bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal Analysis of the System NaCl–CaCl2–CaO
Authors: Savchuk Ruslan N. , Gritsai Larisa V. , Blyznyuk Antonina V , Skryptun Igor N 
Published: February 2020

The property of the systems MCl-CaCl 2 and MCl-CaCl2-CaO (where M is a alkali metal) allow its used in many processes of modern industry, in particular for the production of metals. However, in spite of this the information on the diagrams of the state of ternary systems of MCl-CaCl2-CaO and the behavior of refractory metal oxides in these melt is extremely limited.
This work shows the results of thermal analysis of partial cuts the ternary system NaCl-CaCl2-CaO.
The table 1 shows the compositions and the melting point (crystallization point) characteristic points of the system NaCl-CaCl2-CaO.
Table 1. The composition and melting point (crystallization point) of characteristic points.

System
T °C
Concentrate and I component in , %
The character of the point

Na Cl
CaO
CaCl 2

Na Cl - CaCl 2

500
0.490
-
0.510

Eutectic (
e

1

)

CaO - CaCl 2

750
-
0.065
0.935

Eutectic
(
e

2

)

835
-
0.185
0.715

Peritec
t
ic (
p

2

)

500
0.470
0.05
0.480

Eutectic (
E
)

The results of investigation partial cuts ternary system showing that in the concentration range 0–20 mol.% CaO ternary system NaCl-CaCl2-CaO is eutectic. The composition of eutectic (in mol.%) is NaCl(0.47)-CaCl2(0.48)-CaO(0.05) and its molten point is 480 °C. In the fused samples the phases of the initial components of the system are identified. Solid solutions and phases of the composition Ca(OCl)2 was not detected.
Electrochemical Synthesis of Tantalum Silicides from Chloride-Fluoride Melts
Authors: Devyatkin Sergei Vladimirovich 
Published: February 2020

Tantalum silicides: Ta3Si (Tm = 2613 К) , Ta2Si (Tm = 2783 К), Ta5Si3 (Tm = 2833 К) and TaSi2 (Tm = 2313 К) belong to refractory compounds. In the series of refractory compounds, silicides are distinguished by a high chemical stability at high temperatures; therefore, they widely used as protective materials in the chemical industry. Thanks to semiconductor properties and thermal stability, tantalum silicides promise much as a substitute for silicon in microcircuits.
Based on thermodynamic calculation and voltammetric studies, it has been concluded that the synthesis of tantalum silicides is the most electropositive process in the NaCl-KCl-K2SiF6-K2TaF7 melts.
Only the compound Ta2Si as coatings or powders has been obtained by electrosynthesis of the NaCl-KCl-K2SiF6-K2TaF7 melt at 973 K.
Photo-Healable Materials Based on Block Copolymers and Ionic Liquids
Authors: Watanabe Masayoshi 
Published: February 2020

Ion gels are composed of ionic liquids (ILs) immobilized within a three-dimensional molecular network. Such gels preserve the attractive physicochemical properties of ILs, such as nonvolatility, thermal stability, electrochemical stability, and high ionic conductivity, while maintaining a soft solid consistency. Ion gels are a novel platform for many applications such as electrolyte membranes, actuators, gas-separation membranes, flexible electrochemiluminescent gels, and organic thin-film transistors.
We present here the reversible micellization and sol-gel transition of block copolymer solutions in an IL triggered by a photostimulus. The ABA triblock copolymer employed consists of a random copolymer A block, including thermosensitive N-isopropylacrylamide (NIPAm) units and a methacrylate incorporating an azobenzene chromophore into the side chain (AzoMA); the B block is composed of an IL-soluble poly(ethylene oxide) (PEO) (P(AzoMA-r-NIPAm)-b-PEO-b-P(AzoMA-r-NIPAm)). We observed a reversible unimer-to-micelle transition of a dilute ABA triblock copolymer (1 wt%) in an IL, 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim]PF6) induced by photostimuli at an intermediate, “bistable” temperature. We demonstrate a reversible sol-gel transition cycle of the ion gel at the bistable temperature, with reversible association and fragmentation of the polymer network structure consisting of the self-assembled ABA triblock copolymer (20 wt%) in [C4mim]PF6. Such sol-gel transition has been utilized to design photo-healable materials. Damaged part of materials is UV-irradiated to convert gel to sol, followed by irradiated by visible light in order to convert again sol to gel. By this procedure, the damaged part was demonstrated to be healed to the original state (Figure 1).
Furthermore, we propose moving the azobenzene groups from the polymer chains to the IL structure as a molecular-level photoswitchable IL. Photoisomerization of an azobenzene IL at the molecular level can evoke a macroscopic response (light-controlled mechanical sol-gel transitions) for ABA triblock copolymer solutions. Therefore, an azobenzene IL as a molecular switch can tune the self-assembly of a thermoresponsive polymer, leading to macroscopic light-controlled sol-gel transitions. Surprisingly, a sight change in chemical structures of thermosensitive A segments induces opposite photo responsiveness, unimer/micelle transition and sol/gel transition, against UV/Vis-irradiation.

Figure 1. Photographs showing photo-healing of a star shaped ABA ion gel (20 wt%) cut at the center: (Left) damage before applying light stimuli, (Right) completely repaired damaged part after 64 h UV-light exposure, followed by 30 min visible-light exposure. The cracked part is highlighted by white dotted square.

Figure 1
(Invited) Ion Clusters and Li Transport in [Pyr12O1][FTFSI] Ionic Liquid-Based Electrolytes
Authors: Giffin Guinevere A , Moretti Arianna , Jeong Sangsik , Pilar Kartik , Brinkkoetter Marc , Greenbaum Steven , Schonhoff Monika , Passerini Stefano 
Published: February 2020

The use of highly concentrated, binary ionic liquid/Li salt electrolytes with the novel asymmetric anion FTFSI results in improved rate capability and capacity retention at 20°C, as compared to Li+-diluted systems, in Li-metal and Li-ion cells [1]. This work explores the connection between the bulk electrolyte properties and the molecular organization to give insight into the concentration dependence of the Li+ transport mechanisms. Below 30 mol%, the Li+-containing species are primarily smaller complexes (one Li+ cation) and the Li+ ion transport is mostly derived from the vehicular transport. Above 30%, where the viscosity is substantially higher and the conductivity lower, the Li+-containing species are a mix of small and large complexes (one and more than one Li+ cation, respectively). The overall conduction mechanism likely changes to favor structural diffusion via the exchange of anions in the first Li+ solvation shell [2]. The good rate performance is likely directly influenced by the presence of the larger Li+ complexes, which promote Li+-ion transport (as opposed to Li+-complex transport) and increase the Li+ availability at the electrode. In fact, electrophoretic NMR shows that Li is predominantly migrating in negatively charged Li-anion clusters towards the anode. However, this vehicular transport mechanism has decreasing relevance at elevated Li+ concentrations.
References
G. A. Giffin, A. Moretti, S. Jeong and S. Passerini, J. Power Sources, 2017, 342, 335-341.
G. A. Giffin, A. Moretti, S. Jeong, K. Pilar, M. Brinkkötter, S. G. Greenbaum, M. Schönhoff and S. Passerini, ChemSusChem, 2018, doi:10.1002/cssc.201702288.
M. Brinkkötter, G. A. Giffin, A. Moretti, S. Jeong, S. Passerini and M Schönhoff, Chem Comm, 2018, submitted for publication
Theoretical Investigation of the Catalytic Activity of Goethite (α-FeOOH) for the Electrochemical Water Oxidation
Authors: Lee Tae Hyung , Jang Ho Won 
Published: February 2020

Recently, to replace the expansive noble metals in electrocatalyst, transition metals with low cost and comparable performances are chosen as substitutes. Among transition metals, iron, which is one of the most abundant metal in the earth crust, is relatively out of the attention as an electrocatalyst. Due to its earth abundance and well-organized production system, iron has the one-tenth price of nickel, and even one-fiftieth price for cobalt. Considering that the ultimate goal of the water electrocatalysis system is an integrated system with a photovoltaic cell which demands the scale-up processing, the cost competitiveness can be maximized for the commercialization.
To enjoy the strong cost competitiveness of the iron, the poor catalytic property of the iron based electrocatalysts, particularly its low current density should be enhanced. According to several studies, it is known that certain phase, iron oxyhydroxide, can have much higher current density than existing iron-based electrocatalysts. Especially, iron oxihydroxide (FeOOH) belongs to thermodynamically stable form among iron oxides and presented to have enhanced catalytic property by experiments. Though, there are not enough theoretical investigations on its catalytic activity.
Herein, we investigate the water oxidation mechanism on the Iron oxyhydroxide(FeOOH) electrocatalysts using first-principles calculations based on Density Functional Theory. With calculations of relative surface stabilities and adsorbate coverages, the most stable low-index surfaces of FeOOH will be determined. Next, with the determined FeOOH surfaces, we will compare the theoretical overpotentials achieved by calculating each oxygen evolution reaction steps. For each step, the magnetic state will be checked for the explanation of oxygen evolution reaction process. Furthermore, impacts of the various dopants such as Mn, Ni, Co will be also investigated. With the calculation using hybrid functional, the electronic structure of the iron oxyhydroxide, with and without dopants, will be obtained and it will give the explanation of different OER catalytic activity shown by iron oxyhydroxide with different dopants.
For the strict verification of the calculation data, experiment results of the bare and doped FeOOH will be also presented. All the alpha FeOOH samples are synthesized with electrodeposition method and their electrocatalytic properties will be evaluated. With the comparison of calculation and experiment data, it is expected to figure out how the dopants affect bulk properties, reaction at the surface of the FeOOH and eventually influence the electrocatalytic properties.
Fast Flame Annealed Porous CuFe2O4 for Photoelectrochemical Hydrogen Production
Authors: PARK Sangwook , Baek Ji Hyun , Jung Hyun Suk , Zheng Xiaolin 
Published: February 2020

Photoelectrochemical (PEC) water splitting is one of the promising renewable energy techniques that can store solar energy into one of the clean and renewable energy resources, hydrogen (H2). However, facilitating the renewable PEC water splitting system on a global scale is still challenging. Especially, finding suitable p-type photocathodes is critical which have a narrow bandgap, a great solar to hydrogen (STH) efficiency and economical fabrication processes with earth abundant elements. Metal oxides have shown remarkable advantages that satisfy the important requirements to be an excellent photocathode among the suggested candidates.
Copper ferrite (CuFe2O4) is a promising but rarely studied p-type photocathode based on the relatively narrow bandgap (~1.7eV) which can utilize a great portion of solar light to realize the maximum STH efficiency of ~30% and photocurrent of ~25mA/cm2 theoretically. In addition, CuFe2O4 has positive flat band and photocurrent onset potentials (~1.0 VRHE) that are critical to achieve high operating photocurrent with n-type photoanode for an ideally unbiased entire solar water splitting system. Moreover, it consists of earth abundant elements. However, there are still limiting features for the use of CuFe2O4 photocathode since it has shown a relatively poor photocurrent and the synthesis process inevitably requires long time annealing at high temperature to produce less defective and better crystalline material for a high charge transport property.
Here, we employed the rapid and high temperature (>980°C) flame as an annealing process for CuFe2O4 photocathode synthesis, demonstrating the significantly enhanced photocurrent (-1.82 mA/cm2 at 0.4VRHE in Ar purged 1M NaOH) as a single material photocathode whose photoactivity is greater than that of most studied photocathodes. There are several unique advantages of the flame annealing compared with other conventional annealing methods for the synthesis. For example, the flame does have negligible ramping time to reach high temperature above 980°C due to its short ignition delay time that finally makes the high crystalline CuFe2O4 in only 16 minutes. Moreover, the flame is operated in the open atmospheric environment and the amount of oxygen can be easily controlled by adjusting the fuel to oxygen equivalence ratio as a combustion parameter. Oxygen rich environment was employed for CuFe2O4 annealing to provide fully oxidized condition for an amorphous Cu and Fe mixture prepared by sol-gel method. Finally, the porosity of CuFe2O4 was highly increased by flame annealing, and the physical structural change positively affects the enhancement of the light absorption property and the specific surface area increase.
Novel Photoelectrochemical Fuel Cell System Utilizing Titania Photocatalysts
Authors: De Carvalho Rafaela Cristina , Cassidy John , Betts Anthony 
Published: February 2020

In this work, one compartment Photoelectrochemical Cell (PEC) fabricated with inexpensive materials photodegraded selected organic compounds present in model waste waters, with the advantage of producing electrical current. Degradation of pollutants in waste waters by photoeletrocatalysis is well known. The photoelectrocatalytic degradation behaviour of the anti-inflammatory Sodium Diclofenac and others organic contaminants in aqueous solution was studied. TiO2 was utilized as the catalyst under different sources of UV and solar radiance. The catalyst was immobilized in a carbon cloth and in a variety of conductive supports as the photoanode and an air-cathode was utilized to allow an increase in oxygen concentration during the reduction process. By utilizing this photocatalytic process in a Photo Fuel Cell (PFC) device, the rate of organic pollutants destruction may be greatly enhanced, at the same time producing useful electrical energy.
A range of environmental conditions will be explored such as fuel/pollutant concentration level, electrolyte composition and pH variation, in order to determine the best performing catalyst/support/environment combination. A transition metal oxide-based air cathode will also be used (replacing expensive platinum) in conjunction with a modified PFC design, thus characteristics and mechanistic insights will be ascertained as a result.
Renewable Fuels: The European Union Research and Innovation Policies
Authors: Georgiadou Maria 
Published: February 2020

Horizon 2020 [1] and its successor Horizon Europe [2] provide the research and innovation framework to support the European Union policies for strengthening its scientific and technological basis in order to deliver on citizen's priorities and shared worldwide values, like fighting global challenges. Actions under the challenge "Secure, clean and efficient energy" of Horizon 2020 answer to the need for cost-effective and secure renewable fuel production to assist the decarbonisation of the energy and transport sectors and contribute to limiting the temperature increase to 1.5°C above pre-industrial levels. Being part of Mission Innovation [3] challenges "Converting sunlight into storable solar fuels" and "Sustainable Biofuels", the European Union leads research in renewable and breakthrough fuel technologies through dedicated actions in the Horizon 2020 Energy Work Programme [4]. Disruptive technologies for renewable fuels that outperform fossil fuels are also included. Dedicated topics on solar fuels and international collaboration opportunities worldwide will be presented. Furthermore, the inducement prize "Fuel from the Sun: Artificial Photosynthesis" which was launched in December 2017 [5] will be covered. Future support under Horizon-Europe will be presented.

References

[1] https://ec.europa.eu/programmes/horizon2020/
[2] http://ec.europa.eu/horizon-europe
[3] http://mission-innovation.net/
[4] http://ec.europa.eu/programmes/horizon2020/en/h2020-section/secure-clean-and-efficient-energy
[5] https://ec.europa.eu/research/eic/index.cfm?pg=prizes#sunfuel
Solution-Processable Electroactive Polymers As Active Materials for Macroscale Energy-Storage Devices with High-Rate Capability
Authors: Long Jeffrey W. , Sassin Megan B. , Ӧsterholm Anna , Reynolds John R 
Published: February 2020

Electroactive polymers have long been investigated as prospective charge-storage materials for electrochemical capacitors and rechargeable batteries. Conventional synthetic routes to such polymers have relied on electrodeposition, typically as thin films at planar substrates, or solution-phase methods that yield precipitates, which can be difficult to incorporate into composite-electrode structures. Recently, the Reynolds group at Georgia Tech has developed a family of solution-processable electroactive polymers, whose solubility characteristics are tuned via side-chain derivatization of ProDOT and EDOT structures [1,2]. We exploit the tailorable solubility of these polymers to facilitate their incorporation into macroscopically thick carbon nanotube/nanofiber papers. By distributing the polymer as a thin coating on a 3D carbon-based current collector, the inherent high-rate character of the polymer is maintained while the capacitance/capacity per geometric footprint is amplified by factors of ten or greater compared to analogous thin films. The chemical nature of these polymers can also be varied to achieve charge-storage functionality in either aqueous or nonaqueous electrolytes, which expands the range of electrochemical device configurations that will benefit from these advanced electrode materials. To demonstrate the technological promise of polymer–carbon electrode architectures, we perform electrochemical tests in three-electrode cells and two-terminal devices, assessing such critical characteristics as rate-dependent capacitance/capacity, self-discharge, and cycle life.
1. Ponder Jr., J. F.; Österholm, A. M.; Reynolds, J. R. “Designing a Soluble PEDOT Analogue without Surfactants or Dispersants,” Macromolecules
49, 2106 (2016).
2. Österholm, A. M.; Ponder Jr., J. F.; Kerszulis, J. A.; Reynolds, J. R., “Solution Processed PEDOT Analogues in Electrochemical Supercapacitors,” ACS Appl. Mater. Interfaces
8, 13492 (2016).
(Invited) Materials Development for Organic Redox Flow Batteries
Authors: Wei Xiaoliang 
Published: February 2020

Because of the excellent scalability and design flexibility, redox flow batteries are especially advantageous for grid-scale energy storage. Traditional inorganic-based flow batteries are generally limited by the low energy density and high chemical costs, which greatly restricted their widespread market penetration. In this regard, organic redox-active materials have been reported as possible materials alternatives to exhibit encouraging properties and performance.1
,2 The development of organic materials have suggested a promising avenue for enabling next-generation redox flow batteries, although further improvements are still urgently needed to demonstrate their commercialization potential.
In this presentation, we will introduce our recent progress in developing aqueous organic flow battery materials and systems. Among a variety of organic candidates being investigated, a few have demonstrated high effective electron solubilities >3 M, favorable redox potentials to enable high cell voltages, and highly scalable synthesis leading to cost-effectiveness. More importantly, we have achieved basic structure-property understandings of the key factors that govern the solubility and chemical stability of organic redox-active materials. These have provided guidance for rational materials design and development strategies to harvest significantly improved energy density and cyclability of flow batteries.

References

X. Wei, W. Pan, W. Duan, A. Hollas, Z. Yang, B. Li, Z. Nie, J. Liu,D. Reed, W. Wang, V. Sprenkle, Materials and Systems for Organic Redox Flow Batteries: Status and Challenges. ACS Energy Lett.
2017,
2, 2187.

A. Hollas, X. Wei, M. Vijayakumar, Z. Nie, B. Li, D. Reed, J. Liu, V. Sprenkle, W. Wang, A Nature-Inspired, Energy-Dense Phenazine-based Anolyte for Aqueous Organic Redox Flow Batteries. Nat. Energy, accepted.

Figure 1. Cycling efficiency and capacity for an aqueous organic flow battery.

Figure 1
Systematic Development of Positive Active Materials for Nonaqueous Redox Flow Batteries Using Phenothiazine As a Learning Platform
Authors: Kowalski Jeffrey A , Attanayake N. Harsha , Odom Susan A. , Brushett Fikile R. 
Published: February 2020

There is an increasing demand for stationary energy storage systems to facilitate the integration of intermittent, renewable energy sources (e.g. wind, solar) and to improve the efficiency, reliability, and resiliency of the existing fossil fuel infrastructure. Redox flow batteries (RFBs) are electrochemical energy storage devices that are well suited for grid storage due to decoupled power and energy scaling, long operating lifetimes, and simplified manufacturing1. While state-of-the-art RFBs utilize transition metal salts to store energy, they are currently too expensive to meet the stringent targets set by the U.S. Department of Energy ($100/kWh)2, motivating research in novel organic charge storage materials which may enable a pathway to low cost through tunable molecular structure and inexpensive synthesis routes3.
This work focuses on the use of phenothiazine and its derivatives as a robust learning platform to investigate the impact of substituent group addition on the molecular properties with an overarching goal of developing structure-function relations that enable deterministic multi-property optimization. Specifically, we seek to improve the equivalent charge concentration of redox electrolytes containing phenothiazines, by enhancing the solubility and intrinsic storage capacity through a combination of molecular engineering and electrochemical analysis. Building from N-ethylphenothiazine, we find judicious application of substituent groups can lead to significant performance enhancements, but care must be taken to avoid improving one property at the expense of others.
References

A. Z. Weber et al., J. Appl. Electrochem., 41, 1137–1164 (2011).

A. A. Akhil et al., Ed Albuq. NM Sandia Natl. Lab. (2013) http://www.emnrd.state.nm.us/ECMD/RenewableEnergy/documents/SNL-ElectricityStorageHandbook2013.pdf.

J. A. Kowalski, L. Su, J. D. Milshtein, and F. R. Brushett, Curr. Opin. Chem. Eng., 13, 45–52 (2016).