bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding the Durability and Degradation of Gas Diffusion Electrodes for Carbon Dioxide Electrolysis in Alkaline Media
Authors: Cofell Emiliana R. , Nwabara Uzoma , Henckel Danielle A. , Kenis Paul 
Published: December 2020

Anthropogenic CO2 emissions present an immediate and unprecedented threat to our planet. Electroreduction of CO2 (ECO2RR) offers the dual benefits of reducing CO2 emissions from point sources and producing valuable chemicals such as CO, formic acid, and ethanol in a carbon-neutral manner.1,2 Over the past decade, a significant body of research has focused on improving the product selectivity and activity of CO2RR catalysts, but studies regarding long-term stability and durability of these electrocatalytic systems have been rare.3 To date, only a few studies have reported performance durations exceeding 100 hours, and even fewer have reported on possible mechanisms underlying decrease in performance and system failure.4 Techno-economic analyses suggest a lifetime of 3000 hours or greater is needed for economically feasible ECO2RR systems5. Progress in this area will be crucial for further development of ECO2RR technology.
This poster will report key findings from our comprehensive review of durability testing in ECO2RR systems, specifically common degradation mechanisms. We will focus primarily on gas diffusion electrodes (GDEs), used in high-performance alkaline flow and membrane electrode assembly systems. In our alkaline flow system, we have observed a number of degradation mechanisms consistently impacting our GDEs including leaching and carbonate formation. Characterization of used GDEs, including SEM, EDX, XRD, and Micro-CT, was employed to understand how operating at high current densities (–100 to –200 mA cm-2) in alkaline electrolytes impacts structure and chemical composition.
Secondly, this poster will outline ways in which we have attempted to improve durability in our GDEs. By applying insights from the literature to studies carried out in our flow system, we have evaluated changes in the electrolyte, electrode substrate, catalyst deposition method, and catalyst ink binder to optimize GDE design and augment durability. Lastly, we will report on accelerated durability and stress testing (ADT/AST) methods that we have developed, and our findings from implementation of these methods in our system. These accelerated procedures can be broadly applied to highly active (≥200 mA cm–2), lab-scale ECO2RR systems to determine long-term stability and degradation modes in shorter timeframes.

Acknowledgement

We gratefully acknowledge financial support from Shell’s New Energies Research & Technology - Dense Energy Carriers Program and I2CNER.

References:

Oerlemans, J. Science
308, 675-677 (2005).

Jhong, H. R., Ma, S. C. & Kenis, P. J. A. Curr Opin Chem Eng
2, 191-199 (2013).

Hori, Y. Mod Asp Electrochem, 89-189 (2008).

Cofell, E., Nwabara, O., Negro, E., Verma, S., Kenis, P. J. A., Chemsuschem
13, 855-875 (2020).

Verma, S., Kim, B., Jhong, H., Ma, S. C. & Kenis, P. J. A. Chemsuschem
9, 1972-1979 (2016).
Development of Short Time Impedance Measurement Method for PEM Electrolysis Cell
Authors: Murooka Takuki , Watanabe Hikari , Hoshi Yoshinao , Shitanda Isao , Itagaki Masayuki , Katayama Noboru , Sato Koki , Haneda Takahide 
Published: December 2020

Electrochemical impedance spectroscopy (EIS) is expected as a method to evaluate a polymer electrolyte membrane (PEM) water electrolysis cell. The internal state of electrolysis cell can be investigated by EIS without destruction. However, it may be difficult to measure stable impedance during electrolysis at high voltage since the large amount of oxygen is generated on the anode. Therefore, a short time impedance measurement is required. The purpose of this study is to develop short time impedance measurement method1,2) that can estimate the electrolyte membrane resistance R
M and the charge transfer resistance R
ct in a short time.
A Japan Automobile Research Institute (JARI) standard cell with an electrode area of 25 cm2 was used as the test cell. The impedance measurement was performed in a frequency range from 100 mHz to 1 kHz and started from high frequency toward low frequency in the logarithmic scan.
The Nyquist plot of impedance spectrum shows inductive behavior caused by wiring in the high frequency region and capacitive semicircle related to the anode in the middle frequency region. Under the condition of high current density, it was found that impedance spectrum was scattered in the low frequency range. The scattering originated from oxygen evolution at the anode when the measurement time is long. The measurement time was about 80 s to obtain an impedance spectrum, thus it is necessary to measure in a shorter time. Therefore, we obtained R
ct in a short time by the two-point frequency method proposed by Haruyama et al.1,2) The equation (1) is used to calculate R
ct.

R
ct = Re [Z] - R
M + Im [Z]2/( Re [Z] - R
M) (1)
In the equation (1), R
M is the electrolyte membrane resistance, which is the real component of the impedance at the high frequency. The real and imaginary parts of the impedance at the low frequency are represented by Re [Z] and Im [Z]. The measurement was performed by fixing the frequency at 1 kHz as a high frequency value and changing the low frequency value from 100 Hz to 10 mHz. R
ct obtained from the measurement results by the two-point frequency method was compared with R
ct obtained from the curve fitting of the impedance spectrum with the equivalent circuit. As a result, the relative error of the R
ct calculated from the measurements at two frequencies 1 kHz and 10 Hz was -2.15% from the fitted result, and the measurement time was 5.33 s. From these results, it was found that the two-point frequency method was able to reduce the measurement time significantly compared to the normal EIS and to estimate R
ct accurately.

References

1) S. Haruyama, T. Tsuru, ASTM STP 727, ASTM Philadelphia, p.167 (1981).
2) T. Tsuru, S. Haruyama, Boshoku Gijutsu, 33, p.579-582 (1984).
The Behavior of Microdroplets By the Acoustic Wave Interference
Authors: Lee Hai-Joong , Park Tae-Hoon , Lee Hyo-Soo 
Published: December 2020

The microdroplet in the air have been recently issued in the view of environmental pollution and infectious virus. The microdroplet with fine dust have been challenged to solve with conventional techniques such as filtering, electrostatic, etc. We investigated the novel technology for decreasing the fine particles in air induced by sound wave with the frequency ranging from 20Hz to 20kHz and the sound pressure level (SPL) from 0 to 100dB.
The test systems in our study were set up with constraint box, sound wave actuator, ultra-fine particle distributor, particle counter, decibel meter, etc. the variation of density of ultra-fine particles from distributor was characterized with operating time of sound wave, and compared with the density as no operating.
When the low frequency and the SPL under 50Hz and 100dB were applied in the constraint box containing ultra-fine particles, the rate of decrease of ultra-fine particles in density was nearly 5 times higher than that without operating. And it can be applied to increase the efficiency of the conventional particle collection technology such as the commercial filter.
It is concluded that the behavior of microdroplets was effectively analyzed by the acoustic wave interference, and also is expected to be applied to the various fields
Enhanced Photocatalytic Hydrogen Production with Treated Cus/Znos from S2-/so3
2- Solution
Authors: Hayashi Ryoya , Furukawa Mai , Tateishi Ikki , Katsumata Hideyuki , Kaneco Satoshi 
Published: December 2020

Recently, with the problems of energy environment and global warming, the use of hydrogen as energy in the future has been attracting attention. Also, waste water containing dyes causes environmental pollution and gives a harm for the health of living organisms [1].
Previously, we reported ZnO/ZnS composites for the photocatalytic hydrogen production. The photocatalyst ZnS/ZnO with CuS as a cocatalyst can simultaneously treat H2 production and dye decolorization. The hydrogen production was 2,110 µmol/g･h with CuS/ZnO0.5S0.5 (molar ratio ZnO/ZnS = 5/5). Furthermore, methyl orange solution of up to 80 ppm could be decolorized with about 90% efficiency.
In the present study, ZnOS was prepared via a solvothermal method [2]. Firstly, ZnS was prepared by hydrothermal synthesis.Typically, Zn(Ac)2･2H2O of 10 mmol and thiourea of 30 mmol were dissolved in 15 mL of pure water for stirring for 30 min at room temperature. Fourty mL of ethylenediamine were then added into the above aqueous solution. After the stirring for 30 min, the solution was added into 15 mL pure water, and was stirred for more 30 min. Next, autoclave treatment was perfprmed at 160 ℃ under autogenous pressure for 4 h. After cooling to room temperature, the products were washed with pure water and ethanol, and were dried at 60 ℃ in vacuum overnight. The ZnS photocatalyst was sintering at 600 ℃ for 2 hours convert to obtain ZnO. ZnO was dissolved in 50 mL of pure water. Next, Na2S was added to the aqueous solution during magnetic stirring. A nanocomposite of ZnO core and ZnS shell could be prepared. Sintering was performed in an air atmosphere using an electric furnace to obtain ZnOS.
The amount of hydrogen production using ZnOS with CuS as a cocatalyst was 2230 µmol / g･h.

References

[1] K. Chu, L. Ye, W. Wang, D. Wu, D. Chan, C. Zeng, H. Yip, J. C. Yu, P. Wong, Chemosphere
2017, 183, 219.
[2]P. Li, T. He, Appl. Catal. B : Environ.
2018, 238, 518
Direct Measurement of Electron Transfer Rates between Iron(II) Phthalocyanine and Gold with Different Interface Structures
Authors: Kondo Taisei , Motobayashi Kenta , Ikeda Katsuyoshi 
Published: December 2020

Electron transfer in a metal/molecule system has been extensively studied using various methods. In particular, the relation between the structure of metal/molecule junctions and the electron transfer property is of great interest in the research field of molecular devices. In this study, we measured electron transfer rates of iron(II) phthalocyanine/gold system with different junctions to study the contribution of the atomistic interfacial structures to the electron transfer characteristics.
An Au single-crystal disk with (111) or (100) orientation was modified with self-assembled monolayers of imidazole-terminated alkanethiols with the alkyl chain of ten carbon atoms (ImC10SH). Then, iron(II) phthalocyanine (FePc) complexes were attached on top of the monolayer through the axial ligation of the central Fe ions with the imidazole groups. The Au-S bonding structure was measured using Surface-enhanced Raman spectroscopy (SERS).1) The electron transfer rate between Au and FePc was measured by analyzing the cyclic voltammogram (CV) of redox behavior for FePc in 0.1 M perchloric acid aqueous solution.
SERS measurements showed that the Au-S bonding structures were different between Au(111) and Au(100). According to the peak position of nAu-S, the dominant Au-S structure was determined to be three-fold hollow geometry on Au(111) and two-fold bridge geometry on Au(100). Figure shows the scan rate dependence of CVs of FePc/ImC10SH/Au(100) and FePc/ImC10SH/Au(111). With increasing the scan rate, the peak separation between the oxidation and reduction peaks became larger in both cases. However, the magnitude of the separation was larger for Au(111) than for Au(100), suggesting that the electron transfer through the Au-S junction was slower at the hollow site on Au(111) than at the bridge site on Au(100). The electron transfer rate can be calculated from the relation between the peak separation and the scan rate. We will present detailed quantitative analysis of the electron transfer rate for different Au-S bond structures, alkyl chain lengths, etc.
1) M. Inagaki, K. Motobayashi, K, Ikeda, J. Phys. Chem. Lett., 8, 4236 (2017)
Figure. Scan rate dependence of CVs of FePc/ImC10SH/Au(100) and, FePc/ImC10SH/Au(111) in 0.1 M perchloric acid aqueous solution.

Figure 1
Electrochemical Sensor for Food Toxins with Molecularly Imprinted Polymer for Selective Determination of Heterocyclic Aromatic Amines
Authors: Ayerdurai Viknasvarri , Garcia-Cruz Alvaro , Cieplak Maciej , Sharma Piyush Sindhu , D'Souza Francis , Kutner Wlodzimierz 
Published: December 2020

Quinoxaline heterocyclic aromatic amines (HAAs), are formed during meat and fish cooking, frying or grilling at high temperatures. HAAs are classified as potent hazardous carcinogens, even though the HAAs are usually generated at very low concentration (~ng per g of a food sample). This is because the HAA food contaminants effectively damage DNA by intercalation or strand break. Hence, chronic exposure to HAAs, even in low doses, can cause cancers of lung, stomach, breast, etc. Currently, HPLC is used for determination of these toxins in food matrices. However, this technique is expensive, tedious, and time-consuming. Therefore, fast, simple, inexpensive, and reliable HAAs determination procedures, without need of separation of these toxins, in the protein food matrices are in demand. Molecularly imprinted polymers (MIPs) are excellent examples of bio-mimicking recognition materials. Therefore, they have found numerous applications in selective chemosensing. Within the present project, we synthesized a nucleobase-functionalized molecularly imprinted polymer (MIP) as the recognition unit of a chemosensor for selective detection and determination of 2-amino-3,7,8-trimethyl-3H-imidazo[4,5-f]quinoxaline (7,8-DiMeIQx) HAA. MIP-(7,8-DiMeIQx)-film coated electrodes were sensitive and selective with respect to 7,8-DiMeIQx. The linear dynamic concentration range of the devised chemosensor extended from 12 µM to 0.4 mM 7,8-DiMeIQx and the imprinting factor was high, IF = 14.
This work is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 711859. Scientific work was funded from the financial resources for science in the years 2017-2021 awarded by the Polish Ministry of Science and Higher Education for the implementation of an international co-financed project and National Science Centre Poland (grant No. NCN 2014/15/B/NZ7/01011 to W.K.)
(Invited) Hybrid Nanomanufacturing of Heterostructured Wearable Devices for Self-powered Smart Wearables
Authors: Wu Wenzhuo 
Published: December 2020

The seamless and adaptive interactions between functional devices and their environment (e.g., the human body) are critical for advancing emerging technologies, e.g., wearable devices, consumer electronics, and human-machine interface. The state-of-the-art technologies, however, require a complex integration of heterogeneous components to interface the environmental, mechanical stimulus, which is ubiquitous and abundant in the above applications. These limitations have severely hampered the advancement and broader utilization of related technologies. Moreover, all existing technologies require a power source, which complicates the system design and limits operation schemes.
In this talk, I will discuss our recent progress in developing self-powered human-integrated nanodevices through the hybrid nanomanufacturing of heterostructured nanodevices. This new class of wearable devices are conformable to human skins and can sustainably perform self-powered, non-invasive functions, e.g., physiological monitoring and gesture recognition, by harvesting the operation power from the human body. Such an operation scheme is fundamentally hinged on the polarization induced current term in Maxwell’s displacement current. This research is expected to have a positive impact and immediate relevance to many societally pervasive areas, e.g., biomedical monitoring, consumer electronics, and intelligent robotics.
Application of Nanocarbons Modified with Anthraquinone Polycondensation Polymer to Electrochemical Double Layer Capacitance
Authors: Nishiyama Katsuhiko , Yamaguchi Kaisei , Minamoto Hironori , Yoshimoto Soichiro , Takafuji Makoto 
Published: December 2020

Carbon-based fine particles have been widely used as fillers for enhancing the reinforcement for bulk materials. In addition, the excellent physical stability and unique chemical properties of these fine particles expand their potential utility in electroconductive materials, carriers for catalysis, packing materials such as pigment and colorant for inks, paints, and resins. Recently, it was reported that one-pot polymerization of 1.5-dihydoroxynaphtalene (DHN) and 1,3,5-1,3,5-trimethyl-1,3,5-triazinane(TA) in ethanol or other related solvents without any additives, and subsequent calcination at relatively enables us to control the diameter of the resultant particle in the range of submicron to a couple of microns. In this study we report that the nano carbons modified with an anthraquinone polycondensation polymer prepared by this one-pot polymerization method using an aromatic hydrocarbon with OH groups and TA function as an electrochemical double layer capacitors (EDLC).
Anthraquinone derivatives having two OH groups and 1,3,5-trimethyl-1,3,5-triazinane (TA) were purchased from Tokyo Chemical Industry Co., Ltd. and used as received. Carbon black powders (DENKA Black) and mineral oil were purchased from DENKA Co. Ltd. and Sigma, respectively. Cyclic voltammetry (CV) and potential step chronocoulometry were performed with a ALS model 621 electrochemical analyzer. A platinum plate and Ag/AgCl (KCl sat.) were used as a counter and reference electrode, respectively.
CV in 0.1 M HClO4 at a bare carbon black (CB) electrode shows very small charging current without redox waves. In contrast, at the CB modified with anthraquinone condensation polymer (AQP), redox waves of anthraquinone moieties associated with a large charging current. The capacitance calculated from CV depended on the kind and concentration of the supporting electrolyte used, the kind of carbon black, and modification conditions of the AQP. The capacitance of 1.34 F cm-2 was obtained at the AQP modified CB (DENKA Black HS-100) in 0.1 M HClO4. This modification method is very simple, versatile, and effective for modifying nanocarbons.
Nano-Si/C Composite Via Carbothermal Shock for Lithium Ion Battery Anode
Authors: Cho Changhyun , Kim Soyeun , Kim Moosung , Joh Chung-Hyung , Lim Chang-ha , Woo Changse , Yang Kap seung , Park Min-Sik 
Published: December 2020

Nowadays, Li-ion batteries are ubiquitous and dominate the portable storage market. However, their utilizations for high-energy applications are limited and they present huge social challenges for the future, especially for the applications to electric and hybrid electric vehicles (EVs and HEVs respectively). One strategy, praised by both academics and industry, the high capacity electrode materials, notably silicon, as it is considered an attractive graphite substitute in Li-ion battery anode. Silicon (Si) is recognized as a representative anode material for next-generation lithium-ion batteries due to properties, such as a high theoretical capacity, suitable working voltage, and high natural abundance. However, inherently, a large volume expansion (~ 400%) during lithiation/delithiation introduces poor electrical conductivity and unstable solid electrolyte interfaces (SEI) films, the Si-based anodes possess serious stability problems hindering practical applications. To overcome the issue, Si-nanoparticles(Si-NPs) has been proposed as a promising solution to overcome the volume expansion and the flowing fracturing problems of the micron-size particles. Thus, various nanoparticles and nano-objects (0D, 1D, 2D and 3D) have been tried for the Li battery anode in the last decade.1, 2 It has been demonstrated that Si-NPs smaller than 150 nm can be avoided the further fracturing upon the repeating lithiation.
We propose a technology for preparations of novel Si-NPs/carbon(Si/C) composites on the basis of thermal shock of the carbon materials such as natural and artificial graphites. We developed a facile, one-step carbothermal shock method for transformations from micro-Si to Si-NPs less than 150 nm size and well dispersed on carbon matrix (Figure 1.). The particle size distribution of the Si-NPs was narrow and the dispersion was uniform. The Si/C composite anode exhibited a high specific capacity (>1,000 mAh/g) and predominant fast charging behavior.

Reference

[1] R. Chen, T. Zhao, X. Zhang, L. Li and F. Wu, Advanced cathode materials for lithium-ion batteries using nanoarchitectonics, Nanoscale Horiz., 2016, 1, 423-444
[2] D. Ma, Z. Cao and A. Hu, Si-Based Anode Materials for Li-Ion Batteries: A Mini Review, Nanomicro Lett., 2014, 6(4), 347-358
Figure 1. SEM images of Si-NPs/carbon (Si/C) composites

Figure 1
Hydrogen Storage on Nanoporous Carbon Foam for Electrochemical Applications
Authors: Kusdhany Muhammad Irfan Maulana , Li Hai-wen , Mufundirwa Albert , Sasaki Kazunari , Hayashi Akari , Lyth Stephen Matthew 
Published: December 2020

To be able to mitigate the threat of climate change, we need an alternative to fossil fuels. The use of hydrogen in fuel cells is an ideal candidate because hydrogen can be produced in many different ways and has a high energy density. However, one challenge in using hydrogen as a fuel is its storage. Storing hydrogen as compressed gas typically requires large pressures to meet US Department of Energy (DOE) targets, which leads to large losses during compression. By using solid state storage, we can use lower pressures for storage. Of the different kinds of solid state storage, physisorption on carbon materials has great potential because of its fast kinetics, reversibility, and the cost effectiveness of carbon materials.
In this research, we investigate the storage of hydrogen gas through physical adsorption on a sodium ethoxide-derived carbon foam. This carbon foam has all the necessary requirements of a good hydrogen sorbent: very large surface area and a large micropore volume. This material is also easy to synthesize: sodium ethoxide is pyrolyzed in N2 to make carbon, which is then washed in DI water and vacuum filtered. Unlike many other high surface area carbon materials, this carbon foam does not require a two-step carbonization-activation process, nor does it require a sacrificial template. This means it is more scalable and energy efficient compared to other synthetic carbon materials. [1,2]
The hydrogen adsorption capability of this material is tested at both 77K and 298K at elevated pressures (up to 9.5 MPa). Both the excess hydrogen uptake and the total hydrogen uptake are discussed. The values obtained are comparable with benchmark materials such as MOF-5 and IRMOF-20, which have 8 wt% and 10 wt% total uptake at 10 MPa, respectively, [3] and could plausibly meet US DOE targets for light duty vehicle application (5.5 wt% total uptake) at a much lower pressure than conventional compressed gas storage (usually 70 MPa). This work shows the potential of nanoporous carbon materials such as ours to work as a new storage system or as a ‘range extender’ of sorts for existing fuel cell vehicles.
[1] Lyth, S. M., Shao, H., Liu, J., Sasaki, K., and Akiba, E., 2014, “Hydrogen Adsorption on Graphene Foam Synthesized by Combustion of Sodium Ethoxide,” Int. J. Hydrogen Energy, 39(1), pp. 376–380.
[2] Choucair, M., and Mauron, P., 2015, “Versatile Preparation of Graphene-Based Nanocomposites and Their Hydrogen Adsorption,” Int. J. Hydrogen Energy, 40(18), pp. 6158–6164.
[3] Ahmed, A., Seth, S., Purewal, J., Wong-Foy, A. G., Veenstra, M., Matzger, A. J., and Siegel, D. J., 2019, “Exceptional Hydrogen Storage Achieved by Screening Nearly Half a Million Metal-Organic Frameworks,” Nat. Commun., 10(1), pp. 1–9.