bluuebunny/crossref_metadata_2025_split huggingface dataset:
Free-Standing Two Dimensional MoS2 nanosheet/Acitvated Carbon Clothes Composite for High Performance of Supercapacitor
Authors: Sari Fitri Nur Indah , Ting Jyh-Ming 
Published: February 2020

Two dimensional (2D) MoS2 nanosheet has been successfully grown on Activated Carbon Clothes (ACC) by facile method, microwave-assisted hydrothermal at a shorter time. We have investigated the growth mechanism at different time reactions and their performance as electrode material of supercapacitor. Scanning electron microscopy (SEM) confirmed that time reaction controls the morphology and growth orientation of MoS2. On the other hand, it was found from the X-Ray Photoelectron Spectroscopy (XPS) that the additional phase which is MoO3 was formed during the reaction. This phase contributed to the performance by giving an additional pseudocapacitance. Furthermore, the intimate contact between MoS2 and ACC favor for fast electron transport during the charge and discharge. As a result, MoS2/ACC composite shows an excellent performance with specific capacitance of 230 F g-1 at a scan rate of 5 mV s-1 in 1M H2SO4 and high energy density of 79.9 W h kg-1 at high power density of 1044 W kg-1. Noteworthy, by growing MoS2 on ACC, the specific capacitance of MoS2 is 913.7 F g-1 which is the highest that ever been reported. Furthermore, this free-standing material is a promising material for a flexible supercapacitor.
Keywords: MoS2, microwave-assisted hydrothermal, supercapacitor, energy density.
Production of Ethanol in Electrochemical Cell Using Saccharomyces Cereviseae and Wickerhamomyces Anomalous As Counter Microbes
Authors: Joshi Jarina , Shrestha Rejeena , Manandhar Krishna , Sreerama Lakshmaiya , Bhattarai Tribikram 
Published: February 2020

Ethanol production by the yeast strains Saccharomyces cerevisiae and Wickerhamomyces anomalous was done by simultaneously cultivating the yeasts in the anode and the cathode of an electrochemical cell alternatively on either side of the electrolytic compartments. When Saccharomyces cerevisiae was cultivated on a platinum plate anode and Wickerhamomyces anomalus was cultivated in graphite rod cathode and an external electric potential of 4V was applied to induce the electrochemical redox reaction in the anode and cathode compartment of an electrochemical cell using glucose as a substrate, 27.61±0.35 mg/ml ethanol was produced. However counter combination produced only 24.78±0.45 mg/ml ethanol. Electrochemical oxidation potential inhibited Wickerhamomyces anomalus but showed a reduced effect on Saccharomyces cerevisiae. Graphite rod when modified by the immobilization of neutral red as a mediator of electron transfer showed improvement in ethanol production. The Wickerhamomyces anomalus when cultured with modified graphite rod and Saccharomyces cerevisiae when cultured in the anode 11.67% more than the neutral red non-immobilized combination of Saccharomyces cerevisiae and Wickerhamomyces anomalusand 64.28% more than that of the control maintained without the supply of external voltage.
Key words: Saccharomyces cerevisiae, Wickerhamomyces anomalus, Electrochemical cell, Neutral red, Platinum, Graphite rod

References

D.H Park, “Microbial Utilization of Electrically Reduced Neutral Red as The Sole Electron Donor for Growth and Metabolite Production.1999, Applied and environmental Microbiology, July1999, p.2912.

Jeon, Bo Young and Doo Hyun Park (2009), “Improvement of Ethanol Production by Electrochemical Redox Combination of Zymomonas mobilis and Saccharomyces cerevisiae,” 2010, J. Microbiol. Biotechnol., 20(1), 94.

Korneel Rabaey et al, “A microbial fuel cell capable of converting glucose to electricity at high rate and efficiency,”, 2003, Biotechnology letters25: 1531.

Abril D and Abril A., Ethanol from lignicellulosic biomass. 2009, Cien. Inv. Agr., Vol. 36(2), 177.

Delaney, G. M.; Bennetto, H. P.; Mason, J. R.; Roller, S. D.; Stirling, J. L.; Thurston, C. F. "Electron-transfer coupling in microbial fuel cells. Performance of fuel cells containing selected microorganism-mediator-substrate combinations". 2008, Journal of Chemical Technology and Biotechnology. Biotechnology 34: 13.

Jarina Joshi, Rejeena Shrestha, Rojlina Manandhar, Dinita Sharma, Krishna Manandhar, Lakshmaiah. Sreerama, Doo Hyun Park , Tribikram Bhattarai (2014). Optimization of External Potential for Ethanol Production by yeasts in electrochemical Cell. Rentech Symposium Compendium, Volume 4:44.
Thermodynamic Properties Determination in LiF-CaF2 using Electrochemistry in High Temperature Fused Salts: Application to CeF3
Authors: Gibilaro Mathieu , Massot Laurent , Chamelot Pierre 
Published: February 2020

Pyrochemical route is a promising option for spent nuclear fuel recycling. The major step of spent fuel reprocessing is the actinides-lanthanides separation performed by electrochemical processes. In this partitioning strategy, the most radiotoxic elements (actinides) are separated from the lowest ones (lanthanides) to decrease the volume of high activity nuclear waste disposal. The knowledge of thermodynamic properties (such as activities, standard potentials…) of actinides and lanthanides in solution is then crucial to predict their electrochemical behaviour in a complex multi-element system.
Thermodynamic calculations have been done on cerium fluoride in the LiF-CaF2 eutectics from 1113 to 1233K with FactSage and HSC 6.1 database. From electrochemical measurements (linear sweep voltammetry, equilibrium potential measurements…), the main thermodynamic properties needed for the electrochemical separation evaluation were determined: standard potentials and activity coefficients in different reference states (liquid or solid reference state, and infinite dilution reference state) and for different composition scales (molarity, molality, or molar fraction), and also standard enthalpy and standard entropy of formation in the 1113-1233K temperature range.
Finally, constants which interconnected the infinite dilution reference state and the solid and liquid reference states were evaluated.
Platinum Electrodeposition Methods to Enable Incorporation of Low Density Foam-Lined Hohlraums
Authors: Horwood Corie , Stadermann Michael , Bunn Thomas 
Published: February 2020

A low density foam liner, in place of a tamping gas, inside a hohlraum will reduce laser plasma interactions and possibly result in more uniform X-ray illumination on the capsule. Hohlraums made of gold are incompatible with a new chemical process to produce very low density, templated foams that possess excellent mechanical properties. Therefore, platinum is of interest for high-Z hohlraums because it is inert to the chemical etchants used to produce the low density foams. Platinum can be electrodeposited using commercially available aqueous electrolytes; however, published work on platinum electrodeposition has focused on thin films with high surface area. We will discuss electrochemical process developments that enabled non-porous, 3 - 20 μm thick Pt coatings on gold hohlraums, electroformed Pt hohlraums of thicknesses greater than 50 μm and a foam-lined hohlraum, where Pt was electrodeposited directly onto the foam starting material.
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Energy Saving Chlorine Electrolysis with Gas Diffusion Electrodes
Authors: Trieu Vinh , Bulan Andreas , Eiden Stefanie , Kintrup Juergen , Rittermeier André , Weber Rainer 
Published: February 2020

Chlorine is needed for some two-thirds of all chemical products, including plastics. And that comes at a cost. The production of this important basic chemical is one of the most energy-intensive processes in the chemical industry. In Germany the annual production of around 4.5 million tons of chlorine accounts to about 3% of the overall German electricity consumption. Thus, process innovation in chlorine manufacturing provides an important lever for tremendous savings of energy and their related carbon dioxide emissions.
The existing state-of-the-art chlorine processes of brine or hydrochloric acid electrolysis are already highly developed. A significant improvement is only possible by a major technology change. For conventional chlor-alkali electrolysis the reactions can be described as:
Anode: 2 NaCl = Cl2 + 2 e- + 2 Na+ (E0 = +1.36 V)
Cathode: 2 H2O + 2 Na+ + 2 e- = H2 + 2 NaOH (E0 = -0.83 V)
Replacing the cathode reaction of hydrogen evolution reaction by oxygen reduction reaction (ORR) would bring a drastic decrease of the overall electrolysis voltage due to thermodynamics.
Cathode: ½ O2 + H2O + 2 Na+ + 2 e- = 2 NaOH (E0 = +0.4 V)
Electrodes for efficient ORR are well known from fuel cell technology in form of gas diffusion electrodes. However, the implementation of gas diffusion electrodes in a chlorine evolving electrolysis is a challenge when it comes to industrial scale.
By interdisciplinary cooperation of industry partners and research institutes, significantly supported by public funding, the development of suited gas diffusion electrodes for chlorine electrolysis - also known as oxygen depolarized cathodes (ODC) - was successfully realized. The process has been operating on an industrial scale at Covestro’s plant in Krefeld-Uerdingen in Germany since 2011 and has been commercialized worldwide since 2013. As a result, up to 30 percent less electricity than for the conventional process is required.
The talk will highlight the technical requirements and the corresponding developments as well as the ecological and economic aspects of the use of gas diffusion electrodes for chlorine production.
Furthermore, the developed gas diffusion electrodes are the platform for future applications in the field of power generation, energy storage, water purification/disinfection and electrosynthesis.

Figure 1
Numerical Analysis of the Effect of Diaphragm Length, Position and Porosity on the Electric Field and Mass Transport inside a Lithium Electrolysis Cell
Authors: Oliaii Elaheh , Desilets Martin , Lantagne Gaétan 
Published: February 2020

Lithium is commercially produced by the electrolysis of lithium chloride. This process is expensive due to the high energy consumption of the electrolysis process. A noticeable part of the energy lost in this electrochemical cell is caused by back reactions, essentially between chlorine bubbles produced at the anode and liquid lithium produced at the cathode. The diaphragm has two opposite effects on the cell energy consumption: it increases the current efficiency through its preventive effect on back reactions; however, it increases the energy consumption of the cell by introducing extra ohmic overpotential. Furthermore, in a lithium electrolysis cell, the diaphragm characteristics significantly influence the mass transfer, electric and velocity fields.
A 2D axisymmetric electrochemical model of a lithium production cell is solved using a finite element method and used to minimize the cell energy consumption by optimizing the diaphragm characteristics and its position in the cell. The model is considering the coupled effect of momentum, electric, kinetic and mass transfer phenomena. The diaphragm separates the cell in two regions: 1- a turbulent region, between the anode and the diaphragm, and 2- a laminar region between the diaphragm and the cathode. The k-ε model is used to solve the turbulent flow resulting from bubbles generation at the anode. The bubbles cause an ohmic overpotential and hyperpolarization, considered through the resistive layer and bubble coverage at the surface of the anode. Furthermore, the effects of the diaphragm length, position and porosity on the electric field are simulated. In fact, the diaphragm position and length influence the current distribution at the surface of electrodes and the velocity distribution in the cell all of which influence ohmic and kinetic overpotentials.
The experimental cell, simulated as a base case on which the model has been validated, contains a dense alumina diaphragm. The results show that up to 40% energy is saved when running a lithium electrolysis cell with a smaller porous diaphragm located as far as possible from the anode. Moreover, the diaphragm deteriorates the current density distribution along the electrodes with a detrimental effect to the integrity of the electrodes. The maximum current density, found at the bottom corner of anode, is higher when the diaphragm is longer and when it is closer to the anode.
Finally, but not least, the results of this research are not only useful for improving the design of lithium production cells. They also could be extended and applied to the study of other molten salts electrochemical cells equipped with diaphragm.
Quantifying Potential Contributions in the Hybrid Sulfur Electrolyzer at Elevated Temperatures
Authors: Garrick Taylor R , Wilkins Cody H , Pingitore Andrew T , Gulledge Alexander , Benicewicz Brian , Weidner John W. 
Published: February 2020

The hybrid sulfur thermochemical cycle has seen much attention recently due to its potential to enable the production of clean hydrogen on a large scale with a higher energy efficiency than water electrolysis. The two step hybrid sulfur (HyS) process involves the high temperature decomposition of sulfuric acid to produce sulfur dioxide, oxygen, and water, as well as a low temperature electrochemical oxidation of sulfur dioxide in the presence of water to produce sulfuric acid and gaseous hydrogen. Due to the internal recycling of sulfur compounds in the HyS process, the overall balance is the decomposition of water to form gaseous hydrogen and oxygen. This process is interesting because the high temperature decomposition step could be coupled to next generation solar power plants or high temperature nuclear reactors in order to produce hydrogen for other applications.
Using a proton exchange membrane such as Nafion in the HyS electrolyzer has been thoroughly examined via the prediction of mass transport through the membrane as a function of operating potential and other design variables. However, Nafion presents several drawbacks, such as the inability to operate at elevated temperatures and the decreased performance seen when exposed to high acid concentrations. Previously, we showed that acid doped polybenzimidazole (PBI) membranes are an alternative to Nafion because they do not rely on water for proton conductivity, and therefore offer the possibility of operating at higher acid concentrations in order to minimize energy requirements necessary for water separation, as well as operation at higher temperatures in order to minimize voltage losses. Through the successful operation of the HyS electrolyzer using sulfuric acid doped PBI membranes, we have determined that despite the relative thickness of s-PBI, the area-specific resistance of s-PBI compares favorably with Nafion and is not adversely affected by the sulfuric acid concentration in the electrolyzer. Through further characterization of the membrane and the electrolyzer, we have been able to refine a model for high temperature and high pressure operation of the electrolyzer allowing for further analysis of the system in order to determine operating conditions that allow for economically viable operation of the HyS electrolyzer.
The dependence of the individual potential contributions on temperature and pressure will be discussed, as well as trends seen in the membrane conductivity as a function of operating conditions and produced acid concentrations. A discussion of model results illustrating future membrane design considerations will also be presented.
Fast Scan Cyclic Voltammetry with Microdialysis for Quantitative Measurement of Dopamine
Authors: Shin Hojin , Blaha Charles D , Bennet Kevin E , Lee Kendall H , Jang Dong Pyo 
Published: February 2020

Microdialysis methods have been widely used for the quantitative measurement of neurotransmitter concentrations in vivo. Because neurotransmitter efflux happens rapidly, microdialysis has a limit to detect neurochemical changes in the brain in real time. Fast-scan cyclic voltammetry (FSCV) is one of the electroanalytical methods to monitor neurotransmitter efflux such as dopamine, serotonin, adenosine, and ascorbic acid in the brain. Because conventional FSCV analyzes voltammagram differences to detect chemical substances, measuring concentrations of neurotransmitters is desirable. In a previous study we introduced a new method using multi-waveform cyclic voltammetry to reduce voltammogram differences and enhance sensitivity and selectivity.
In this study, we demonstrated FSCV with a carbon fiber microelectrode (CFM) adjacent to a microdialysis probe to measure concentration changes during microdialysis. Experiments were performed in agarose gel (0.1%) with a known concentration of dopamine inside, and perfusion of the dialysis probe with Tris-buffered saline (TBS, pH7.4, 5ul/min) decreased the baseline. After stabilization, a series of known concentrations of dopamine (200nM to 1uM) was perfused and concentration changes were monitored by FSCV until the decreased baseline was recovered. These results indicate that the amount of dopamine injected when decrease baseline is fully recovered reflects the concentration of dopamine inside the agarose gel. FSCV combined with microdialysis was also performed in the striatum of a rat, to monitor basal level of dopamine in the extracellular space of the brain.
Heparin Contained Multilayer Composite Coatings on NiTi Alloy By Electrochemical Methods for Reducing in-Stent Restenosis
Authors: Yen Shiow Kang , Liang Yu- Hsin , Zheng Po- Yin , Kao Chen- Yuan , Lai Yu-Liang , Lin Chien- Chung 
Published: February 2020

Although the initial success of bare metal stents (BMS) has significantly reduced the restenosis rate from 35% for Percutaneous transluminal coronary angioplasty (PTCA) to 25%, the biological mechanism such as smooth muscle cell proliferation and neointimal hyperplasia may still induce in-stent restenosis (ISR). Therefore, some drug eluting stents have been introduced to reduce ISR. In this study, heparin (Hep) combined with calcium phosphate (CaP) and gelatin (Gel) was co-deposited on NiTi alloy by electrochemical methods in order to fabricate the sustained heparin releasing system for promoting the hemo-compatibility of NiTi substrate. Polarization tests were carried out in several solutions to investigate deposition mechanisms. Heparin contained composite coatings are characterized by X-ray diffractometry (XRD), Field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FTIR), toluidine blue colorimetric assay, UV-visible spectrometer and kinetic clotting tests. The consequences indicate that heparin accompanied with CaP, and Gel through ionic bonds can be loaded on the NiTi alloy, respectively. The post porous HA coating can enhance the drug content from 147.06±68.66 of the single layer coating (CaP-Hep) to 191.58±11.87 of the bilayer coating (HA/CaP-Hep) and further to 324.87±4.94 μg/cm2 of the trilayer coating (HA/CaP-Hep/Gel-Hep) by adding the third layer which also results in the in vitro heparin release prolonging from 1 day burst to more than 35 days sustaining release. As the result of clotting tests, drug loaded composite coatings reveal good anticoagulant property which is proportional to the cumulative content of drug release in an hour, indicating no denaturalization of heparin found during the electrochemical process.
Keywords: Ni-Ti alloy; in-stent restenosis (ISR); heparin; calcium phosphate; gelatin
Multi-Scale Modeling of Cathode Performance in Solid Oxide Fuel Cells (SOFCs)
Authors: Geisler Helge , Joos Jochen , Weber André , Ivers-Tiffée Ellen 
Published: February 2020

A finite element method (FEM) based model was developed for performance simulation in SOFC, using a homogenized electrode microstructure at the cell level. The model was parametrized with electrode kinetics determined by electrochemical impedance spectroscopy (EIS) on planar anode supported cells and validated by current/voltage characteristics (C/V) over the technical relevant operating condition range of SOFC [1]. Model calculations on planar stack layer level have demonstrated that (i) cathode layer thickness and (ii) cathode layer porosity is key to avoid gas transport limitations and performance loss [2].
The model has been advanced by adopting mixed-ionic/electronic cathode (MIEC) kinetics, thus enabling the simulation of stack layer performance depending on the cathode’s chemical composition. Furthermore, it will be demonstrated how a functional gradient in pore and particle size distribution enhances stack performance compared to state-of-the-art cathodes. These simulations are not based on artificial, but on “real” microstructures, which were determined using a combined focused ion beam/scanning electron microscopy (FIB/SEM) and X-ray tomography reconstruction of a two-layer cathode.
[1] H. Geisler, A. Kromp, A. Weber and E. Ivers-Tiffée, JES 161 (6) F778-F788 (2014)
[2] H. Geisler, J. Joos, A. Weber and E. Ivers-Tiffée, ECS Transactions, 68 (1) 3043-3050 (2015)
The Investigation of Flow Channel Design on the Performance of PEM Fuel Cell
Authors: Wei Guanghua , Wang Chao , Jiang Chuanyu , Zhang Junliang 
Published: February 2020

The flow channel is very important to the performance of proton exchange membrane fuel cells (PEMFCs), it is believed that the PEM fuel cell performance is greatly affected by the flow patterns besides the operating temperature, gas inlet humidity, and so on [1,2,3]. The channel or rib width and channel cross-sectional area determine the pressure drop, thus directly influence on the water removal, and then affect the oxygen supply and oxygen reduction reaction. In this study, two flow pattern, four different channel designs are investigated mainly by three-dimensional simulation, effects of different design on cell performance are validated by the experiments. After analyzing the differences between the four kinds of flow channels, the situations of current density distribution, water distribution and oxygen distribution in the cell are studied and the performance are analyzed. We found out how the flow channel width and cross sectional area on the performance of PEM fuel cell: the narrower the width is, the better the cell’s performance is when current is low. The larger the cross sectional area is, the better the cell’s performance is when current is high.

Acknowledgements

This work was supported in part by National Natural Science Foundation of China (Grant No. 21533005) and Science Foundation of Ministry of Education of China ( Grant No. 413064).

References

[1] Bonghwan Lee, Kiwon Park and Hyung-Man Kim. Numerical Optimization of Flow Field Pattern by Mass Transfer and Electrochemical Reaction Characteristics in Proton Exchange Membrane Fuel Cells[J]. Int.J. Electrochem. Sci., 8 (2013) 219 – 234
[2] A. Arvay, J. French, J.-C. Wanga, X.-H. Peng, A.M. Kannan. Nature inspired flow field designs for proton exchange membrane fuel cell[J]International Journal of Hydrogen Energy 38(2013):3717-3726
[3] Sungho Lee, Heeseok Jeong, Byungki Ahn, Taewon Lim, Youngjin Son. Parametric study of the channel design at the bipolar plate in PEMFC performances[J].International journal of hydrogen energy 33 ( 2008 ) 5691–5696

Figure 1