technology has the potential to address the challenges of growing energy demand and climate changes around the world. Production of H2 from water splitting via photo-electrochemical process is one of the potential green technologies. BiVO4 is one of the best photoanode material for water oxidation as well as photo-catalyst for H2 evolution via water splitting. Despite being an efficient photo absorber material, it has poor charge transport properties. It is anticipated that some of the conduction electrons get bind to specific lattice sites and form polarons, and hence, the charge transfer within this material happens via the polaron hopping from one lattice site to another. In this present study, we have studied the polaron formation at cationic lattice sites and calculated the site to site polaron hopping barrier along a specific hopping pathway in the framework of density functional theory (DFT) with the Hubbard parameter U for self-energy correction of localized d electrons. Finally, the polaron transfer rate, mobility, and diffusion coefficient will also be presented.
The work of MNH is supported by NSF grant #1609811. We also acknowledge the computational time from Texas Advanced Computing Center (TACC).