bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Welding of Nickel Nanowires By Ions Beam Irradiation: From Small to Large Scale
Authors: Honey Shehla , Ahmad Ishaq , Naseem Shahzad , Malik Maaza , John Kennedy 
Published: February 2020

In order to replace conventional transparent conducting electrodes, metal nanowires (MNWs) networks have long been act as promising contenders due to their high mechanical flexibility. However, nanowire-nanowire contact resistance is main technical obstruction in terms of improvement in their performance. To reduce nanowire-nanowire contact resistance, welding of nanowires (NWs) is essential.
In this work, MeV proton and argon ions beam irradiation induced nanoscale welding technique to fabricate X-, Y-, II- and T-shaped molecular junctions between nickel nanowires (Ni-NWs) is presented. Ni-NWs are irradiated by 2.75 MeV proton ions and 3.5 MeV argon ions at doses 1x1016ions/cm2 and 5x1015 respectively while temperature is kept constant. Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and x-ray diffraction (XRD) results reveal that Ni-NWs are welded without losing stability in crystal structures of NWs. Afterward, a two-dimensional large scale random network of Ni-NWs is fabricated by 3 MeV proton ions beam irradiation induced nanoscale welding of Ni-NWs at crossing positions. Proton ion beam induced large scale network fabrication is confirmed by TEM and SEM techniques. Moreover, these networks are characterized optically using UV-VIS spectroscopy. It is observed that at a beam fluence of 5x1015 ions/cm2, perfect molecular junctions between Ni-NWs in X-, II-, and V-shapes are achieved and a large scale welded network of Ni-NWs is obtained without distorting the morphology of NWs. Moreover, structure of Ni-NWs remains stable under 3MeV proton ions beam irradiation and networks are found to be optically transparent. The results exhibit that fabrication of Ni-NWs network precede through three steps:

i- High energy ions beam irradiation induced heat spikes lead to locally heat and fuse Ni-NWs,

ii- Formation of molecular junctions on small scale,

iii- Formation of large scale network
Ions beam irradiation induced welding of Ni-NWs can improve performance of NWs networks by reducing contact resistance between NWs for application as transparent conducting electrodes. These high quality welded MNWs networks may potentially be applied as transparent conducting electrodes in optoelectronic devices.
Nickel Metal Alloy’s As PGM-Free Catalysts for Hydrogen Oxidation Reaction in Anion Exchange Membrane Fuel Cells
Authors: Roy Aaron Joseph , Atanassov Plamen , Artyushkova Kateryna , Serov Alexey , Zulevi Barr , Rezaei Talarposhti Morteza 
Published: February 2020

Anion exchange membrane fuel cells (AEMFCs) offer considerable advantages over proton exchange membrane fuel cells (PEMFCs) in that the kinetics for oxygen reduction reaction (ORR) are greatly improved in alkaline media [1]. The improved kinetics of ORR in alkaline media thus allows for the use of PGM-Free catalysts in AEMFCs. Though there have been many efforts to develop PGM-Free cathode catalysts for AEMFCs, PGM-Free anode catalysts, with catalytic activity for HOR comparable to Pt, are still in the early stages of development [2]. The slow development of these AEMFC anode catalysts is largely due to the lack of compatible ionomers for anion exchange. However, recent development of anion exchange ionomers show great improvements over PEMFC ionomers, such as NAFION, in AEMFCs [3].
Carbon supported nickel has been shown to have high activity for HOR in AEMFCs, however the susceptibility of Ni to electrochemical oxidation, as well as the less than optimal hydrogen binding energy to the Ni active site, suggest there is further room for optimization of the Ni/C system [1]. Here, we have proposed to address these issues through alloying Ni with transition metals to tune the electronic environment of Ni, as well as to improve the corrosion resistance of Ni in alkaline media.

For this project, catalysts are prepared by an incipient wetness method using the metal nitrates as catalyst precursors and KetjenblackÒ, DENKA BLACKÒ, graphene oxide (GO) and reduced graphene oxide (rGO) as support materials. GO and rGO have been prepared from Hummers’ method. In some cases, a sacrificial support method is also used to control the primary particle size of the NiM materials.
Figure 1 shows the open circuit and close circuit polarization curves for NiMo/C with peak power density observed for HOR of ~ 120 mW/cm2, which is an encouraging result though not competitive with Pt or Pd. Therefore, our aim is to explore the role of the alloying metal (M = Mo, W, Cr, Co, Cu) as well as to investigate the role of the carbon support (ex: GO, rGO, N-doped rGO) on the kinetics of HOR in alkaline media on these NiM/C catalysts.
References:
[1] Zhuang, Z.; Giles, S. A.; Zheng, J.; Jenness, G. R.; Caratzoulas, S.; Vlachos, D. G.; Yan, Y. Nature Communications 2016, 7, 10141.
[2] Serov, A.; Kwak, C. Applied Catalysis B: Environmental 2009, 90 (3-4), 313–320.
[3] Kreuer, K.-D. Fuel cells: selected entries from the Encyclopedia of Sustainability Science and Technology; Springer: New York, 2013.

Figure 1
Structural and Chemical Evolution of Li-Rich Li2IrO3 during Electrochemical Cycling
Authors: Li Liang , Castro Fernando , Park Joong Sun , Lee Eungje , Freeland John W , Yao Zhenpeng , Fister Timothy T , Vinson John , Shirley Eric , Wolverton Christopher , Dravid Vinayak , Thackeray Michael M. , Chan Maria K. Y. 
Published: February 2020

In the pursuit of novel cathode materials with high Li capacities, the Li-rich oxides with Li/TM (transition metal) ratio larger than 1 have recently gained increased interest. For instance, the active role of oxygen ions in the charge compensation has been reported in layered rocksalt Li2IrO3,1 which serve as a model system to understand the structural response of Li-rich cathodes to Li extraction, as well the role of oxygen in compensating Li+ loss.
In this study, we employed various experimental techniques as well as first-principles density functional theory (DFT) to investigate the structural and electronic evolution of Li2IrO3 upon electrochemical cycling. It is found that Li2IrO3 undergoes phase transition and slight capacity fading at each cycle. All the thermodynamically stable phases of Li2-xIrO3 (0≤x<2) are identified through a complete structural screening based on electrostatic energy and DFT calculations. Electron Energy Loss Spectroscopy (EELS) and X-ray Absorption Near Edge Spectroscopy (XANES) are adopted to probe the changes in the oxygen electronic structure at various (de)lithiation stages, and corresponding O K-edge spectra are simulated based on first-principles calculations. The cationic/anionic charge compensation mechanism of Li2IrO3 upon delithiation is discussed based on the spectroscopic observations.
1. E. McCalla et al., Science, 350, 1516–1521 (2015)
Molybdenum Substituted Vanadyl Phosphate ε-VOPO4 for Lithium-Ion Batteries
Authors: Siu Carrie , Lee Krystal , Omenya Fredrick , Chernova Natasha , Whittingham M. Stanley , Lin Yuh-Chieh , Ong Shyue Ping 
Published: February 2020

Maintaining the structural reversibility of multiple electron transfer cathodes is a challenge one has to address in order to increase the energy density of current lithium-ion batteries. ε-VOPO4 is a promising cathode material with two redox transitions of V3+/V4+ and V4+/V5+ at about 2.5 and 4 V, respectively. However, the reversibility and cycling stability is compromised with more than one lithium cycling. The goal of this work is to investigate if the substitution of molybdenum can enhance the electrochemical performance of ε-VOPO4. We have focused on molybdenum because it is predicted by the first-principle calculations to display multiple redox potentials in useful voltage window and to form relatively stable substituted ε-VOPO4 phases. We have refined the synthesis method, where by changing a solvent we can control morphology and obtain either loose uniform 100 nm particles, or make those particles form secondary micron-sized spheres. Combing the analysis of X-ray diffraction, and inductively coupled plasma mass spectrometry, we have determined the limits of molybdenum substitution in the structure. The effects of the substitution and morphology on the electrochemical performance will be discussed. This research is supported as part of the NorthEast Center for Chemical Energy Storage (NECCES), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0012583. CS gratefully acknowledges the financial support from Graduate Assistance in Areas of National Need (GAANN) Fellowship and Binghamton University Provost's Doctoral Summer Fellowship.
Novel Nanomaterials and Systems for Solar Fuel and Chemical Production
Authors: Mubeen Syed 
Published: February 2020

Becoming more energy sustainable is a major current societal goal, which, of necessity, involves greater use of sunlight as a primary source of energy. However, if solar energy is ever to displace fossil fuels as our main energy source, it could only do so if we solve the energy storage problem. The first portion of the talk will introduce our research efforts to develop novel fault tolerant semiconductor nanostructured architectures for solar fuel production. Focus, would be on single nanowire photoelectrochemistry to understand carrier transport pathways across multiple interfaces. The second part of the talk will focus on exploring hot electrons from plasmonically active metals to drive important fuel and chemical producing reactions such as water splitting and CO2 reduction reaction.
Visible-Light Active Thin-Film WO3 Photocatalyst Crystallized By Post-Annealing in Air
Authors: Oka Nobuto , Takashima Junya , Murata Akiyo , Jia Junjun , Shigesato Yuzo 
Published: February 2020

Photocatalysts with visible light activity have been widely studied in recent years. We have reported on WO3 films as the high-performance visible-light active photocatalyst [1,2]. These films were deposited by dc magnetron sputtering on heated fused silica substrates at 800 oC. It must be preferable for the industrial application that the substrate temperature during the deposition should be lower for the window coatings for automobiles and architectures. In this study, the effect of post-annealing in air and total gas pressure during the deposition were studied. In addition, the loading effects of Pt nanoparticles on the WO3 film surface were also studied for the improvement of the photocatalytic activity.
The WO3 thin films were deposited on unheated fused silica glass substrates by dc magnetron reactive sputtering using a W metal target, and with Ar and O2 as the sputtering and reactive gases, respectively. Post-annealing temperature was varied from 300 to 800 oC for the films sputter deposited at total gas pressure of 5.0 Pa. Furthermore, total gas pressure during the deposition was varied from 1.0 to 9.0 Pa. After the post-annealing at 400 or 600 oC, Pt nanoparticles were deposited on the WO3 film surface also by sputtering for 0, 7 or 40 sec. The surface coverage of Pt on the WO3 films were estimated by X-ray photoelectron spectroscopy. The Photocatalytic decomposition of acetaldehyde (CH3CHO) on the Pt/WO3 films was evaluated by the decrease in the concentration in the quartz cell. The visible light source was a Xe lamp with a 410-500 nm band pass filter (1.0 mW/cm2 at the film surface).
Figure shows the photocatalytic decomposition for the WO3 films loaded by the Pt nanoparticles under visible light irradiation. It was found that the potocatalytic activities of the films crystallized by post-annealing（400 oC）was superior to the films deposited on the heating substrate at 800 oC, which was enhanced by the Pt loadings.
[1] M. Kikuchi, Y. Shigesato, et al., Abstract of the 21st IUPAC SYMPOSIUM (2006) 496.
[2] M. Imai, N. Oka, Y. Shigesato, et al., J. Vac. Sci. Technol. A 30, 031503-1-031503-5 (2012).
[3] N. Oka, Y. Shigesato, et al., APL Materials 3, 104407-1-104407-6 (2015).
[4] N. Oka, Y. Shigesato, et al., Jpn. J. Appl. Phys. 51, 055501-1-055501-5 (2012).

Figure 1
Effects of Ionic Liquids on Biofilm Formation in a Loop-Type Laboratory Biofilm Reactor
Authors: Kanematsu Hideyuki , Saito Tatsuki , Hirai Nobumitsu , Kogo Takeshi , Ogawa Akiko , Tsunashima Katsuhiko 
Published: February 2020

Biofouling and biofilm formation on inside walls of pipes where various liquids flow have caused varoius netagive industrial problems so far, since it would lead to corrosion, slimes and scales to deteriorate the functions such as heat exhcnage capability and materials qualities/characteristics themselves. As the countermeasure, various biocides and chemical cleaners have been used to control liquid qualities and to prevent those negative industrial problems. Various acids, alkaline agents, surfactants etc. have been used conventionally so far. At this point, hypoochlorous acid and some organic agents seem to be excellent chemical cleaners. However, the former might induce corrosoin on the substrate walls. On the other hand, the latter might evaoprate during the use, evne though any of them might show higher performances. In this experiment, we focused on some ionic liquids. They might be able to overdome those defencts mentioned above. When we come to think about the applicability of ionic liquids to practical industrial purposes, the price and the environmental friendliness may be serious problems in the futuure. In those cases, it will be key points how we could minimize the amount of use for the purpose. Therefore, we tried in this experiment to confirm how very small amounts of some ionic liquids could control biofilm formation. To produce biofilms articially with good reproducibility, we used a loop-type laboratory biofilm reactor which we designed and produced in our laboratory. Two kinds of ionic liquids were used for the experiments. 1-Butyl-3-methylimidazolium Tetrafluoroborate(BMImBF4) and Tributhylocthylphosphonium chloride(P4448Cl). Small amount of them were added into LBR filled with tap water. The liquids including ionic liquids were circulated by a pump and biofilms formed on specimens placed with a stick-type jig, being parallel to the flow direction. After a couple of days passed, the specimens were talken out from the system and the material surfaces were observed. Some types of liquids without ionic liquids were used as control and all of these specimens after exposures in the LBR were analyzed by optical micrscopes, staining by crystal violets and Raman spectroscopy and discussed. The effect of ionic liquds were obviously recognized during the initial stage of biofilm formations. However, ionic liquids also had the difficulty to disolve the solidified biofilms contained lots of calcium carbonate produced at the second half of biofilm formation process.
Theoretical Investigation of Vanadium Crossover Phenomena through Different Types of Membrane in Vanadium Redox Flow Battery
Authors: Jeong Daein , Jung Seunghun 
Published: February 2020

Redox flow batteries (RFBs) as enery storage system are getting much public attention because their power and capacity can be configured independently with relatively low capital investment compared to other types of batteries. All vanadium redox flow battery (VRFB) has an additional advantage of low maintenance cost. In detail, becasue positve and negative electrode of a VRFB share the same active material (vanadium), contaminated electrolyte due to vanadium crossover through membrane can be recycled by rebalancing process. Electrolyte contamination in a VRFB is mainly caused by the amount of vanadium and water crossover through the membrane, which causes capacity decay and power loss accompanied by additional maintenance cost during VRFB operation.
The vanadium crossover is controlled by diffusion, migration, and convection across the membrane. It was reported that the following side reactions occur when vanadium ions move to the counter electrode side (1):
It is also known that the water transfer through the membrane is controlled by three mechanisms as follows (2):
1) Water molecules are transferred along with a vanadium ion that moves to the counter electrode
2) Water molecules are transferred along with a proton to satisfy electro-neutrality
3) Water molecules are transferred by osmosis phenomenon due to vanadium concentration difference between two electrolytes
The above vanadium and water transfer through membrane strongly denpends on the physico-chemical properties of the membrane. In this study, we aim to elucidate crossover phenomenon and its consequence in a VRFB by taking computational apporach with a physics-based multi-dimensional VRFB model that has capability of simulating complex species transfer mechanisms. Further, we analyze the cause and effect of each crossover mechanism according to the different types of membranes such as anion exchange membrane, cation exchange membrane, and micro-porous separator. We conclude our study by suggesting electrolyte rebalancing strategies for each type of membrane.

References

[1] K. W. Knehr, Ertan Agar, C. R. Dennison, A. R. Kalidindi, and E. C. Kumbur, J. Electrochemical Society 159(2012) A1446-A1459
[2] Chenxi Sun, Jian Chen, Huamin Zhang, Xi Han, Qingtao Luo, J. Power souces 195 (2010) 890-897

Figure 1
MXenes As Candidate Cathodes for Non-Aqueous Lithium-Oxygen Batteries
Authors: Lee Andrew , Krishnamurthy Dilip , Viswanathan Venkatasubramanian 
Published: February 2020

Nonaqueous lithium-oxygen (Li-O2) batteries have emerged as possible high energy density alternatives to Li-ion batteries that could address the limited driving range issues faced by electric vehicles. This battery chemistry allows for high energy densities and an exceptionally high theoretical efficiency. Carbon, the current cathode catalyst, exhibits low stability against oxidation and reacts with the products formed during the discharging phase of the battery. In addition, due to other undesired side-reactions while charging the battery, all the reactants are not recovered leading to a poor rechargeability of a few cycles. A good cathode that can mitigate these issues requires careful screening and can help improve cycle life, increase capacity and help mitigate electrolyte decomposition. In this work, we focus on identifying possible cathodes from a family of intriguing two-dimensional (2D) materials known as MXenes, for lithium-oxygen batteries. MXenes have a general formula of Mn+1Xn, where M is an early transition metal and X is nitrogen or carbon, and being 2D layered materials, they have a large surface area [1]. MXenes are possible cathode candidates for lithium-air batteries owing to two considerations: (i) high electronic conductivity and (ii) high stability. We explore MXene carbides and nitrides of various transition metals as potential cathodes with low nucleation overpotentials.
We use density functional theory (DFT) calculations to investigate the stability and activity of various terminated and non-terminated nitride and carbide MXenes of transition metals. We begin by exploring the MXenes of titanium and scandium such as Ti4N3, Ti4C3, Sc4N3, Sc4C3and their variants with the F, O and OH terminated groups. We observe that the nitrides are more stable than the carbides, and this trend holds also for the terminated compounds. Between the scandium and titanium MXenes, the titanium carbides are more stable than their scandium carbide equivalents; however, this observed trend is reversed for the nitride MXenes, with the scandium nitrides being more stable than titanium nitrides.
The nucleation overpotential for Li-O2 batteries is determined by the adsorption free energy of the intermediate LiO2 [3]. We identify active MXene catalysts by computing the adsorption free energy through DFT calculations and we find that the non-terminated carbides and nitrides are stronger binding than the optimal binding strength. The transition metal and the termination group in the MXene are two tuning variables to weaken the binding in order achieve optimal binding strength. We will report on the activity and coverage effects of various transition metal carbide and nitride MXenes to identify promising cathodes for the Li-O2batteries.

References

[1] Naguib, M. et.al. Adv. Mater., 2014, 26, 992-1005.
[2] Urbankowski, P. et.al. Nanoscale, 2016, 8, 11385-11391
[3] Krishnamurthy, D. ACS Energy Lett. 2016, 1, 162-168

Figure 1
Electrochemical Synthesis of Well-Ordered Macroporous Structures of Nickel – Ruthenium Alloys with Low Overpotential on Hydrogen Evolution Reaction
Authors: Kutyla Dawid , Kolczyk Karolina , Kowalik Remigiusz , Zabinski Piotr 
Published: February 2020

This work presents the results concerning electrochemical deposition of Ni-Ru alloys from aqueous acidic solutions. The Ni-Ru coatings were obtained by the potentiostatic electrodeposition on copper porous substrates and polystyrene matrix. The influence of applied potential and concentration of electroactive species on the composition and the quality of obtained coatings was determined. The elemental composition was determined with the XRF method. X-Ray analysis has been use to determine phase composition of obtained alloys. The surface morphology was investigated with the use of scanning electron microscopy. Electrochemical measurement as a linear and cyclic voltammetry was used to perform comparative examination of catalytic properties of the obtained 3-D structures in aqueous NaOH solutions.
Acknowledgment
The authors would like to thank Polish National Science Centre for the financial support provided by the grants: No UMO-2016/21/N/ST8/00222.