bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrodeposited Ni-Fe-Co Alloys for Magnetoelastic Resonators
Authors: Pillars Jamin R. , Langlois Eric D. , Monson Todd C. , Gucik Mary Louise , Pearce Charles Joseph , Delaney Robert , Maadi Ayham 
Published: December 2020

Magnetoelastic materials such as CoFe and NiFeCo alloys display Joule magnetostriction. This property of ferromagnetic materials is usually minimized as a loss mechanism in applications such as inductor or transformer cores. Though, for use as a resonating material in a sensor application, this material provides a battery-less system where an external device can apply a magnetic field and receive a magnetic “signal” in return based upon the resonant frequency, geometry, and mass. As-deposited CoFe and NiFeCo films have no measurable resonant frequency when analyzed with a vector network analyzer and biasing Helmholtz coils. To control magnetic properties of the electrodeposited alloys, the stoichiometry was controlled and additional elements such as boron, niobium, silicon, germanium, and holmium were added to the chemistry. The electrical resistivity was increased and the magnetic properties such as permeability, coercivity, and magnetic saturation were controlled and comparable to commercial, extruded ribbon materials such as Metglas. Annealing studies in a magnetic field, applied both parallel and perpendicular to the easy axis of the NiFeCoBNbSi and other alloy films, were used to adjust the anisotropy and the permeability of the material.
Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA-0003525, SAND2020-5481 A . The views expressed in the article do not necessarily represent the views of the U.S. Department of Energy or the United States Government.
Rare Earth Doped Nanoparticles for Theranostics
Authors: Vetrone Fiorenzo 
Published: December 2020

In the biomedical field, research has recently focused on nanoparticle-based “theranostic” agents for the treatment of diverse diseases, including cancer. This new paradigm in personalized medicine intends to exploit nanoplatforms that carry both therapeutic and diagnostic (theranostic) modalities. Compared with delivering drugs or imaging agents separately, theranostic agents can simultaneously deliver them to specific sites, enabling detection and treatment of disease in a single procedure. Many theranostic nanoplatforms are triggered by light, however, the vast majority of these are limited in that the ultraviolet or visible excitation light used has minimal applicability in biological applications. Rare earth doped nanoparticles, on the other can be excited with biologically friendly near-infrared light (in the biological windows) and can emit in the ultraviolet, visible or near-infrared regions through a multiphoton upconversion process while simultaneously emitting in the near-infrared region (also in the 3 biological windows) through a Stokes or downshifted process. Hence, the upconversion luminescence can be used to trigger the therapeutic application (drug delivery, photodynamic therapy, etc.) while the near-infrared luminescence can be used for the diagnostic modality (bioimaging, nanothermometry/temperature sensing, etc).
In this presentation, we will introduce rare earth doped nanoparticles and demonstrate their usefulness in theranostics. In particular, we will show that complex nanoparticle architectures can endow further functionality to these nanoparticles and discuss how they can be used for temperature sensing (nanothermometry) in biological systems.
Electrochemical Amplification Methods in Observation of Single Nanoparticle Collisions
Authors: Kwon Seong Jung 
Published: December 2020

We describe the electrochemical detection of single nanoparticle (NP) collision at a less catalytic electrode. We could observe the various single NP collision through the enhanced current by electrocatalytic redox recycling. The current responses were caused by random individual events as a function of time rather than the usual continuous current caused by an ensemble of a large number of events. The overall current transient such as spike-like or staircase, changed depending on the reaction mechanism of collided NP. The height and frequency of the peak current are proportional to the applied potential and the particle concentration.
Single iridium oxide (IrOx) NP collision at a less catalytic electrode surface such as the NaBH4-treated Pt or the bare Au ultramicroelectrode (UME) was investigated. The overall current transient consists of repeated current spikes, superimposed on a current decay to reach a steady-state value.
Collisions of Ag NPs with a more electrocatalytic Au or Pt surface have been observed. Depending on the applied potential to the UME, the current response of Ag NPs collision onto the UME resulted in various shape changes. A staircase decrease, a blip decrease, and a blip increase of the hydrazine oxidation current were obtained at an applied potential of 0.33 V, 0.80 V, and 1.3 V, respectively.
The current response of ascorbic acid stabilized Cu single NP collision on Au UME surface was observed. Here, the glucose oxidation electrocatalyzed by oxidized Cu NP was used as the indicating reaction. In this system, the NP collision signals were obtained simultaneously by both direct particle electrolysis and electrocatalytic amplification.
Atomically-Dispersed Functional Materials: From Single-Atom Electrocatalysts to Single-Atom Nanozymes
Authors: Du Dan (Annie) , Lin Yuehe 
Published: December 2020

Nanomaterials with enzyme‐like activities, or nanozymes, have attracted lots of attention recently due to their advantages such as low cost, superior activity, and high stability. The complex structure and composition of nanozymes has led to extensive investigation of their catalytic sites at an atomic scale, and to an in‐depth understanding of the biocatalysis mechanisms.
Single-atom catalysts (SACs) offer the unique feature of maximum atomic utilization, providing a potential pathway to improve the catalytic activity of nanozymes. Recently, we have demonstrated a Fe-N-C single-atom nanozyme (SAN) that exhibits high peroxidase-like activity. The SAN consists of atomically dispersed Fe─Nx moieties hosted by metal–organic frameworks (MOF) derived porous carbon. Due to high single-atom active Fe dispersion and the large surface area of the porous support, the SAN provided a high specific activity which was almost at the same level as natural horseradish peroxidase (HRP). Besides, the Fe-N-C based SAN presented much better storage stability and robustness against harsh environments compared with natural enzymes. The biosensing applications of the SAN and their major challenges will be discussed.

References:

L. Jiao, H. Yan, Y. Wu, W. Gu, C. Zhu, D. Du, Y. Lin. When Nanozymes Meet Single-Atom Catalysis. Angew. Chem. Int. Ed. 2019, doi.org/10.1002/ange.201905645

C. Zhu, S. Fu, Q. Shi, D. Du, Y. Lin. Single-Atom Electrocatalysts. Angew. Chem. Int. Ed. 2017, 56, 13944-13960.

N. Cheng, J. Li, D. Liu, Y. Lin, D. Du. Single-Atom Nanozyme Based on Nanoengineered Fe-N-C Catalyst with Superior Peroxidase-Like Activity for Ultrasensitive Bioassays. Small, 2019, 1901485.

X. Niu, Q. Shi, W. Zhu, D. Liu, H. Tian, S. Fu, N. Cheng, S. Li, J. N Smith, D. Du, Y. Lin. Unprecedented peroxidase-mimicking activity of single-atom nanozyme with atomically dispersed Fe-Nx moieties hosted by MOF derived porous carbon. Biosensors & Bioelectronics, 2019, 142, 111495.

Y Wu, L Jiao, X Luo, W Xu, X Wei, H Wang, H Yan, W Gu, BZ Xu, D Du, Y. Lin, C. Zhu. Oxidase‐Like Fe‐N‐C Single‐Atom Nanozymes for the Detection of Acetylcholinesterase Activity. Small, 2019, 15, 1903108

L Jiao, W Xu, H Yan, Y Wu, C Liu, D Du, Y Lin, C Zhu. Fe-NC Single-Atom Nanozyme for the Intracellular Hydrogen Peroxide Detection. Anal. Chem., 2019, 91, 11994-11999
(Invited) Near Infrared Optical Probes for Imaging Neuromodulators with High Spatiotemporal Resolution
Authors: Beyene Abraham 
Published: December 2020

Dopamine neurotransmission plays critical roles in brain function in both health and disease and aberrations in dopamine neurotransmission are implicated in several psychiatric and neurological disorders, including schizophrenia, depression, anxiety, and Parkinson’s disease. Until recently, measuring the dynamics of dopamine and other neurotransmitters of this class could not be achieved at spatiotemporal resolutions necessary to understand how dopamine regulates the plasticity and function of neurons and neural circuits, and how dysfunctions in this regulation lead to disease. Probes that satisfy critical attributes in spatial and temporal resolution, and chemical selectivity are needed to facilitate investigations of brain neurochemistry.
To address this need, we developed an ultrasensitive near-infrared “turn-on” nanosensor (nIRCat) for the catecholamines dopamine and norepinephrine and implemented nIRCat to study endogenous dopamine dynamics in brain tissue. nIRCats are synthesized from photostable and near infrared emissive functionalized single wall carbon nanotubes (SWCNT) and exhibit maximal relative change in fluorescence intensity (ΔF/F0) of up to 35-fold, with a dynamic range that spans physiological concentrations of their target brain analytes. We demonstrate that nIRCat can detect electrically and optogenetically evoked release of dopamine in brain tissue, revealing putative hotspots of activity that exhibited a log-normal distribution in size, ranging from 2 – 10 µm for mice brain tissue in the dorsomedial striatum. Furthermore, the synthetic nature of the molecular recognition platform afforded compatibility with dopamine-receptor targeting antipsychotics and psychoactive drugs and permitted studies of how such receptor-targeting drugs modulate evoked dopamine release. This assay revealed presynaptic correlates of drug activity at the level of putative dopamine release sites, which had heretofore been inaccessible to probe with existing tools. Our results suggest that nIRCat technology may uniquely support similar explorations of processes that regulate dopamine neuromodulation at the level of individual synapses, and exploration of the effects of receptor agonists and antagonists that are commonly used as psychiatric drugs as well as drugs that lead to substance use disorder. We conclude that SWCNTs can serve as versatile synthetic optical scaffolds for monitoring interneuronal chemical signaling in the brain extracellular space at spatial and temporal scales pertinent with the encoded neurochemical information.
Solid-State Diffusion Coefficient of Li Ions in Li[Ni1/2Mn3/2]O4 Determined By the Diluted Electrode Method
Authors: Sugawa Jun , Masuda Shumpei , Ariyoshi Kingo 
Published: December 2020

The input- and output-power of lithium-ion batteries strongly depend on the rate capability of the lithium insertion electrode used as positive and negative electrodes. In our previous studies, the rate capability of the electrodes have revealed that the diffusion of Li ions in the electrolyte inside the electrode is a rate-determining step [1]. Recently, the use of a dilute electrode in which a part of the active material is replaced with a spectator material makes the Li ion transport process in the solid phase rate-determining. In other words, the diluted electrode method allows to measure the rate capability of the material and to determine the solid-state Li-ion diffusion coefficient in an active material.
In this study, we investigate the dependence of the rate capability of materials on the particle size. The material used was Li[Ni1/2Mn3/2]O4 (LiNiMO), which is a 5V class positive electrode material whose rate capability have been variously changed depending on the crystal structure, particle size, and reaction mechanism. LiNiMO with different particle size was synthesized by changing the synthesis temperature from 800 ℃ to 1100 ℃. The particle size of LiNiMO increased with rising the synthesis temperature. Dilute electrodes containing 10 wt% of LiNiMO active material was prepared and the rate capability tests were carried out. The lower the synthesis temperature, the better the rate capability. The sample with the smallest particle size (> 1㎛) synthesized at 800 ℃ showed 4 times higher rate capability compared to the sample with the largest particle size (7 ㎛) synthesized at 1100 ℃. This result suggests that the smaller the particle size of the material, the shorter the diffusion distance of lithium ions in the solid phase, and thus the superior rate capability was exhibited.
In the presentation, based on the results of these rate tests, the solid-state diffusion coefficient of Li ions in the LiNiMO was determined, and the relationship between physicochemical properties such as particle size, crystal structure, and reaction mechanism of LiNiMO and the diffusion coefficient was investigated.
[1] K. Ariyoshi et al., J. Electrochem. Soc., 165, A3965-A3970 (2018).

Figure 1
Synthesis of β-Mn2V2O7 Anode Materials Using Facile Green Strategy for High Performance Rechargeable Lithium Ion Batteries
Authors: Lee Seunggyeong , Song Moonsoo , Sambandam Balaji , Alfaruqi Muhammad Hilmy , Kim Jaekook 
Published: December 2020

Vanadium-based mixed metal oxides are of interest because of their high energy density, variable oxidation states, and high specific capacities.
Within the family of manganese vanadium oxides, earth abundant β-Mn2V2O7 (MnVO) has attracted considerable attention because of its fascinating crystal structures with key building blocks of several extended M-O and V-O polyhedral units.
Herein we report the β-Mn2V2O7 (MnVO) were synthesized by a simple and cost-effective zeolitic imidazolate frame- work precipitation technique using water as the sole solvent and reported for excellent electrochemical Li storage properties. The anode delivers specific capacities of 868 and 751 mAh g-1 at rates of 500 and 2000 mAh g-1 after 180 and 400 cycles, respectively.
In-Situ EIS to Investigate Effect of C-Rate on Impedance Spectra of Positive Electrodes with Different Ratio of Conductive Additives in Lithium Ion Batteries
Authors: Kojima Fumiya , Hoshi Yoshinao , Watanabe Hikari , Shitanda Isao , Itagaki Masayuki 
Published: December 2020

Active materials, conductive additives and binders are widely used for the fabrication of positive electrodes of lithium ion batteries (LIBs). The electrochemical performance of positive electrodes is affected by the addition rate of conductive additives on the electrode 1). It is important to investigate the effect of the addition rate of conductive additives on the electrode performance of the positive electrode during charge-discharge cycle in order to develop LIBs that can charge and discharge at high C-rate. In the present study, the in-situ EIS 2) was employed to investigate the effect of C-rate on impedance spectra of positive electrode with different additive rates of conductive additives.
The positive electrode with different additive rates of acetylene black (AB) was fabricated by screen printing. The mixture of the slurry containing LiCoO2 powder, AB, polyvinylidene fluoride and N-methylpyrrolidone were screen-printed on the aluminum foil. In the present study, the positive electrode with different additive rates of AB was used for the impedance measurement. The spherical natural graphite fabricated on cupper foil was used as the negative electrode and a lithium wire was used as the reference electrode (RE). All measurements were carried out by the three-electrode cell (Toyo system co. ltd.) at room temperature in an argon atmosphere.
The 3D impedance of positive electrode, negative electrode and full cell was measured by in-situ EIS during charge and discharge. In the 3D impedance of positive electrode, three loops were observed on the Nyquist plane during charge and discharge. As the diameter of loop in the low frequency range was decreased with the increase of the state of charge (SOC), this loop may be related to the time constant composed of the charge transfer resistance R
ct and the electric double layer capacitance 2). In order to examine the effect of C-rate on impedance of positive electrode, the changes of R
ct values during charge and discharge were estimated from the instantaneous impedance at arbitrary SOC on 3D impedance of positive electrode. The relationship between C-rate and additive rates of AB on the impedance of positive electrode was discussed.
References:
1) F. Y. Su, C. H. You, Y. B. He, W. Lv, W. Cui, F. Jin, B. Li, Q. H. Yang and F. Kang, J. Mater. Chem., 20, 9644-9650 (2010).
2) M. Itagaki, K. Honda, Y. Hoshi, I. Shitanda, J. Electroanal.
Chem., 737, 78–84 (2015).
Fluoride-Ion Conductivity of La-Sr-F-S Multiple-Anion Compounds
Authors: Tachibana Shintaro , Ide Kazuto , Tojigamori Takeshi , Yamasaki Hisatsugu , Kotani Yukinari , Orikasa Yuki 
Published: December 2020

Fluoride-ion batteries using solid-state electrolytes exhibit the high theoretical energy density and one of the candidates for next-generation rechargeable batteries [1]. For fluoride-ion batteries, the ion carrier is monovalent fluoride ion, which can realize the multi-electron reactions of counter cations in active materials of fluoride compounds. However, it is far from practical use because there is no solid electrolyte which has high ionic conductivity and a wide electrochemical potential window like lithium-ion conductors. The previously reported fluoride-ion conductors such as PbSnF4 [2] and La0.9Ba0.1F2.9 [3] contain single carrier ion, fluoride ions. To our best knowledge, there is few report on the solid electrolyte materials containing multiple-anion compounds [4].
In the field of material sciences, mixed-anion compounds have recently attracted attention, and unique structures with multiple anions have been reported [5]. Compared with existing materials such as oxides and fluorides, mixed-anion compounds have the possibilities to exhibit innovative functions due to their specific crystal and coordination structure. Therefore, using multiple-anion compounds could realize much higher physical properties than ever before.
In this study, we synthesized La-Sr-F-S compounds containing fluoride and sulfides ions as anions by solid-state reaction under vacuum. The crystal structure of the synthesized compound was characterized by X-ray diffraction. In order to measure the conductivity and the fluoride-ion transport number of the synthesized compounds, electrochemical impedance spectroscopy and the DC conductivity measurement were performed, respectively. Moreover, cyclic voltammetry was performed to evaluate electrochemical potential window. In the synthesis, F－- deficient and F－-excess type of La-Sr-F-S compounds were successfully synthesized by controlling the weight ratio of starting materials. We discuss the mechanism to realize fast fluoride ion conduction comparing them.
Reference:
[1] M.A. Reddy and M. Fichitner, J. Mater. Chem, 21, 17059–17062 (2011).
[2] N. I. Sorokin, P. P. Fedorov, O. K. Nikol’skaya, O. A. Nikeeva, E. G. Rakov, and E. I. Ardashinikova, Inorg. Chem., 37, 1178-1182 (2017)
[3] C. Rongeat, M. A. Reddy, R. Witter, and M. Fichtner, ACS Appl. Mater. Interfaces, 6(3), 2103-2110 (2014).
[4] S. Mater, J. Reau, L. Rabardel, G. Demazeau, and P. Hagenmuller, Solid State Ionics, 11, 77-81(1983).
[5] H. Kageyama, K. Hayashi, K. Maeda, J.P. Attfield, Z. Hiroi, J.M. Rondinelli, and K.R. Poeppelmeier, Nature Comm., 9 772(2018)
Lithium Storage Properties of Rocksalt-Type Li-Excess Titanium Sulfides
Authors: Shinoda Miyuki , Yabuuchi Naoaki 
Published: December 2020

In recent years, the demands for lithium-ion batteries has increased rapidly all over the world. To further increase the energy density, Li-excess electrode materials which deliver higher reversible capacities have been actively studied as advanced positive electrode materials. A Li-excess sulfide, Li2TiS3, delivers a large reversible capacity on the basis of reversible anion redox.1) Li2TiS3 has the advantage of high electronic conductivity even though it is composed of Ti4+ ions without valence electrons. This is a characteristic feature of sulfides that is different from an oxide counterpart, Li2TiO3. In this study, we study factors affecting on electrode performance of Li2TiS3 and discuss reaction mechanisms as the potential high-capacity positive electrode material for lithium-ion batteries.
Li2TiS3 was prepared by mechanical milling. Li2S and TiS2 were used as precursors, and the mixture of the precursors were mixed by using a zirconia pot and zirconia balls. Crystal structures of the samples were examined by using an X-ray diffractometer. Composite electrodes consisted of 80 wt% active materials, 10 wt% acetylene black and 10 wt% polyvinylidene fluoride, pasted on aluminum foil as a current collector. Metallic lithium was used a negative electrode. The electrolyte solutions used were 1.0 M LiPF6 dissolved in ethylene carbonate:dimethyl carbonate (3:7 by volume) and 5.3 M LiFSA dissolved in trimethylphosphine as a concentrated electrolyte solution.2) Two-electrode cells were used and cycled at a rate of 20 mA g-1 at room temperature.
Figure 1 shows the X-ray diffraction patterns of the precursors and the sample after mechanical milling. From Fig. 1, diffraction lines of the starting materials with high crystallinity disappear after mechanical milling and broad diffraction lines after milling are assigned into a cation-disordered rocksalt-type structure with low crystallinity. Although Li2TiO3 is electrochemically inactive, Li2TiS3 delivers a large reversible capacity of over 300 mA h g-1 in Li cells. However, the reversible capacity of Li2TiS3 is reduced to approximately 150 mA h g-1 after the 30 cycles test with the aprotic electrolyte solution with 1 M LiPF6 as shown in Fig. 2. On the other hand, Li2TiS3 delivers a reversible capacity of 230 mA h g-1 even after 50 cycles with the concentrated electrolyte solution (5.3 M LiFSA) because dissolution of the sulfide could be suppressed for the concentrated electrolyte solution with less free solvents.3) From these results, we discuss the factors affecting electrode performance of Li2TiS3 for advanced positive electrode materials with sulfide ions.
References
(1) Atsushi Sakuda et al., Scientific Reports.
8, 15086 (2018).
(2) Jianhui Wang et al., Nature Energy.
3, 22–29 (2018).
(3) Takayuki Doi et al., ChemistrySelect.
2, 8824-8827 (2017).

Figure 1