bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbon Aerogels Electrodes for Energy Storage Applications
Authors: Parra-Puerto Andres , Rubio-Garcia Javier , Markiewicz Matthew , Zheng Zhuo , Kucernak Anthony 
Published: December 2020

Resorcinol – Formaldehyde Carbon Aerogels (CAGs) with different microstructure properties are very interesting materials for energy storage applications [1]. By changing the molar ratio between resorcinol and catalyst, and varying the resorcinol concentration, it is possible to change the density, mesoporosity and microporosity of the aerogels [2]. In this work we synthesize a number of materials with different properties and test their performance in an all Vanadium RFB.
The BET analysis showed a total surface area between 643 to 931 m2 g-1 and a variation of deposition morphology. The best performing material did not have the highest surface area, but instead had a good balance between microporous and external surface area (about 50:50), and on the macroscopic scale had sufficiently large pores to allow efficient electrolyte permeation. In contrast although the poorest electrodes had the highest surface areas, they had poor macroscopic porosity leading to large mass transport loss. The best performing electrode achieved a power density of 706 mW cm-2 at 1 V. This electrode was cycled at two different current densities for 20 cycles, achieving a battery efficiency between 75 to 80 % [3].

References

[1] J. Biener et al., “Advanced carbon aerogels for energy applications,” Energy Environ. Sci., vol. 4, no. 3, p. 656, Mar. 2011, doi: 10.1039/c0ee00627k.
[2] A. M. Elkhatat and S. A. Al-Muhtaseb, “Advances in tailoring resorcinol-formaldehyde organic and carbon gels,” Adv. Mater., vol. 23, no. 26, pp. 2887–2903, 2011, doi: 10.1002/adma.201100283.
[3] A. Parra-Puerto, J. Rubio-Garcia, M. Markiewicz, Z. Zheng, and A. Kucernak, “Factors Leading to Optimum Carbon Aerogel Based Electrodes for Redox Flow Batteries.” In Preparation

Figure 1
Operando Small-Angle Scattering Investigation of the Lithium/Sulfur Battery - Are Structural Features of the Nanocarbons Important?
Authors: Hark Eneli , Risse Sebastian , Kent Ben , Müller Rafael , Ballauff Matthias , Lu Yan 
Published: December 2020

Great deal of studies have been focused on the energy conversion and storage devices [1,2]. Among them, lithium/sulfur battery (Li/S) with the high gravimetric energy density (~730.0 Wh/kg) and affordability (sulfur is an earth-abundant element) [1]. Targeted research could promote the commercialization of Li-S batteries in a more efficient way and keep up with challenges for building continual batteries in terms of performance and energy density, which are greatly influenced by the multi-phase interfacial reactions, polysulfide equilibria and shuttling as well as by the electrolyte decomposition under the operating conditions [1,2].
In presentation, we will present recent work on Li/S batteries in two parts: First part is related to studies of the carbonaceous materials used as cathodes in these systems. The well-tailored carbons as the sulfur hosts in Li/S batteries could be used to prevent low sulfur utilization, therefore the model-free analysis by small-angle x-ray scattering in order to obtain reliable data on the internal surface area and the average pore size will be discussed [3].
The morphological and porous features of carbons can be extremely modified when they are processed in real electrochemical conditions. Thus, in a second part we will present the simultaneous performance of several independent techniques: small-angle neutron scattering (SANS) (heatmap of the Li/S during the galvanostatic cycling), electrochemical impedance spectroscopy (EIS), galvanostatic/potentsiostatic cycling of the Li/S test cell [4]. A nanoporous and binder-free carbon electrode was applied as a model electrode for further in situ/operando analysis, which is deemed of great importance for mechanism study of batteries.
The structural characterization of the nanocarbons is a crucial step towards better understanding the elucidation of structure-property-relationships which in turn will shed light on the processes occurring in complex in Li/S battery systems and helps to design cost-effective, safe batteries with preferably high capacities and longer lifetime over many cycles. A key structural features of nanocarbons and operando Li/S analysis will be the subjects of a presentation. Results obtained by in situ/operando SAS techniques are scientifically interesting and technologically very relevant for electrochemical applications.
[1] G. Li, Z. Chen, J. Lu, Chem 4, 2018, 3–7.
[2] A. El Kharbachi, O. Zavorotynska, M. Latroche, F. Cuevas, V. Yartys, M. Fichtner, Journal of Alloys and Compounds 817 (2020) 153261.
[3] E. Härk, A. Petzold, G. Goerigk, S. Risse, I. Tallo, R. Härmas, E. Lust, M. Ballauff. Carbon 146 (2019) 284-292.
[4] S. Risse, E. Härk, B. Kent, M. Ballauff, ACS Nano 13 (9) (2019) 10233-10241.

Figure 1
Corrosion Resistance of Electrochemically Exfoliated Doped-Graphene Nanostructures
Authors: Lopez Pablos Maria , Roberts Edward P.L. 
Published: December 2020

Graphene with its high conductivity and accessible surface area makes it an ideal material applicable as an adsorbent that can be electrochemically regenerated and reused over several cycles. However, it has been reported that corrosion causes degradation, weight loss and lifetime reduction of these adsorbents [1]. Most studies on corrosion mechanism in carbon materials has focused on highly porous and disordered materials used as catalyst supports for fuel cell electrodes. However, little work has been done to identify the corrosion mechanism in doped-graphene materials. The current study analyzes the corrosion resistance by using an accelerated corrosion protocol on electrochemically synthesized graphene samples with different doped heteroatoms including nitrogen and phosphorus. The accelerated corrosion protocol consisted of a potential steps whereby graphene was exposed to high potential for a few seconds for carbon corrosion to occur [2]. The corrosion mechanism and the degree of oxidation of the doped-graphene materials were characterized using cyclic voltammetry (CV), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Electroactive groups, changes in the double layer capacitance, and morphological changes were identified using these techniques. The stability of samples was determined for different samples using the accelerated corrosion test. Interestingly, the peaks associated with electroactive oxygen-containing surface groups were present and showed the extent of corrosion for both graphene samples before and after the test. A higher degree of corrosion was observed from the phosphorus doped-graphene as compared to the nitrogen-doped graphene. This was further confirmed from the corrosion current and percentage change in gravimetric capacitance. The implication of these findings suggest that the large distortion caused by the additional P-doping in the carbon lattice allows open edge sites and produces wrinkles [3]; thus providing more defective sites and facilitating corrosion. Further materials analyses are ongoing to fully elucidate this process in detail and support the results obtained from the electrochemical tests.
References
[1] F. Sharif, L. R. Gagnon, S. Mulmi, and E. P. L. Roberts, “Electrochemical regeneration of a reduced graphene oxide / magnetite composite adsorbent loaded with methylene blue,” Water Res., vol. 114, pp. 237–245, 2017.
[2] F. Forouzandeh, X. Li, D. W. Banham, F. Feng, S. Ye, and V. Birss, “Understanding the Corrosion Resistance of Meso- and Micro-Porous Carbons for Application in PEM Fuel Cells,” J. Electrochem. Soc., vol. 165, no. 6, pp. F3230–F3240, 2018.
[3] C. H. Choi, S. H. Park, and S. I. Woo, “Binary and ternary doping of nitrogen, boron, and phosphorus into carbon for enhancing electrochemical oxygen reduction activity,” ACS Nano, vol. 6, no. 8, pp. 7084–7091, 2012.

Figure 1
Green Synthesis of Nickel Borides Supported over Multiwall Carbon Nanotube As a Novel Catalyst for Hydrogen Evolution
Authors: Quach Qui , Phillips Erin , Biehler Erik , Abdel-Fattah Tarek M 
Published: December 2020

The use of non-renewable fuels such as coal, oil, and natural gas significantly affects ecological system and human health. A substantial effort has been spending to find an eco-friendly and efficient energy source. Hydrogen appears as a green energy source which emits water as its byproduct during the combustion. The primary concern of hydrogen fuel is its dependence on fossil fuels in the production. Hydrogen feedstock material like Sodium borohydride (NaBH4) becomes potential, alternative source for manufacturing hydrogen fuel. However, the reaction between NaBH4 and water was slow and required a durable catalyst 1,2,3. The synthesis method of some catalysts is often expensive and require the use of various toxic chemicals4. The purpose of this study was to discover a green method of synthesizing nickel borides composite (NiB@MWCNT) and to utilize it in enhancing hydrogen generation reaction. The composite was synthesized from supported nickel metal organic framework (Ni-MOF-5) in the presence of Multiwalled Carbon Nanotube (MWCNT). The structure and composition of NiB@MWCNT was determined by Powder X-Ray Diffraction (PXRD), Scanning Electron Mircroscopy (SEM, Figure 1), Energy Dispersive X-Ray Spectroscopy (EDS), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). The catalytic efficiency of NiB@MWCNT was tested at temperatures of 281K, 295K, and 303K. The temperature trials indicated the activation energy was 43 kJ mol-1. NiB@MWCNT also showed a steady hydrogen generation of 44.4 ml through the reusable test.
References:

T. Dushatinski, C. Huff, and T. Abdel-Fattah, Applied Surface Science, 385, 282 (2016).

C. Huff, J. M. Long, A. Heyman, and T. Abdel-Fattah. Applied Energy Materials, 9, 4635-4640 (2018)

C. Huff, J. M. Long, A. Aboulatta, A. Heyman, and T. Abdel-Fattah, ECS Journal of Solid State Science and Technology, 10, M115-M118 (2017)

Y. Huang, Y. Wang, R. Zhao, P. Shen, and Z. Wei. International Journal of Hydrogen Energy. 23. 7110-7115 (2008).

Figure 1. SEM imaging of NiB@CNT at 50 micrometer scale

Figure 1
Solution Plasma Synthesis of B-Doped Graphene Derivatives with Enhanced Photocatalytic Properties
Authors: Wang Xiaoyang , Chae Sangwoo , Saito Nagahiro 
Published: December 2020

At present, human beings are facing two major problems: energy crisis and environmental pollution. Massive anthropogenic emissions of carbon dioxide (CO2) associated with increased consumption of fossil fuels have contributed to global warming and the energy crisis. The photocatalytic CO2 reduction (PCCR) to solar fuels such as methane, methanol and carbon monoxide is considered to be one of the best solutions to solve these problems. In recent years, with the invention of graphene and its derivatives, heterographene photocatalytic materials have become the focus of attention, especially for the development of photocatalysts and the application of photocatalysis. Heterographene and its derivatives can overcome the limitations of traditional photocatalysts, due to their excellent physicochemical and electrical properties like high specific surface area, stability, corrosion resistance, photosensitivity, and electrical conductivity. Therefore, heterographene-based photocatalysts could be a viable strategy to break new grounds in the area of PCCR to useful chemicals/fuels, i.e. converting sunlight to fuels. The current methods for the synthesis of heterographene are complex or harsh conditions, so it is urgent to develop new methods for the synthesis of doped graphene. In this study, the B-doped graphene derivatives were synthesized for PCCR by solution plasma (SP), which can provide us a rapid synthesis at room temperature and atmospheric pressure.
Acknowledgements
This work was financially supported by JST-OPERA (JPMJOP1843), JST-SICORP (JPMJSC18H1) and JSPS-KAKENHI (JP18K18998).
Development of Screen-Printed Impedance Sensor and Detections of Wiring Corrosion and Dew Condensation
Authors: Mouri Masahiro , Hoshi Yoshinao , Watanabe Hikari , Shitanda Isao , Itagaki Masayuki 
Published: December 2020

The pitch of wiring on printed circuit boards has become finer for the development of small and lightweight electronic devices. Due to the finer pitch of wire, dew condensation causes a short circuit of wiring easier and there is a risk of breaking the wiring due to slight corrosion. It is crucial to develop a sensor for monitoring dew condensation and corrosion of wiring in order to prevent these corrosion phenomena. Our group 1) has developed a corrosion monitoring sensor with screen printing techniques. This sensor, which has a comb-like structure of silver wiring on the boards, can monitor dew condensation environments using electrochemical impedance spectroscopy (EIS) because of the change of impedance spectra with condensation condition. Aiba 2) et al. have fabricated printed –type corrosion monitoring sensor which can evaluate amount of dew condensation. This sensor, which has wiring of a reference resistance by coating anticorrosion, can quantitatively evaluate dew condensation by standardizing the output impedance from the sensor with reference resistance. In this study, monitoring corrosion sensor that can accurately detect corrosion of wiring and dew condensation was developed using screen printing.
Polyimide was used for a substrate of the developed sensor, and silver wiring was printed on the substrate by using screen printing. The silver wiring consists of two parts. The upper and lower parts have comb-like structure and two parallel straight lines, respectively. Corrosion of wiring and dew condensation can be detected by the upper and the lower patterns, respectively. UV irradiation was performed for 10 minutes in an oxygen atmosphere only on the substrate to make hydrophilic partially.
Dew condensation on the surface of the corrosion sensor was detected by measuring impedance spectra. The measurements were performed in the chamber that temperature and the relative humidity were set at 25 ℃ and 90 %, respectively. The frequency range of impedance measurements were from 10 mHz to 10 kHz. The amplitude of voltage modulation for the sensor was 10 mV. The voltage during the measurements was set at 0 V.
In impedance spectra of the sensor without UV ozone treatment, although dew condensation occurred, the wiring did not short circuit and impedance spectrum remained on the real number axis. On the other hand, in impedance spectra of the sensor with UV ozone treatment, impedance spectrum of capacitive semicircle attributed to short circuit of wiring due to dew condensation was observed, that is, it was possible to detect dew condensation with high sensitivity.

References

I. Shitanda, A. Okumra, M. Itagaki, K. Watanabe, Y. Asano, Sensor Actuat B-Chem, 139, 292 (2009).

A. Aiba, N. Fujii, Y. Hoshi, I, Shitanda, M. Itagaki, J. Electrochem, Soc., 165, C743 (2018).
Plasmonic Platinum-Titania Photocatalyst Nanocomposite for Solar Application and Protective Titania Modified Nanocomposite Resin Coatings Against Steel Corrosion
Authors: Eduok Ubong 
Published: December 2020

In the study, two main applications of titania nanocomposites are presented; solar application and corrosion protection. A chemical protocol for preparing a unique platinum-titania photocatalyst via solvothermal chemical reaction. This process utilized chloroplatinic acid hexahydrate and titanium butoxide as precursors in the presence of dimethyl sulfoxide. Synthesis was followed by morphological and crystalline structural characterizations as well as nanoparticle size distribution. Optical investigations revealed optical responses after UV-induced excitation. This photocatalyst also revealed photodegradation of diuron (a model algicide) and improved performance for photodecomposition after an hour. This composite also exhibited a defined self-cleaning ability when incorporated within fabrics.
For long-term performance in outdoor applications, compatible inorganic fillers with reliable corrosion inhibiting abilities are incorporated within acrylic coatings for metallic structures susceptible to atmospheric degradation. However, challenges still abound on the selection criteria for appropriate fillers suitable for most coatings, from both inorganic and organic pools. In this work, titania nanoparticles (TiO2NPs) were prepared from titanium ethoxide via sol-gel technique. Titania-modified acrylic resins were subsequently synthesized by incorporating TiO2NPs within different grams of an acrylic base resin. In-depth characterization has been conducted for both prepared TiO2NPs and the synthesized titania modified acrylic coatings. The inorganic/organic hybrid resin coating was applied on mild steel to prevent its corrosion in 5 wt% NaCl solution. The presence of TiO2NPs within these acrylic coatings further blocked inherent pathway to which corrosive ions and molecule could have permeated the coating; hence, delaying steel corrosion. The optimum amount of TiO2NP fillers required to prepare an anticorrosion acrylic resin coating with efficient barrier properties has been identified.
These particles further strengthened the gross mechanical properties of the coatings in terms of bulk structural reinforcement while also enhancing their barrier performances. This work highlights the correlation between coating content and the failure mechanisms or loss of corrosion resistance of degrading acrylic coatings in saline medium. These modified acrylic resin coatings may have a future as solar and outdoor protective coatings.

Keywords: Platinum-titania photocatalyst; Titania nanoparticles; Acrylic resin coatings; Protective coatings; Corrosion; Solar.
Oxidation Behavior of Additively Manufactured 316L in a Supercritical CO2 Environment
Authors: Schaller Rebecca Filardo , Melia Michael Anthony , Bocher Florent 
Published: December 2020

The general properties of additively manufactured (AM) metals have been fairly well characterized to this point with respect to mechanical behavior and even general corrosion response. However, as the fields of application of AM metals broadens, the need for unique/specialized evaluation is required. For instance, there remains a lack in understanding how AM metals behave under atmospheric corrosion exposure conditions where local heterogeneous environments govern the surface reactivity and susceptibility. Similarly, knowledge gaps exist in specialized environment, for example supercritical CO2 (sCO2). Materials and environment parameters such as composition, pressure, and temperature will influence corrosion susceptibility and/or oxidation properties. As AM metals often display vastly different microstructures from their wrought counterparts due to non-equilibrium cooling during processing, an understanding of their behavior in these environments is critical prior to possible application. Additionally, typical engineering design of oxy-combustion gas turbine systems used in these environments, results in atypical conditions, usually localized, that are well known to affect environmental performance of materials (such as crevices, welds, residual stresses, or galvanic coupling).
Austenitic stainless steel, type 316L, specimens made by selectively laser melting (SLM) were exposed with their traditional wrought counterparts for comparison at 450°C and 7.6 MPa in pure sCO2 for one week. SLM samples were exposed in the as printed (a contour scan strategy was used) and the ground (ground to 1200 grit) state and compared to wrought samples ground to 1200 grit. Prior to exposure, samples were partially coated with a zirconia film to establish an initial true height to aid ellipsometry. Post exposure, oxide film thickness was measured with respect to the non-reactive coating height. Preliminary analysis of oxide film thickness measurements performed using ellipsometry showed a thinner oxide film grown on the in-process polished SLM samples (0.66 - 0.79 µm) versus the ground SLM (1.1 µm) or wrought samples (0.8 – 1.22 µm). Additional analysis was performed through scanning electron microscopy and focused ion beam combined with transmission electron microscopy to characterize the oxides formed and elucidate possible microstructural and/or morphological dependence of the film growth.
SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. SAND2020-4568 A
Diffusivity of Oxygen in Yttrium Silicates Estimated By Using High-Temperature Oxidation of Their Composites Dispersed with SiC Particles
Authors: Nanko Makoto , Dinh Vu Huy 
Published: December 2020

Yttrium silicates, Y2SiO5 and Y2Si2O7, have been studied as candidate materials for the environmental barrier coating (EBC) system on SiC/SiC composites for advanced gas turbine blades because of low oxygen permeability, low volatility in steam conditions, and comparable thermal expansion with SiC/SiC composites. In order to design the EBC system, diffusion properties of yttrium silicates are important. In this work, diffusivity of oxygen in yttrium silicates is estimated by using kinetics of high-temperature oxidation of their composites dispersed with SiC particles. Assuming oxidation of SiC particles dispersed in yttrium silicates is promoted mainly with inward diffusion of oxygen, diffusion of oxygen in yttrium silicates can be estimated. Y2SiO5 powder was synthesized by using the solid-state reaction technique with Y2O3 and SiO2 powders at 1400ºC for 20 h in air. Y2Si2O7 powder was prepared with the solid-state reaction process from powder mixture of Y2O3 and SiO2 at at 1500ºC for 24 h in air. Densified bulks of yttrium silicates dispersed with 5 vol% SiC particles were obtained with the pulsed electric current sintering of powder mixture of yttrium silicate and SiC. The bulk samples were oxidized at 1300ºC in air. Depth of the zone in which SiC particles are oxidized was measured by observing the cross-section with scanning electron microstructure. Thickness of the oxidized zone obeys the parabolic law. In the both cases, the oxidation product layers were not observed significantly on the surface of the composites after high temperature oxidation. These results mean that outward diffusion of Y or Si did not occur significantly for oxidation of SiC dispersed in the yttrium silicates. That is, the oxidation of the SiC dispersoid was conducted with inward diffusion of oxygen. Diffusion coefficient of oxygen in yttrium silicates can be obtained as shown in Table 1. The value for Y2SiO5 is larger than that for Y2Si2O7. This fact means that the protection performance of oxygen diffusion on Y2Si2O7 is better than that on Y2SiO5 for the EBC applications.
Table 1 Diffusion coefficients of oxygen in yttrium silicates at 1300°C.

Y2SiO5

Y2Si2O7

D
O/ m2s-1

2.8×10-16

1.3×10-18
Priority COVID-19 Vaccination for Patients with Cancer while Vaccine Supply Is Limited
Authors: Ribas Antoni , Sengupta Rajarshi , Locke Trevan , Zaidi Sayyed Kaleem , Campbell Katie M. , Carethers John M. , Jaffee Elizabeth M. , Wherry E. John , Soria Jean-Charles , D'Souza Gypsyamber 
Published: December 2020

AbstractSummary:Published series on COVID-19 support the notion that patients with cancer are a particularly vulnerable population. There is a confluence of risk factors between cancer and COVID-19, and cancer care and treatments increase exposure to the virus and may dampen natural immune responses. The available evidence supports the conclusion that patients with cancer, in particular with hematologic malignancies, should be considered among the very high-risk groups for priority COVID-19 vaccination.