bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Electrochemistry in Plasmas: From Flames to RF Plasma Jets
Authors: Caruana Daren , Sener M Emre , Calleja Maria , Elahi Atif 
Published: May 2020

As electrochemists, we are interested in electron attachment and detachment processes. Traditionally, we control the availability of electrons via an electrically conducting solid and measure electron transfer across the solid/liquid interface. Of course, there are exceptions to this picture, e.g. liquid/liquid interfaces, but often liquids are involved to provide an electrolyte medium to support the chemical species. Gaseous electrolytes have typically been ignored due to their feeble electrical conductivity. However, recently with the advent of new accessible approaches to form stable plasmas, these electrically conducting gases are attracting some significant interest and are now being investigated as exotic electrochemical environments.
The defining property of plasmas is presence of free electrons; because of this they may be considered as both electrodes or electrolytes1, 2. We describe results supporting both modes.
As electrodes, we show that metal oxides on surfaces may be reduced to zero valent metals using a helium atmospheric plasma jet.3 We show that free electrons do indeed reduce a copper oxide film, which may be carefully controlled by surface bias.4

A gaseous flame doped with electroactive species may be considered as electrolytes. Using a three-electrode system5, we may measure unique voltammograms for a series of small organic molecules and amino acids.6 Except for leucine and isoleucine, all were distinguishable. The reduction signatures originate from specific electron attachment reactions of radicals formed via incomplete combustion and fragmentation of the parent molecules. In this case without a solvent we have an extended potential window and our voltammograms extend between 0 and -10 V, which gives unprecedented access to chemistry not previously accessible in liquids. Moreover, mass transport properties are far better than in liquids, as such the fluxes of electroactive species to the electrode a much greater.

References

1. Rumbach, P., Bartels, D.M., Sankaran, R.M. & Go, D.B. The solvation of electrons by an atmospheric-pressure plasma (vol 6, pg 7248, 2015). Nature Communications
7 (2016).
2. Elahi, A., Fowowe, T. & Caruana, D.J. Dynamic Electrochemistry in Flame Plasma Electrolyte. Angewandte Chemie-International Edition
51, 6350-6355 (2012).
3. M. Emre Sener, S.S., Robert Palgrave, Raul Quesada Cabrera, Daren J. Caruana Patterning of Metal Oxide thin Films using H2/He Atmospheric Pressure Plasma Jet. Green Chemistry
Submitted (2019).
4. Sener, M.E. & Caruana, D.J. Modulation of copper(I) oxide reduction/oxidation in atmospheric pressure plasma jet. Electrochemistry Communications
95, 38-42 (2018).
5. Fowowe, T., Hadzifejzovic, E., Hu, J.P., Foord, J.S. & Caruana, D.J. Plasma Electrochemistry: Development of a Reference Electrode Material for High Temperature Plasma. Advanced Materials
24, 6305-6309 (2012).
6. Calleja, M., Elahi, A. & Caruana, D.J. Gas phase electrochemical analysis of amino acids and their fragments. Communications Chemistry
1 (2018).
Effect of Plasma-Activated Zinc Oxide Surface on Liquid Stability
Authors: Stražar Petra , Zavašnik Janez , Likozar Blaž , Cvelbar Uros 
Published: May 2020

The ZnO is an essential material in material science, agriculture, food industry, cosmetics, medicine etc. Most applications exploit ZnO physicochemical properties such as optical, electrical, mechanical and thermal. In material science, ZnO is commonly used in gas sensors, light-emitting diodes, field-effect transistors, UV lasers, photodetectors, solar cells, photo and heterogeneous catalysis. The ZnO characteristics for different applications can be controlled by size and morphology of particles with numerous techniques.
In this work, we study the effect of UV light and plasma treatment on ZnO surface morphology, crystallography and effect on its other intrinsic properties. For study, the UV-A/C light is used and compared to atmospheric pressure plasma generated in Ar or He as well as low-pressure RF – ICP plasma generated in oxygen gas. The research is focused on how UV or other plasma related changes influence the material intrinsic properties and change stability of liquid organic compounds in low ppm concentrations. The resulting interaction between stable liquid and modified material namely result in creation of other unstable molecules and compounds as well as reactive species. This approach enables improved design of catalytic performance of nanomaterials by designing their surface properties by plasma, beyond mere enhancement of surface area. The targeted liquids for modifications are thiophens in organic solvents, where we need to look at interactions of this liquids with material. To unravel these interactions, various analyses are used including UV-Vis, HPLC, and NMR. Further for surface characterisation of materials, the analyses including XPS, FTIR, UV-Vis, BET, SEM and TEM are used. The obtained results give then systematic explanation, how UV or plasma changes of material intrinsic properties translate into targeted liquid interactions and modifications.
(Invited) Nitrogen Fixation Using Non Thermal Atmospheric Plasma (over water): Challenges and Perspectives on Nitrogen Fixation Using Non Thermal Atmospheric Plasma (over water): Challenges and Perspectives
Authors: Maira Nicolas , Remy Antoine , Roy Nepal Chandra , Pattyn Cédric , Reniers François 
Published: May 2020

Nitrogen fixation, i.e. the transformation of molecular nitrogen into nitrates or ammonia is a major industrial process. The Haber-Bosch and the Ostwald processes are at the origin of the massive increase of yield of food production, contributing to the development of modern agriculture. However, despite the fact that these processes are exothermic, the need to operate at high temperature for kinetic reasons, the necessity to start (most often) from natural gas as a source of hydrogen, and the industrial plants located far away from the end user, make these industrial processes huge producers of CO2.
Historically, the Birkeland-Eyde process, however, allow to fix nitrogen using arc plasma. The energy yield of this process being small, it was replaced by the Haber-Bosch process. With the development of low temperature, non thermal plasmas processes, there is nowadays a hope to develop local, low energy cost, nitrogen fixation reactors, with only air as reactant. For food and agriculture applications, especially for urban agriculture, a possible approach is to generate nitrates directly inside the water that feeds the plants. The talk will present a few non thermal atmospheric plasma setups than can be used for nitrogen fixation. In a first setup, nitrogen oxides are generated directly in a dielectric barrier discharge (DBD) filled with various proportions of nitrogen and oxygen. In a second setup, one of the dielectrics is replaced by water. In a third setup, a DC microplasma is lighted up between a metallic electrode and a water solution, containing an electrolyte. In this last setup, a counter electrode closes the electrical circuit, making it resembling a electrochemical cell. In this last setup, two configurations are tested, by changing the polarity of the two electrodes.
For all the setups, the amount of various nitrogen oxides formed in the gas phase as a function of the experimental parameters is studied using optical emission spectrometry, infrared spectrometry and mass spectrometry. Similarly, the composition of the liquid phase is analyzed using ionic chromatography and specific reagents tests. Correlations between a) the gas phase composition and b) the liquid phase composition are established. The role of OH radicals (in the gas phase) and hydrogen peroxide (in the liquid phase) on the relative amounts of nitrites and nitrates is evidenced. For the microplasma experiments, it is shown that inverting the polarity of the electrodes lead to drastic changes in the yields of the species produced. From all these results, potential mechanisms will be presented, and future challenges will be open to discussion.
Effect of Cation Substitution on the Sodium Ionic Conductivity of Nasicon-Type Solid Electrolyte
Authors: Yang Chun-Chi , Chen Han-Yi 
Published: May 2020

The invention of secondary batteries technology is a milestone in the electronic industry. However, the liquid organic electrolytes suffer from safety issues such as flammability and explosion. This give rise to the progress of new solid electrolytes as non-flammable alternatives. Another obstacle that prevents all-solid-state electrolytes from practical use is the high contact resistance between electrode and electrolyte which results in low ionic conductivity. Therefore, our study aims to develop a chemically stable sodium solid electrolyte with high ionic conductivity at room temperature.
In this study, we modified a NAISCON-type sodium ionic solid electrolyte by cation substitution. By using NASICON/polymer film, we reduced the contact resistance between electrolyte and electrodes. The modified materials were analyzed by scanning electron microscopy, X-ray diffraction analysis, and electrochemical impedance spectroscopy measurements. An ionic conductivity up to 10-4 S cm-1 at room temperature was obtained. The modified NASICON-type sodium ionic solid electrolyte was then assembled into a full-cell system to demonstrate its applications in all-solid-state sodium ion batteries.

Keywords: solid electrolytes, polymer film
Very High Lithium Diffusion in LiTi2(PS4)3 through Energy Landscape Frustration
Authors: Hautier Geoffroy , Di Stefano Davide , Miglio Anna , Robeyns Koen , Filinchuk Yaroslav , Lechartier Marine , Senyshyn Anatolyi , Ishida Hiroyuki , Spannenberger Stefan , Roling Bernard , Prutsch Denise , Rettenwander Daniel , Wilkening Martin , Kato Yuki 
Published: May 2020

Solid-state materials with fast high ionic diffusion are necessary to many technologies including all-solid-state Li-ion batteries.
Here, we demonstrate that LiTi2(PS4)3 (LTPS) exhibits the largest Li-ion diffusion coefficient ever measured in a solid. We use extensive characterisation (neutron, X-ray diffraction, impedance and NMR) as well as theoretical studies to study the lithium diffusion in LTPS. We show for instance with recent X-ray data that the Li mobility is so high that low temperature is needed to freeze and observe the lithium ions positions. We rationalise the exceptional performances of this new superionic conductor through the concept of frustrated energy landscape. The absence of regular and undistorted lithium site to occupy leads to low energy barrier for diffusion as well as an exceptional pre-factor. We discuss how this frustration could be present in previously known ionic conductors and be used to search and design new structural families of superionic conductors.
(Invited) Templated Electrodeposition By Molecular Assemblies: Exploring Limits
Authors: Yao Zhen , Buehl Michael , Buck Manfred 
Published: May 2020

Organic molecules play a vital role in deposition processes, both as randomly adsorbed entities to control kinetics and as organized layers in area selective deposition. Applications of the latter include deposition from the gas phase such as atomic layer deposition as well as from solution in processes ranging from electrochemical and electroless deposition of patterned metal films to the growth of layers of metal-organic frameworks. While self-assembled monolayers (SAMs) offer a convenient way to templated deposition down to the scale of tens of nanometers, the move towards the bottom end of the nanoscale poses increasingly stringent requirements on their structure and properties. This encompasses both the precision at which SAM patterns can be defined and the extent to which these layers can direct nucleation and control growth.
As far as electrodeposition is concerned, SAMs have been employed to generate metal patterns by harnessing their versatility and modifying a combination of interfacial properties such as adhesion and charge transfer. Typically, chemically passive molecules are used and the process is based on defects present in a SAM. Thus limiting resolution due to the statistical distribution of defects as regards their size and location, a complementary strategy where the deposition process can be actively controlled by a molecular property seems more promising to advance templated electrodeposition to the ultrasmall length scale. A scheme which affords such an active control is based on functionalized SAMs. As illustrated in the cartoon, metal ions are coordinated at the outer interface of the SAM (step 1) and reduced in a subsequent electrochemical step (2). Yielding deposits on top of the SAM, these can act as seeds for the deposition from the bulk electrolyte (3), thereby enabling the generation of ultrathin layers and the combination of different metals. Due to weak adhesion between the deposit and the SAM, structures can be lifted off and transferred to other substrates, thus offering a replicate generation of patterns.
The presentation addresses issues which are key to achieving ultrahigh resolution. Strategies aimed at overcoming current limitations as regards variability in dimensions are discussed, arguably one of the most pressing problems in the move towards ever smaller features. This involves topics ranging from the factors controlling coordination chemistry of SAMs to their design beyond single component systems.

Figure 1
Directly Generated Hydrogen to Feed a 2.4 Kw PEM Fuel Cell Stack By Hydrolysis of Nanoporous Aluminum with Pure Water
Authors: van der Pluijm Martijn W.G. , Chen Randy , Lee Asaph , Mui Jonathan , Corsi John S , De Hosson Jeff T.M. , Detsi Eric 
Published: May 2020

Jules Verne stated more than 145 years ago that water will be the coal of the future [1]. Indeed, hydrogen, a highly abundant substance on Earth in the form of water, is a promising energy carrier for producing zero-emission electricity upon reaction with oxygen using fuel cell technology. There are still many scientiﬁc and engineering challenges that need to be addressed before Jules Verne’s dream can become true, however. Two of these challenges include hydrogen production from water and hydrogen storage. In this talk, I will present our work on direct hydrogen generation by hydrolysis of nanoporous aluminum in pure water to feed a 2.4 kW PEM fuel cell stack, which in turn can be used to power a low speed electric vehicle. The possibility to make nanoporous aluminum from secondary aluminum and the advent of carbon-free primary aluminum from Elysis [2,3] could make hydrogen production by hydrolysis of aluminum with pure water a promising alternative to hydrogen production by electrolysis of water.

References:

[1] Ryabchuk, V. K., Kuznetsov, V. N., Emeline, A. V., Artem’ev, Y. M., Kataeva, G. V., Horikoshi, S., & Serpone, N. (2016). Waterwill be the coal of the future-the untamed dream of Jules Verne for a solar fuel. Molecules, 21(12), 1–20. https://doi.org/10.3390/molecules21121638
[2] Corsi, J. S., Fu, J., Wang, Z., Lee, T., Ng, A. K., & Detsi, E. (2019). Hierarchical Bulk Nanoporous Aluminum for On-Site Generation of Hydrogen by Hydrolysis in Pure Water and Combustion of Solid Fuels. ACS Sustainable Chemistry and Engineering, 7, 11194–11204. https://doi.org/10.1021/acssuschemeng.9b00481
[3] ELYSIS. Retrieved from https://www.alcoa.com/global/en/what-we-do/elysis/.
Quantifying Nucleation Rates in Phase-Transforming Metal-Ion Intercalation Materials Based on Cyclic Voltammetry and Chronoamperometry Data
Authors: Nikitina Victoria A 
Published: May 2020

Phase-transforming cathode materials with a wide miscibility gap have been extensively studied for both Li-ion (LiFePO4, Li4Ti5O12) and Na-ion (Na3V2(PO4)3) batteries. In particular, LiFePO4 material has become a model system for the investigation of intercalation induced phase transformation mechanisms.1 Most of the state-of-the-art research on the phase-separating intercalation materials focuses on the elucidation of phase transformation mechanisms as well as on the theoretical assessment of the nucleation barrier heights based on the evidence from structural investigation and microscopic single particle-level experiments.2

In this work, we show that the new phase nucleation appears to be a characteristic rate-determining step for a wide range of intercalation materials (LiFePO4, V2O5, cation-rich Prussian blue analogues, Na3V2(PO4)3). We demonstrate that the nucleation rates (probabilities of critical nucleus formation) can be straightforwardly determined from the electrochemical experimental data. A simple experimental approach is proposed based on the classical nucleation theory toward interpreting electrochemical cyclic voltammetry and chronoamperometry data for phase-transforming electrodes.3 The new methodology provides for a facile assessment of the influence of various experimental factors (particle size, defect concentration, solvent nature, and surface coating) on the nucleation-controlled phase-transformation rates in intercalation materials.4 Experimental data analysis illustrates the validity of the applied approaches, which allows developing diagnostic criteria for distinguishing slow nucleation rate control from other possible rate-determining steps as well as obtaining quantitative estimates of the nucleation rate constants.

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1. Malik, R.; Abdellahi, A.; Ceder, G. J. Electrochem. Soc. 2013, 160, A3179.
2. Bai, P.; Bazant, M. Z. Nat. Commun. 2014,
5, 3585.
3. Vassiliev, S.Yu.; Levin, E.E; Presnov, D.E; Nikitina, V.A. J. Electrochem. Soc. 2019, 166, A829.
4. Iarchuk, A.R.; Nikitina, V.A.; Karpushkin, E.A.; Sergeyev, V.G.; Antipov, E.V.; Stevenson, K.J.; Abakumov, A.M. ChemElectroChem 2019, 6, 5090.

Figure 1
Palladium Electrodeposition from Deep Eutectic Solvents
Authors: Soma Fousséni , Baustert Christophe , Rayée Quentin , Bougouma Moussa , Doneux Thomas , Buess-Herman Claudine 
Published: May 2020

Palladium is a platinum group metal that has been reported to be useful as electrocatalyst for several important reactions such as formic acid oxidation, alcohol oxidation and oxygen reduction. In this context the electrodeposition of Pd is of particular interest.
Palladium electrodeposition in aqueous media requires potentials close to the decomposition of water, leading to low faradaic yields and embrittlement of electrodeposited palladium. The use of unconventional solvents such as deep eutectic solvents (DESs) is expending as a promising alternative for the electrochemical deposition of metals. These are obtained by mixing a quaternary ammonium salt and a hydrogen-bond donor, leading to a melting point much lower than the pure components. These eutectics are easy to prepare, inexpensive and offer a high electrical conductivity. Owing to their thermal stability and wide electrochemical window, these media become more widespread in the field of metal electrodeposition, though fundamental studies are relatively scarce.
The present work focuses on the electrodeposition of palladium from deep eutectic solvents based on choline chloride.
The electrochemical behaviour of Pd(II) has been investigated at 60°C in choline chloride–urea (ChCl-U) and choline chloride–oxalic acid (ChCl-Ox). Cyclic voltammetry (CV) and potentiostatic measurements performed in the presence of Pd(II) at a glassy carbon electrode (GC) are compared with data obtained at a gold electrode.
Peaks in the CV curves are assigned to the Pd deposition and its dissolution but also to the formation of palladium hydride (PdHx). The Pd(II) electrochemistry is significantly different in the two DESs, owing to their differing proton donating properties and Pd speciation.
By selecting appropriate potentials, Pd electrodeposits were formed and analysed. The kinetics of Pd electrodeposition was followed by chronoamperometry. The i-t curves obtained at a glassy carbon electrode clearly revealed that the metal deposition is controlled by a nucleation and growth process. The current transients, discussed on the basis of existing models, indicate that the deposition occurs via 3D nucleation with diffusion controlled growth.
Initial Stage of Si Electrodeposition Process in Ionic Liquids
Authors: Homma Takayuki , Tsuyuki Yasuhiro , Kunimoto Masahiro , Fukunaka Yasuhiro , Pianetta Piero A. 
Published: May 2020

Si thin films are key material for electronic/energy devices such as photovoltaic cells and battery electrodes, as well as various MEMS devices. For their fabrication process, electrochemical approaches attract attention featuring high productivity and precise controllability to form micro/nano structures to wide surfaces. Since Si has very negative redox potential, non-aqueous electrolytes with molten salts, ionic liquids (ILs), or organic solvents are required. We have applied the ILs such as trimethylhexyl ammonium (TMHA+) bis-trifluorosulfonyl imide (TFSI-) and investigated their deposition process focusing upon the initial stage. The analysis using electrochemical quartz crystal microbalance (EQCM) [1] suggested that the reaction of the source of Si in the electrolyte, SiCl4, proceeded via Si (III) and Si(II) intermediate species. From the results of X-ray reflection (XRR) analysis and density functional theory calculation [2], it was indicated that the SiCl4 species adsorped onto the surface initially formed multimer, and this “precursor” was subsequently transformed into Si layers.
The authors would like to thank Dr. J. Komadina, Mr. M. Nishida, and Mr. T. Fujimura for their experimental help and valuable discussion. This study was financially supported in part by the Japan Science and Technology Agency (JST) CREST program.
[1] Y. Tsuyuki, A. Pham, J. Komadina, Y. Fukunaka, T. Homma, Electrochim. Acta, 183, 49 (2015).
[2] Y. Tsuyuki, T. Fujimura, M. Kunimoto, Y. Fukunaka, P. Pianetta, T. Homma, J. Electrochem. Soc., 164, D994 (2017).