bluuebunny/crossref_metadata_2025_split huggingface dataset:
First-Principles Investigation of the Effect of Interstitial Carbon on Corrosion Resistance of Martensitic Medium-Carbon Steel
Authors: Kadowaki Mariko , Saengdeejing Arkapol , Muto Izumi , Chen Ying , Masuda Hiroyuki , Katayama Hideki , Doi Takashi , Kawano Kaori , Miura Hideo , Sugawara Yu , Hara Nobuyoshi 
Published: February 2020

Martensitic carbon steels with fine grains are used for many industrial applications. Interstitial carbon provides high strength to martensitic structure. Although it has been reported that the interstitial carbon has the beneficial effect on the pitting corrosion resistance of steels,1,2 the role of interstitial carbon is still unclear. In this research, first-principles calculations were applied to the clarification of the effect of interstitial carbon on the anodic dissolution of martensite.
The base specimen was AISI 1045 carbon steel, and the chemical composition of this steel (mass%) was 0.44%C, 0.20%Si, 0.85%Mn, 0.008%P, 0.002%S, <0.01%Ni, <0.01%Cr, <0.01%Mo, <0.01%Cu, <0.001%Ti, <0.002%Nb, 0.035%Al, 0.003%N, and 0.002%O. The specimens were heat-treated at 1123 K for 10 h in air and then, quenched in water. Since the surface of the specimens was decarburized during this heat-treatment, the low carbon martensitic structure was formed in the surface region of the specimens, and high carbon martensitic structure remained in the core area. Potentiodynamic polarization of the low and high carbon martensitic specimens was conducted using boric-borate buffer solution with 1 mM NaCl at pH 8.0. In addition to the electrochemical measurement, the first-principles calculations based on density functional theory (DFT) were carried out. For the calculation, the carbon concentration was varied from 0.40 at.% to 5.88 at.%.
In the potentiodynamic polarization curves of the low and high carbon martensitic specimens in 1mM NaCl containing boric-borate buffer at pH 8.0, the region of active dissolution appeared on both specimens at about -0.5 V. The dissolution current density for high carbon martensitic specimen was lower than that of the low carbon martensitic one, suggesting that the interstitial carbon suppressed the active dissolution.
Next, the effect of interstitial carbon atoms on the electronic structure of the martensitic structure was analyzed. It was clarified that the electronic density of states (DOS) of iron atoms at and near the Fermi level decreased by increasing carbon concentration. This result indicates that the interstitial carbon atom makes weak atomic bonding with the nearest iron atom, and stabilizes the electronic structure of martensite. This change in the energy state of iron atom was, therefore, attributed to the high corrosion resistance of martensitic carbon steels.
References;

M. Kadowaki, I. Muto, Y. Sugawara, T. Doi, K. Kawano, and N. Hara, J. Electrochem. Soc., 164, C962 (2017).

M. Kadowaki, I. Muto, Y. Sugawara, T. Doi, K. Kawano, and N. Hara, J. Electrochem. Soc., 165, C711 (2018).
Manipulation of a Single Crystal Nanowire on an Atomic Level
Authors: Košiček Martin , Filipič Gregor , Zavašnik Janez , Cvelbar Uros 
Published: February 2020

In recent years, metal oxide nanostructures (MO) have been intensively studied due to a wide variety of applications on multiple fields, for example in optoelectronics, gas sensing, photovoltaics, field-effect transistors, UV lasers, field emission sources etc. [1]. However, for applications, other types of structures are also interesting such as sulfides and nitrides. Here the question that raises is can we manipulate nanomaterials like nanowires on an atomic level. Knowing the exact mechanism of sulfur-oxygen exchange in the metal oxide crystal lattice can be utilized for the synthesis of metal sulfides with specific morphologies. When compared to metal oxides, single-crystalline metal sulfide nanostructures of specific morphologies are usually harder to produce than MOs. Generally, metal sulfide nanostructures represent unconventional materials in areas such as batteries or photovoltaics with yet unexploited potential, where their efficiency is mainly limited by the purity of crystalline phases and structural defects [2]. A promising path for novel synthesis route is incorporation of the sulfur in the crystal structure of a metal oxide nanoparticle, while during this transition the morphology of the nanostructure does not change. In this way, it is possible to obtain single crystal metal sulfide nanostructures from metal oxide nanostructures in the single crystal to single crystal (SCSC) transformation. A promising method to achieve such transformation in a short period of time is a treatment of metal oxide nanostructures with the plasma of sulfur-containing gas.
In this research, we studied the mechanism of sulfur incorporation in the metal oxide crystal structure. The procedure was carried out by synthesis of ultra-thin metal oxide nanowires, which were then treated with sulfur-containing gases under increased temperature (in thermodynamic equilibrium conditions) and in the plasma of the same gases (under thermodynamically non-equilibrium conditions). Experiments were conducted at different temperatures and pressures to evaluate the influence of plasma on transformation process. Mechanisms involved in the interaction of sulfur-containing species with metal oxides were studied on isolated single ultra-thin metal oxide nanowire. Furthermore, changes in crystal structures and their effect on the material properties before and after sulfurization were studied.
[1] Umar A. & Hahn Y. B. (Eds.). (2010), Metal Oxide Nanostructures and their Applications. American Scientific Publishers, CA, USA
[2] Zavašnik, J., & Rečnik, A. (2013). Electron microscopy study of CVT grown Fe-sulphides. Journal of Crystal Growth, 367, 18-23.
Co-Electroless Deposition of Pt-M Bimetallic Alloyed Catalysts for Methanol Oxidation
Authors: Meekins Benjamin , Tate Gregory , Xiong Wen , Weidner John , Monnier John R. 
Published: February 2020

Direct methanol fuel cells exhibit great promise as portable sources of power. A primary issue, however, is that the platinum catalyst used is readily poisoned by CO that is formed during the methanol oxidation reaction. Further, reducing the amount of Pt used is crucial to reducing the cost of direct methanol fuel cells. A straightforward way to address both issues is to synthesize bimetallic catalysts with Pt and a secondary metal that provides the necessary –OH groups to remove CO from Pt.
Co-precipitation and co-impregnation methods have traditionally been used for the synthesis of metallic and bimetallic catalysts. These methods, however, afford little control over nanoparticle composition, size, and spacing. Electroless deposition solves these issues by allowing precise compositional, size, and, when paired with strong electrostatic adsorption, spacing control. The Monnier group has developed a continuous deposition method that produces composition-controlled bimetallic alloyed catalysts on a seeded support.1

Mehrabadi et al.
2 demonstrated previously that Ru deposited by electroless deposition onto a Pt/C support was superior to commercial PtRu catalysts for methanol oxidation. Bimetallic and trimetallic catalyst syntheses have also been demonstrated. In this work, we synthesize Pt-Co and Pt-Ni bimetallic catalysts with controlled compositions. We find that specific compositions (Pt3Ni and Pt2Co) exhibit significantly improved mass activity. This talk will discuss the synthesis and characterization of these bimetallic alloyed catalysts as well as the activity for methanol oxidation observed.

Tate, G., Kenvin, A., Diao, W., Monnier, J. R., “Preparation of Pt-containing bimetallic and trimetallic catalysts using continuous electroless deposition methods,” Catalysis Today, (2018)

Tavakoli Mehrabadi, B.A., Catalysis Today, https://doi.org/10.1016/j.cattod.2018.11.042
Hydrogen Evolution Reaction on Co-Mo Electrodeposits with Nanoscaled TiO2
Authors: Podlaha Elizabeth J. , Wang Cheng 
Published: February 2020

Co-Mo alloys are well known as excellent electrocatalysts for hydrogen generation.1-3 In this work, nanoscale TiO2 particles were embedded into Co-Mo alloys during galvanostatic electrodeposition from a citrate-boric acid electrolyte. Following deposition, the deposits were characterized for their HER performance. Enhancements of the exchange current density and of a lower overpotential with the composites compared to the alloy were observed, and interpreted with a Volmer-Tafel/Heyrovsky mechanism.
The HER kinetics depends on both the Mo and TiO2 composition. For example, in an alkaline electrolyte, the exchange current density exhibited a volcano-type behavior with the Mo composition in the deposits. At the maximum value of the exchange current density, the addition of TiO2 further increased its value nearly 3 times higher than the Co-Mo alloys, accounting for the difference in the electroactive surface area. Figure 1 shows polarization curves of deposits with nearly similar Mo:Co ratios with and without TiO2 in a 1 N NaOH electrolyte. The overpotential at -10 mA/cm2 decreased significantly when particles were present in the deposit by 37 mV, in this example, compared to the alloy in Figure 1. Other deposits having different Mo wt % compositions exhibited a variation in the overpotential reduction between 22-55 mV at similar exchange current densities. The Tafel slope absolute value of all deposits with TiO2 having similar Mo:Co ratios were in the range of 70-75 mV/dec. The Tafel slopes of the alloy, without TiO2, and having high Mo content, was comparable to the composite. When the alloy composition contained less Mo the Tafel slope absolute value increased. In acid, an experiment with a Co-Mo alloy verifies a further decrease of the overpotential, but corrosion of the metal and titania places limitations on the pH.

References

C. McCrory, S. Jung, I. M. Ferrer, S. M. Chatman, J. C. Peters, T. F. Jaramillo, J. Amer. Chem. Soc. 137, 4347 (2015).

P.R. Żabiński, H. Nemoto, S. Meguro, K. Asami, K. Hashimoto, J. Electrochem. Soc.
150,C717 (2003).

Y. Zhang, Q. Shao, S. Long, X. Huang, Nano Energy
45, 448 (2018).

Figure 1
Insight into Oxidation of Ultra-Fine Lead Powder By Electrodeposition
Authors: Yang Chang-jiang , Zhao Lv-xing , Gu Yu 
Published: February 2020

Pure lead powder has multiple application such as oil and gas exploration, X-ray shield, golf club manufacture, paints, lubricating grease and anti-friction products. Electrochemical deposition of lead powder can be obtained from both the acid electrolytes based on fluoroborate, acetate, fluorosilicate, nitrate, etc. and an alkaline solution. Morphological characteristics of lead powder with overpotential have been detailed in previous literatures. Nevertheless, oxidation of lead powder during electrodepositing process was out of view, which actually decreased the purity and quality of lead powders compared to atomized ones.
In this investigation, ultra-fine lead powders with a minimum median diameter of 4.5 μm were electrodeposited in solution consisting of 2 M CH3COONa, 2 mM Pb(CH3COO)2 and pH values adjusted by acetic acid. The degree of as-deposited lead powder was defined as the content of PbO in wt %, and was determined by complexometric titration with EDTA. The morphology of lead powders shown by SEM was a classical dendrite and branches, which resemble a tree. The oxidation of lead powder reached to about 16% when pH value of electrolyte was 1 and decreased abruptly to around 6 % at pH from 3 to 7. The oxidation of lead powder was stable at ~5.5 % with the cathodic current densities from 23 mA cm-2 to 36 mA cm-2 and increased to 9 % and 13% at current densities of 10 and 45 mA cm-2 respectively. The concentration of gelatin as an additive accelerated the oxidation of lead powder. When ultrasonic was applied, the oxidation degree of lead powder became 3-fold larger than that of the stirred one. More importantly, the average sizes of powder have a directly relationship with the degree of oxidation. The smaller median diameter is, the larger degree of oxidation is.
However, the XRD of the lead powder with about 16 % oxidation shows only metallic Pb with strongly preferred orientation in (111) plane, which indicated the amorphous PbO powders. The results of TEM confirmed the amorphous materials around lead particles, which suggested metallic Pb was partly transformed from PbO. Therefore, we suggested a mechanism of lead electrodeposition result in oxidation of lead as follows:

Deprotonation: [Pb(H2O)]2+ → [PbOH]+ + H+

Electrochemical reduction:

Lead reduction—
Directly：[PbOH]+ + H+ + 2e- → Pb + H2O
Indirectly: [PbOH]+ → PbO + H+

PbO + 2H+ + 2e- → Pb + H2O
Hydrogen evolution—
2[PbOH]+ + 2e- → 2PbO + H2

2H+ + 2e- → H2

The reason of forming [PbOH]+ complex is due to the stability constant, lgβ=13.3, which is about 10 order of magnitude large than that of acetate complexes, lgβ=3.60.

Figure 1
Investigation of Metal Ion Diffusion and Reduction Potential in Several Ionic Liquids
Authors: Horwood Corie , Pham Tuan Anh , Maiti Amitesh , Peters Vanessa N. , Stadermann Michael 
Published: February 2020

Electrodeposition is proving to be a promising technique for forming metal capsules and other components required for Inertial Confinement Fusion (ICF) experiments performed at the National Ignition Facility. While we have recently demonstrated that non-porous, defect free parts can be electrodeposited from a variety of water-based solutions,1,2 many of the preferred metals for the ICF program (beryllium, uranium, etc.) cannot be deposited because electrolysis of water occurs at the potential required to reduce such metals.
To circumvent this, we are currently investigating Ionic Liquids (ILs) as solvents for metal electrodeposition, as the wide (~ 6 V) electrochemical window of ILs is expected to allow electrodeposition of Be, U, and many other metals.3 We are investigating the key parameters of metal ion diffusion and reduction potential for two model metals, silver and copper, in several different ionic liquids. We use electrochemical measurements along with first principles density functional theory (DFT) simulations to understand how ionic liquids affect diffusion and reduction potential, and this understanding will be applied to selecting appropriate ILs for deposition of metals such as Be and U.
Funding was provided by Lawrence Livermore National Laboratory Directed Research and Development (LDRD) Grant 17-ERD-047. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. IM release LLNL-ABS-771850.
(1) Horwood, C.; Stadermann, M.; Bunn, T. L. Fusion Sci. Technol.
2018, 73 (3).
(2) Bunn, T.; Horwood, C.; Stadermann, M. Cathode System for Electrodeposition of Metals on Microspheres. US Patent 16336-000075-US-PS1, 2018.
(3) Electrodeposition from ionic liquids, 2nd ed.; Endres, F., Abbott, A., MacFarlane, D., Eds.; Wiley-VCH: Weinheim, Germany, 2017.
Investigation on Parameters Influencing the Electrodeposition of Niobium-Based Layers
Authors: Endrikat Anna , Ispas Adriana , Bund Andreas 
Published: February 2020

The refractory metal niobium is used in technical applications because of its excellent corrosion and wear properties and as alloying element in steel or in superalloys for high temperature applications. In order to open new fields of application with maximum material efficiency, electrochemically produced niobium protective layers are suitable because they can increase the life-time of critical components.
In principle, the electrochemical production of niobium-based layers is possible. However, due the very cathodic standard potential of refractory metals they cannot be electrodeposited from aqueous electrolytes. The ionic liquids (ILs) allows electrochemical deposition of niobium due to its high electrochemical stability (5 – 6 V electrochemical window) and low melting point <100°C.
Usually metal halides (e.g. NbCl5) are used as precursors for electrochemical niobium deposition. The transfer of five electrons in several individual steps results in a complex reduction mechanism that can adversely affect the film formation, e.g. by formation of stable intermediates.
Applying higher temperatures, additives (e.g. [BMP]Cl, LiCl) or pulsed potentials, the electrode/electrolyte interface changes and the deposition of niobium can be specifically influenced. Another possibility for optimizing the niobium-based layers is based on pre- and post-treatment (e.g. anodic etching).
This contribution will discuss the influence of temperature, additives as well as the use of special pulse parameters on electrochemical niobium deposition. The aim is to find suitable deposition, pre- and post-treatment conditions and thus to optimize the resulting niobium-based layers. By means of various techniques such as cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical quartz microbalance (EQCM), as well as scanning electron microscopy, a better understanding of the reduction mechanism of niobium halides in ILs in the presence of selected additives shall be obtained.
Noble Metals Alloys Deposition from Non-Aqueous Solvents
Authors: Manolova Mila , Böck Reinhard 
Published: February 2020

Binary alloys of Pd and Pt were successfully deposited from 1-butyl-3-methyl imidazolium tetrafluoroborate (BMIM-BF4-Cl) ionic liquid and from a deep eutectic solvent (DES) based on a mixture of choline chloride and urea (ChCl-UA) at ambient atmosphere conditions. Ag, Ni and Sn were used as alloy components. Cyclic voltammetry experiments on glassy carbon electrode showed the reduction and dissolution of the alloys in the investigated solvents. Pulse plating and potentiostatic deposition techniques were used to deposit PdAg, PdNi, PdSn and PdPt alloys on cylindrical Cu substrate. The composition of the layers could be varied either by the concentration of the metals in the electrolyte solution or by changing the deposition mode (pulsed current or potentiostatic deposition).
In order to determine the surface morphology and the thickness of the electrodeposited noble metal alloy films, a high resolution scanning electron microscope (SEM/EDX) and an energy dispersive X-ray fluorescence spectrometer (XRF) were used. The surface morphology of the layers was remarkable affected by the composition of the alloys. Scanning electron micrographs of the different electrodeposits showed that Pd alloys deposited by pulse current were generally nodular and relatively compact, whereas the films deposited by potentiostatic deposition were less dense and covered with dendrite-like and sharp-edged crystallites.
The addition of a second metal (e.g. Ag+ or Sn2+) to a basic Pd or Pt electrolytes enhanced the overall metal deposition rate in comparison to solutions without alloying components and caused a remarkable increase of the layer thickness of the alloys.
XRD measurements confirm that it was possible to deposit different binary metal alloys from both non-aqueous electrolytes by applying different deposition techniques.
First adhesion tests and measurements of the microhardness of Pd-Ag deposits showed good properties of the produced alloy films. Also the hydrogen embrittlement of selected samples was proved by a hydrogen analyzer. These results confirmed that the quantity of hydrogen was negligible in the Pd alloy films produced from ionic liquids in comparison to films obtained from conventional aqueous solutions.
(Invited) Thoughts on the Viscous Sublayer
Authors: Newman John 
Published: February 2020

Years ago people postulated that there is a laminar sublayer near a solid wall in turbulent flow. Murphree (1932) and Levich (1942, 1944) postulated that the turbulence eddies decay only gradually as the solid wall is approached. There are two schools of thought: one says that the eddy diffusivity is proportional to y
3 near the wall; the other says y
4. Which is right?
Perhaps there is some truth in both views. It may be that y
4 prevails near the outer limit of the viscous sublayer, adjacent to the outer turbulent flow, but that y3 prevails very close to the wall.
It has been thought that this was important only for mass transfer in turbulent flow at high Schmidt numbers, that is, for diffusion coefficients much smaller than the kinematic viscosity. However, it is shown that Nikuradse’s data (1932) for pressure drops (or friction factors) in turbulent pipe flow do not agree with his very careful measurements of profiles of the eddy viscosity. In other words, the viscous sublayer cannot be ignored even in fluid flow.
The profile of predicted eddy diffusivity of Wasan, Tien, and Wilke (1963) show regions of y
3 dependence very close to the wall and y dependence in the outer turbulent flow with perhaps a y
4 dependence in the intermediate region.
On this diagram, one can identify the thickness of the diffusion layer as a function of the Schmidt number. As is well known, the diffusion layer gets very thin at high Schmidt numbers. Using this profile, one can show that the y
4 dependence will not show up clearly in mass-transfer data at any Schmidt number. Any region of y
4 dependence of the eddy diffusivity is outside the diffusion layer where the concentration does not change (at high Schmidt numbers).
These thoughts inspire a method of calculating the profiles of eddy diffusivity and eddy viscosity from consideration of fluctuations themselves. Hopefully this can be a subject of future work.
(Invited) Synthesis, Characterization, and Investigation of Non-Arrhenius Behavior in Anti-Perovskite Ion Conductors
Authors: Wang Fei , Tsai Ping-chun , Li Yiliang , Eiler Stephanie L. , Son Seoung-Bum , Chiang Yet-Ming 
Published: February 2020

Amongst known families of solid electrolytes of potential interest for solid-state batteries, the anti-perovskites (A3BX) are of interest for the high ionic conductivities observed in certain compositions (see Figure), and, like perovskites, the compositional flexibility provided by the possibility for ion substitution onto multiple lattice sites. For example, variations in the relative size of ions A, B and X result in changes in the Goldschmidt tolerance factor, or extent of disorder, that are accompanied by changes in the distribution of lithium migration energies. [1]
In surveying transport in this family of ion conductors, we observed a trend wherein numerous compositions show upwards curvature on an Arrhenius plot (see Figure), indicating a non-constant activation energy. This is unusual as most solids exhibiting non-Arrhenius behavior exhibit a negative deviation. We have synthesized a wide range of Li and Na anti-perovskites, and have confirmed non-Arrhenius conductivity with a positive deviation in compositions such as Na3OBr0.6I0.4. This talk will discuss compositional trends related to this behavior, and our attempts to understand the structural origin(s) of this behavior through temperature-dependent X-ray and neutron scattering, calorimetry, and other methods. Implications for the design of solid electrolytes for solid state batteries will be discussed.

This work was supported as part of the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences.

[1] Kwangnam Kim and Donald J. Siegel. "Correlating lattice distortions, ion migration barriers, and stability in solid electrolytes." Journal of Materials Chemistry A 7, no. 7 (2019): 3216-3227.

Figure 1