bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalytic Activity of Gold Nanoparticle Functionalized Carbon Nanotubes for a Hydrogen Evolution Reaction
Authors: Abdel-Fattah Tarek M , Huff Clay , Dushatinski Thomas 
Published: February 2020

Hydrogen gas is an attractive alternative to carbon-based fuels because of its green byproducts of combustion, and its renewable nature [1]. Dihydrogen can be evolved from water, but the energy produced from burning will only match the energy expended to produce the gas. Further, the inability to reach 100% efficiency in fuel cells or combustion engines further reduces the usable energy produced. These limitations require better means of producing hydrogen gas. Solid storage materials are being researched as a possible solution to the problems presented not only by the energy costs of evolving hydrogen gas, but also the pressurized storage a gaseous fuel requires. Metal hydrides are known for their hydrogen releasing capacities, content of readily available chemical compounds. Sodium borohydride (NaBH4) has the highest hydrogen content by weight and is the most produced in the largest quantities of metal hydride materials. The oxidation of aqueous NaBH4 is a slow process, but ultimately liberates 4 moles of dihydrogen per mole of NaBH4. Many catalysts have been implemented in this reaction such as Ni materials, but these catalysts suffer from oxidation degradation [2-3]. Despite their cost, they also offer significantly higher surface area than bulk films and can be functionalized with many different species, often offering stability to the absorbed species.
Catalytic activity of the produced Au-MWCNT composites was tested in an aqueous NaBH4 hydrogen evolution reaction. The evolved gas was measured through the use of a water-displacement system, Ohaus microbalance, and mass logging software. The Au-MWCNT composite greatly outperformed the original MWCNT, but only when precursor solution of suspended MWCNTs and Au-nanoparticles was stirred. When the precursor was sonicated, the films showed a much lower catalytic activated, worse than the original MWCNTs. It can be inferred that the sonication caused damage to the MWCNTs, and thus that stirring is a better preparatory technique for the composites.

Catalytic Surface

Rate Constant (10-3 min-1)

Au-MWCNT stirred
8

Au-MWCNT sonicated
5.5

MWCNT
5.8

References:

Schlesinger, H.; Brown, H.; Finholt, A.; Gilbreath, J.; Hoekstra, H.; Hyde, E. Sodium Borohydride, Its Hydrolysis and its Use as a Reducing Agent and in the Generation of Hydrogen. 1952,
J. Am. Chem. Soc. 75(1) 215-219

Chinnappan, A.; Kang, H.; Kim, H. Preparation of PVDF nanofiber composites for hydrogen generationfrom sodium borohydride. 2011,
Energy 36(2) 755-759
Scalable Conversion of Carbon Dioxide into Graphene for Electrochemical Energy Storage
Authors: Li Chen , Zhang Xiong , Ma Yanwei 
Published: February 2020

Graphene materials are regarded as one promising candidate for next-generation electrochemical energy storage devices due to its unique properties, such as high specific surface area and electrical conductivity. However, most of the up-to-date methodologies for producing graphene, such as chemical vapor deposition, mechanical exfoliation and reduction of graphite oxide, involve several severe drawbacks including heavy ion pollution, low yield and labor-intensive processes, which raise the cost and limit the scalability of graphene production. Therefore, a facile and cost-saving pathway for high-quality graphene synthesis is urgently needed.
Combustion of fossil oil still represents a major energy source for electricity generation around the world, which releases a tremendous amount of CO2 to cause detrimental global warming. As a result, a prospective method for graphene production is to use the available CO2 as feedstock gas. But due to the inherent chemical stability of C=O bond, it is a great challenge to reduce CO2 into carbon materials by conventional techniques. It is well-established that magnesiothermic reaction is capable of dissociating strong chemical bonds, which offers a potential way for effective utilization of CO2.
Herein, we present an ultra-fast magnesiothermic reaction to fabricate few-layer graphene with highly developed mesoporosity from CO2 and magnesium/magnesium oxide mixture. It is demonstrated that magnesium oxide acts as the crucial template to guide graphene formation and provide mesopores after acid rising. The ordered mesoporous graphene exhibits a high specific surface area of 709 m2 g-1 and a narrow pore size distribution around 4 nm.
We further confirm its excellent electrochemical performance as supercapacitor electrodes. In IL electrolyte, the specific capacitance of MSG is as high as 260 F g-1 at 2 A g-1, corresponding to an energy density of 135.6 Wh kg-1, and can still maintain 173 F g-1 at an ultra-high rate of 100 A g-1. This excellent rate capability performance gives birth to an unprecedented power density of 7684 kW kg-1. Moreover, the electrochemical stability is demonstrated by a high capacitance retention of 90% after 1 million cycles of rapid charge/discharge at 100 A g-1. We believe our present work will give a new insight into the production of high-quality graphene materials.
Fig. 1 Ordered mesoporous graphene prepared by ultra-fast magnesiothermic reaction

Figure 1
Heterojunction Diodes Comprising Nitrogen-Doped Ultrananocrystalline Diamond/Hydrogentad Amorphous Carbon and p-Type Silicon
Authors: Zkria Abdelrahman , Yoshitake Tsuyoshi 
Published: February 2020

Ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films, wherein diamond crystallites with diameters of less than 10 nm are embedded in an a-C:H matrix, have a large absorption coefficients of 105 - 106 cm-1 in the photon energy range between 3 and 6 eV that make them applicable to optoelectronics devices. Moreover, the realizations of p-type and n-type diamonds are desirable for the applications of diamond-based electronic devices. In this work, the heterojunction diodes comprising nitrogen-doped UNCD/a-C:H and p-type Si were fabricated by coaxial arc plasma deposition (CAPD) and the heterojunction parameters were evaluated from the current–voltage (IV) and capacitance–voltage (CV) measurements carried out in dark at room temperature. Furthermore, the photodetection performance was studied.
Experimentally, n-type UNCD/a-C:H films were deposited on p-type silicon substrate at a substrate temperature of 550 ºC with ambient pressure of 53.3 Pa. the Pd electrode is deposited on both sides by using of Radio Frequency (RF) sputtering. The (I–V) characteristics of the diodes measured in the dark . I-V curve exhibited a rectiﬁcation ratio of more than 104, which evidently confirms that nitrogen-doped UNCD/a-C:H possesses n-type conduction and easily forms junction with p-type semiconductor.

C–V measurements of the diode confirm junction formation, in which capacitance non-linearly decreases with increasing reverse bias voltage. The built-in potential of the heterojunction was estimated to be 0.68 eV from the extended linear part of 1/C2 plot. From the slop of 1/C2, carrier concentration of the UNCD/a-C:H film was estimated to be 6×1015 cm-3. Here, carrier concentration of Si substrate was 1×1015 cm-3 for the ﬁtting analysis. The value of depletion region width 𝑊UNCD in the UNCD/a-C:H ﬁlm was estimated to be 200 nm at the reverse voltages of ±1 V, which is close to that value generally measured for heterojunctions with closed ranges of carrier concentrations. More details will be explained in presentation during the conference.
Enhanced Formation of Carbon Microcoils Having Different-Sized Ni Catalyst By Different Injection Gas Sequence
Authors: Kang Gi-Hwan , Kim Sung-Hoon , Park Sangmoon 
Published: February 2020

Carbon microcoils were synthesized using C2H2 flow as a source gas along with an initial short time (5 min) SF6 flow as an incorporated additive gas under the thermal chemical vapor deposition (CVD) system. Different interruption/injection of C2H2 or SF6 flow and different injection sequences of the gas flow were applied while maintaining the identical overall injection time of C2H2 and/or SF6 flow. Indeed, the injection sequence of C2H2 or SF6 flow was manipulated according to the different-sized Ni catalysts, namely small (~ 0.1mm) or large (~100 mm) size in diameter. In the case of the small-sized Ni catalyst, the formation of the carbon microcoils could be well-developed under the injection sequence of SF6 flow → C2H2 flow. In the case of the large-sized Ni catalyst, on the other hand, the injection of C2H2 flow prior to the injection of SF6 flow promotes the formation of carbon microcoils. Based on these results we revealed the role of C2H2 flow injection or SF6 flow injection with the different-sized Ni catalyst for the enhanced formation of carbon microcoils. Finally, we suggest the growth mode of carbon microcoils with the different-sized Ni catalyst.
Development of the Negative Electrode Using Coin-Stacked CNF for Li Ion Battery
Authors: Shimizu Akihiro , Oda Hirokazu , Nakagawa Kiyoharu 
Published: February 2020

In general, graphite materials are used for the negative electrode material for lithium-ion batteries (LIBs). Charge/discharge mechanism of LIBs occurs by Li ion intercalation/deintercalation into/from graphite layers. More high-performance LIBs have been demanded for usage as a power source such as electric vehicles.
We focused on the structure of carbon nanofilaments (CNF). The diameter of CNF is very small compared to graphite. CNF has a similar layered structure with graphite. Three distinct structure types of CNF has been identified based on the angle of graphene layers with respect to the filament axis, coin-stacked, cup-stacked, and tubular. CNF has remarkable electronic properties and many other unique characteristics. For this reason, CNF has received much attention. Therefore, in this study, we investigated that coin-stacked CNF (CSCNF) was synthesized by the chemical vapor deposition (CVD) method, and CSCNF negative electrode for LIBs was evaluated.
For CNF synthesis, nano metal particles loaded on oxidized diamond were used. Oxidized diamond has oxygen-containing functional groups arranged regularly. Therefore, nano metal particles is a highly dispersed on it. Pd metal was used for loaded metal. Pd metal could synthesized CNF having coin-stacked structures. Pd metal was loaded on oxidized diamond by metal nano-colloidal method. C2H4 as a feedstock for CSCNF was used.
Synthesized CSCNF was used for the negative electrode material. Electrochemical properties of the negative electrode were evaluated half-cell test. Half-cell was assembled in a glove box under an argon atmosphere. Oxidation-reduction reaction of the negative electrode was evaluated by cyclic voltammogram (CV) measurement. Capacity of the negative electrode was evaluated by a constant current charge and discharge (CC) measurement. CV and CC measurement were observed that CSCNF had a different discharge behavior as compared to graphite. Electrochemical measurements indicated that CSCNF negative electrode displayed discharged capacity (514 mAh/g) over the theoretical discharged capacity of graphite intercalation compounds (372 mAh/g). From the results, it seems that Li ion was intercalated into CNF layers and adsorbed on the surface of CNF. For this reason, adsorption of Li ion was gained high capacity of the negative electrode with CNF. The negative electrode with CNF was thus found to be appropriate materials for the use in LIBs.
Tribocorrosion of Type 316L Stainless Steel with Nanopore Arrays in Stimulated Body Fluid
Authors: Toji Chisato , Miyabe Sayaka , Tsuchiya Hiroaki , Fujimoto Shinji 
Published: February 2020

Type 316L stainless steel is widely used as a biomaterial because of high corrosion resistance owing to the passive films that form spontaneously on the surface. However, if the passive films are broken by mechanical damages corrosion will be accelerated in the body, resulting in the failure of the integrity.
Wear causes the breakdown of passive films, which accelerates corrosion of metallic implant, as a result so-called tribocorrosion is induced. In order to suppress tribocorrosion, friction between materials should be well-controlled. For the control of friction, various surface treatments have been reported. Recently we reported the formation of nanopore arrays on Type 316L stainless steel by a simple anodization.In the present work, we examined tribocorrosion of Type 316L stainless steel with nanopore arrays in simulated body fluid.
The tribocorrosion of Type 316L stainless steel was examined in pin-on-disk wear test. UHMWPE (ultrahigh molecular weight polyethylene) and Type 316L stainless steel were used as a pin and disk materials, respectively. Two different surface morphologies were prepared for the disk of the stainless steel; mirror and nanopore arrays. The nanopore arrays were formed by anodization in an ethylene glycol containing sodium perchlorate. The pin-on-disk wear test was carried out in 0.9% NaCl solution or 30% FBS (fetal bovine serum) at 37 °C. During the test, the friction coefficient and the corrosion potential of the disk specimen were monitored simultaneously with time.
The corrosion potential decreased immediately after the test was commenced and then recovered gradually with time. After the test wear debris with the size of several micrometers was observed on the surface. In the presentation, the effects of surface nanostuture and organic components included in FBS on the tribocorrosion behavior of Type 316L stainless steel will be discussed.
Investigation of Anticorrosion Coatings for Iron Using Polyaniline By Electrochemical Impedance Method
Authors: Fujimatsu Ai , Aoki Atsushi 
Published: February 2020

<Introduction>The most efficient corrosion inhibitors are based on heavy metal such as Cr. However, the use of them has now been widely restricted by law due to environmental and toxicological issues. So recently, anticorrosion method with conducting polymer has attracted attention because of free heavy metal. The conducting polymer, polyaniline is known to have a number of molecular configurations by redox status and pH. Two half oxidized forms, protonated emerardine salt(ES) and deprotonated emerardine base(EB) change reversibly by acid-base processing. In order to investigate the anticorrosion mechanism of the iron plate coated by deprotonated polyaniline film, we investigate electrochemical characteristics by AC impedance technique in the different anion solutions. Moreover, native oxidation layer of bare iron is also investigated. The three models of the equivalent circuits are proposed to explain the anticorrosion mechanism of the iron plate coated by deprotonated polyaniline film.

<Experiment>The metallic samples used in this study were bare iron JISG3141, rolled steel plate. All metallic samples were degreasing with acetone. EB was dissolved in N-methyl-2-pyrrolidinone and that 5.0 mg/mL polyaniline(EB) solution was prepared. This solution was casted to iron plate on the hot plate at 60 °
C. This state was maintaining for 6 hours to get EB coating plate. All AC impedance measurements were conducted using three-electrode system. Working electrode is iron electrode, reference electrode is saturated calomel electrode and counter electrode is Pt coil electrode. Also, two electrolysis solutions, 1.0 M NaCl solution and 0.1 M Na2B4O7 solution were used to compare corrosion behavior by anion species.

[1] D. W. DeBerry, J.Electrochem.Soc., 132, 1022-1026(1985).
Electrochemical Conversion of CoSb3 in Various Acidic Electrolytes
Authors: Veys-Renaux Delphine , Drevet Richard , Petitjean Carine , Aranda Lionel , David Nicolas , Berthod Patrice 
Published: February 2020

CoSb3-based skutterudite compounds are promising thermoelectric materials thanks to a high figure of merit ZT. However their sensitivity to thermal degradation under oxidation mechanisms is a significant problem regarding their high operating temperature. A protective coating is therefore necessary. In this framework, the formation of an oxide conversion layer by surface anodizing represents an interesting alternative to PVD coatings usually considered.
In the present work, the electrochemical behavior of CoSb3 is studied over a large anodic voltage range (0 to 50 V) in three acids, i.e. phosphoric acid, oxalic acid and sulfuric acid at different concentrations (0.01 M to 1 M). Potentiodynamic polarizations performed on CoSb3 plates, in comparison with pure Co and pure Sb, reveal the possible formation of a passive layer between 1V and 3V, on a passivation plateau. Actually, below 3V, the electrochemical behavior of CoSb3 is similar to the behavior of pure Sb, whatever the electrolyte and the concentration. Beyond this potential, the current density rises on CoSb3 and stabilizes one order of magnitude higher. Regarding pure Co, it obviously undergoes dissolution as shown by the very high current densities reached.
The oxidation of CoSb3 at 2V in sulfuric and oxalic acids results in the growth of a conversion layer. According to SEM-EDS and DRX experiments, this coating is mainly made of amorphous antimony oxides (due to the high selective dissolution rate of cobalt in these media), constituting a porous (exfoliated) matrix. In the specific case of oxalic acid, sticks of crystallized oxalates (mostly antimony oxalate hydroxide but also cobalt oxalate hydroxide) are tangled between the oxide sheets.

Figure 1
Study of Micro-Scale Experimental Teaching Materials of Corrosion and Corrosion Protection for Maintenance Engineers
Authors: Ito Daisuke , Yokoyama Takashi , Okazaki Shinji 
Published: February 2020

In this study, micro-scale experimental teaching materials corrosion and corrosion protection has been developed, it was investigated the educational effect and its usefulness. Experimental program is shown below.
A. Basic experiment of Corrosion
1) Corrosion Observation
2) Confirmation of reaction on the iron surface
3) Observation of current caused by corrosion
B. Types of corrosion
4) Heterologous metal contact
5) Local corrosion under the sediments of rust
6) Influence of chloride ions on the corrosion of stainless steel
C. Mechanism of corrosion protection
7) Cathodic protection by galvanic anode system
8) Cathodic protection by the external power supply system

Figure 1
Nonflammable, Fast Charging & Superb Cycle Life Battery Technology For Automotive Applications
Authors: Liu Wenjuan 
Published: February 2020

Li-ion batteries are one of the most potential candidates as the energy storage devices mainly due to their high energy densities with fairly good rate capabilities and a fairly long cycle life. Currently, Lithium-ion batteries are nearing their theoretical energy density limit and battery manufacturers are beginning to focus on improving manufacturing methods and increasing safety. In this presentation, I will introduce Microvast’s non-flammable battery technology for lithium-ion batteries resolves battery safety issues through a multi-level approach from materials to the system level. The new technology takes both active and passive protection measures in order to enhance product safety, including improvements to the battery's electrolyte, separator and protection system. Meanwhile, the fast charging and superb cycle life are maintained for the automotive application. The nonflammable, fast charging & superb cycle life battery technology can solve the current key constraints in electric vehicle development and to redesign electric vehicle power systems to the mass adoption of electric vehicles.
Advanced Materials for Future Generations of Automotive Batteries: Potential and Limits
Authors: Lamp Peter 
Published: February 2020

New mobility concepts are required to balance the individual need for mobility and the sustainable utilization of natural resources as well as the protection of the environment. Technology improvements are necessary that allow the transition towards mobility concepts based on renewable energies. Today the electrification of drive trains, ranging from hybrid vehicles to plug-in hybrids, and finally to pure electric vehicles, is the commonly accepted next step in this direction. BMW is strongly committed to this path.
The electric energy storage is the key technology for electrification. Energy and/or power density of the storage system define the fuel reduction potential as well as the customer acceptance. To make it a success story, care has to be taken to fulfill the present and future customer expectations, in particular with regard to safety and reliability, performance and costs. One of the major factors for a high market penetration of electric vehicles is the ratio between driving range and costs. More than 90% of the world wide vehicle market falls in the price range below 50.000$; on the other hand, a driving range above 400 km is needed. That requires energy density targets above 250 Wh/kg or 400 Wh/l for a battery pack, with costs as low as 150 $/kWh.
Different strategies are nowadays considered which enable a considerable increase in the electric range. These include the optimization of cell and electrode design. But the largest impact on the energy density is the introduction of novel cathode and anode materials for Li-ion cells. There are a number of materials in development which may give an improvement in energy density. But only a few seem to have the potential to meet automotive requirements in particular regarding lifetime and safety. For most of the material developments considerable improvements are needed before a possible industrialization of the new generations of batteries for automotive application can be envisaged.
This presentation will outline the potential and limits of present material concepts from a car manufacturer point of view. In particular it will address open issues to be solved in the future development of electric energy storage technologies for automotive applications.
Conversion-Alloying Anode Materials for Lithium-Ion Batteries
Authors: Mueller Franziska , Bresser Dominic , Passerini Stefano 
Published: February 2020

Lithium-ion batteries, the most succesful power source for portable electronic devices, are emerging as the most promising energy storage devices for hybrid and, most likely, full electric vehicles. In our continuous efforts to develop high capacity, conversion-alloying anode materials for lithium-ion batteries,[1-4] we developed a new active material, Fe-doped SnO2 (Sn0.9Fe0.1O2, SFO), ideally characterized by low (de-)lithiation potential, high coulombic efficiency and long-term cycling stability. To the best of our knowledge, this is the first report on iron-doped tin oxide as active material for lithium-ion batteries. For battery applications, however, only one manuscript dealing with the utilization of molybdenum-doped SnO2 as active material for lithium-ion batteries was reported in 1999[5], i.e., prior to the first report on transition metal oxides as conversion materials by Poizot et al. in 2000.[6]

Within this study it is shown as doping SnO2 with Fe leads to significantly enhanced specific capacity, cycling stability, and coulombic efficiency. SFO-C offers, after ten cycles, a reversible specific capacity of 1519 mAh g-1, i.e., about twice that of pure SnO2, due to the presence of the dopant (Fe) favoring the reversible formation of lithium oxide and, thus, enabling the beneficial combination of lithium storage by alloying and conversion.

References:

1. D. Bresser, E. Paillard, R. Kloepsch, S. Krueger, M. Fiedler, R. Schmitz, D. Baither, M. Winter, S. Passerini, Adv. Energy Mater.
2013, 3, 513.
2. F. Mueller, D. Bresser, E. Paillard, M. Winter, S. Passerini, J. Power Sources
2013, 236, 87.
3. D. Bresser, F. Mueller, M. Fiedler, S. Krueger, R. Kloepsch, D. Baither, M. Winter, E. Paillard, S. Passerini, Chem. Mater.
2013, 25, 4977.
4. A. Varzi, D. Bresser, J. von Zamory, F. Mueller, S. Passerini, Adv. Energy Mater.
2014, 4, 1400054.
5. J. Morales, L. Sánchez, J. Electrochem. Soc.
1999, 146, 1640.
6. P. Poizot, S. Laruelle, S. Grugeon, L. Dupont, J.-M. Tarascon, Nature
2000, 407, 496.