bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rechargeable Aqueous Lithium-Ion Batteries with Molybdenum-Based Oxides As Negative Electrode Materials
Authors: Sato Yoshihiko , Yabuuchi Naoaki 
Published: December 2020

Organic electrolytes used for commercial lithium-ion batteries, like EC or DMC, are flammable, often resulting in causes of fire accidents. In 1994, an aqueous lithium-ion battery using nonflammable water as electrolyte was reported for the first time, and attention has been paid for the improved safety.1 However, the conventional aqueous electrolyte solution has a narrow electrochemical window, and improvement in energy density was, therefore, needed. In recent years, highly concentrated LiTFSA (TFSA; bis(trifluoromethyl-sulfonyl)amide) aqueous solution has been proposed as aqueous electrolyte solutions with a wider electrochemical window.2,3

In this study, we report electrochemical properties of Mo-based oxides as negative electrode materials for aqueous batteries with the concentrated aqueous electrolyte, and 21 mol kg-1 LiTFSA aqueous solution was used as electrolyte. The Mo-based oxide, Li
y
Nb2/7Mo3/7O2, 4 is used as a negative electrode for aqueous lithium-ion batteries with spinel-type manganese-based oxide, Li1.05Mn1.95O4, as a positive electrode. Charge/discharge curves of full cells, consisting of Li1.05Mn1.95O4 and Li
y
Nb2/7Mo3/7O2, are shown in Figure 1. For comparison 1 M LiPF6/EC:DMC = 3/7 by volume and 21 mol g-1 LiTFSA/H2O are used as electrolyte solutions. Both cells show good cyclability at a rate of 1000 mA g-1 and are operable as 2 V-class full cells as shown in Figure 1. Capacity retention of both cells for 1000 cycle test is also shown in Figure 2, and the full cell with the concentrated aqueous electrolyte shows comparable reversibility with aprotic electrolyte solution with similar Coulombic efficiently.
From these results, we will further discuss the possibility of Mo-based oxide as potential negative electrode materials for aqueous lithium-ion batteries.
References
(1)Wu Li, J. R. Dahn, D. S. Wainwright, Science, 264, 1115 (1994).
(2)Suo, L. et al., Science
350, 938 (2015).
(3)Yamada. et al., Nat. Energy, 1, 16129 (2016).
(4)Hoshino et al., and N. Yabuuchi, ACS Energy Lett., 2, 733 (2017).

Figure 1
Effect of Different Hydroxyapatite Coating on Photocatalytic Characteristics of Titanium Dioxide Photoanode
Authors: Nay Wunn Htoo , Sakamoto Yutaro , Motoda Shinichi , Morita Motoaki 
Published: December 2020

The photocatalytic n-type semiconductor characteristics of titanium dioxide (TiO2) has been under study for decades. We have studied the photocatalytic effect of titanium dioxide electrode such as the effect of impurities on TiO2, and the effect of heat treatment on TiO2. We also have studied the effect of dye sensitizing on TiO2 electrode with seawater as the electrolyte. In that study, we found that the hydroxyapatite (HAp) coating used for the purpose to increase the binding ability between dye and TiO2 improved the capability of TiO2 electrode. In order to clearly know the mechanism of HAp coating and to improve the effect of HAp coating on TiO2 electrode, this study is conducted by preparing different types of HAp paste for coating on TiO2 electrode.
Screen printing method was used for TiO2 layer and both manual and screen printings were used for HAp (Ca10(PO4)6(OH)2) coating for comparison. Type 329J4L stainless steel was used as a substrate for TiO2 electrode. The surface of the substrate was cleaned with ultrasonic cleaner and then the surface was passivated with HNO3 solution for 30 minutes. Double layers of TiO2 were screen printed on the substrate. The first layer was screen printed and heat treated at 150 ºC for 60 minutes. The second one after printed was heat treated at 550 ºC for 30 minutes. HAp was coated on TiO2 doubled layer. HAp paste was heat treated after printed. HAp paste was prepared from HAp powder. The powder was mixed with carboxymethyl cellulose (CMC) in various ratios. Water and alcohols are added to the mixture and well stirred to get a paste. Different types of HAp paste were prepared by changing the ratios of the constituents of the paste. The finishing was performed to get the electrodes ready for measurements in artificial seawater.
The potential measurement, polarization and power density measurements against platinum counter electrode were performed by a potentiostat in dark and irradiated conditions. The irradiation used for the experiments is a xenon lamp with 150 W and calibrated wavelength range from 250 nm to 800 nm. The lamp was calibrated so that the light intensity produced became approximately 10.5 mW/cm2. The surfaces of the electrodes before and after measurement were analysed and the microstructures of the electrodes were compared by scanning electron microscope (SEM). The photocatalytic effects of HAp were observed but the cause is still unclear. The study showed that screen printing of HAp on TiO2 electrode showed higher photopotentials than manual printing or without printing. The variations in HAp paste constituents also affected the performance of TiO2 electrodes. The power density output of TiO2 can be increased more than 2 times with HAp coating. Removal of HAp particles from the electrode surfaces were observed. Further study on new techniques for HAp paste preparation and film forming process is suggested.
Time-Domain Thermoreflectance Study on Superlattice-like Phase Changing Chalcogenide Materials
Authors: Choi Seok , Yun Hee Ju , Choi Byung Joon 
Published: December 2020

Phase change memory (PCM) has been developed as one of the next generation memory candidates due to its high read/write speeds, high densities, and non-volatile characteristics. This memory uses the phase change of the chalcogenide materials by Joule heating. However, there is a problem of requesting high reset current, thereby increasing power consumption during melt-quench process for its amorphization. As a way to solve the high reset current, interfacial PCM (iPCM) was suggested. It is based on the metastable states formed in superlattice-like GeTe/Sb2Te3 stack of high quality. This PCM operates with a reversible structural change between high and low resistance states without melt-quench process. However, if the heating from electrode is too excessive during the iPCM operation process, unwanted melting can occur and iPCM characteristics can be lost. Therefore, it is necessary to study the thermal effects of superlattice-like phase change material and electrode in order to ensure stability in conventional PCM or iPCM operation.
In this study, we conduct time-domain thermoreflectance study on the molecular-beam-epitaxially grown phase change materials; GeTe and Sb2Te3. Phase change layer was consisted of single or superlattice-like structure. TiN metal layer was used to see the thermal boundary resistance between the metal and phase change materials. Au metal layer was deposited as a photothermal transducer layer due to its stability and thermoreflectance coefficient value. Thermal conductivities of signle and superlattice-like thin films are compared to analyze the thermal effects. In addtion, heat conduction between the metallic TiN and phase change material of high quality is considered.
Structure-Controlled Perovskite Thin Layer Formation on Au Single-Crystal Substrate via Self-Assembled Monolayer of 4-Aminothiophenol
Authors: Takahari Mami , Kondo Toshihiro 
Published: December 2020

1. Introduction
In order to solve recent energy and environmental problems, construction of a photoelectric conversion device using a perovskite structure has recently attracted much attention because perovskite structure absorbs visible light very much [1]. In this type of photoelectric conversion device, it is necessary to construct on a solid substrate while maintaining the perovskite structure. In order to improve efficiency, moreover, it is important to control the interfacial structure between the solid substrate and the perovskite film by an atomic dimension. In the present study, we tried to construct a perovskite layer on a Au(100) single-crystal substrate while maintaining the perovskite structure completely and control the interfacial structure between the substrate and the perovskite layer by using a self-assembled monolayer (SAM) of 4-aminothiophenol (4-ATP) by an atomic level.
2. Experimental
Au(100) single-crystal as a substrate and 4-ATP having an amino terminal group as a SAM molecule were chosen. After annealed and quenched the Au(100) substrate, it was immersed in the hexane solution containing 1 mM 4-ATP for 3 hours at room temperature (RT). Then, the 4-ATP SAM modified Au(100) substrate was sequentially immersed in each DMF solution containing 1 mM PbBr2 and 1 mM MABr for 24 hours for 3 cycles, followed by heating at 135 °C, and then MAPbBr3 perovskite thin films were constructed on 4-ATP SAM modified Au(100) surface [2]. The structure and composition of 4-ATP SAM modified Au(100) substrate after immersion in each solution were evaluated by X-ray photoelectron spectroscopy (XPS) and the crystal structure of the constructed perovskite thin film was evaluated by surface x-ray diffraction (SXRD) as compared with XRD of the corresponding perovskite crystal.
3. Results & Discussion
Figure 1 shows the SXRD profile of the perovskite thin film and the XRD profile of the perovskite crystal. In the SXRD profile, only the (0kl) reflections such as (002) and (012) of the perovskite crystal, which was indicated by triangles in Fig. 1(a), and no diffraction peaks of the (hkl) (h is not zero) reflections such as (112) and (122), which was indicated by stars in Fig. 1(b), were observed. Based on these results, it is indicated that the constructed perovskite thin film was grown along the [100] direction, and we can conclude that it is succeeded to construct the structure-controlled perovskite thin film on the Au(100) surface.
References
[1]A. K. Jena, A. Kulkarni, and T. Miyasaka, Che
m. Rev. 119 (2019) 3036.
[2]L. Zuo, Q. Chen, N. D. Marco, Y. T. Hsieh, H. Chen, P. Sun, S. Y. Chang, H. Zhao, S. Dong, and Y. Yang, Nano Lett.17 (2017) 269.
Figure Captions
Fig. 1 (a) SXRD profile of the perovskite thin film constructed on Au(100) in the present study. (b) Powder XRD profile of the synthesized perovskite powder.

Figure 1
Mechanism of Potential Oscillation (Named Oscillation K) Induced By pH Increase at Electrode Surface in “H2O2-H2so4-Pt Electrode” System
Authors: Okada Haruki , Mukouyama Yoshiharu 
Published: December 2020

Electrochemical oscillations are attractive phenomena from the viewpoint of dynamic self-organization of molecular systems. In general, an N-shaped negative differential resistance (N-NDR) plays a crucial role for the appearance of oscillations because it gives rise to an oscillatory instability. Most of the oscillations can be classified into an N-NDR type or “hidden” N-NDR (HN-NDR) type oscillator. The former shows current oscillations under potential controlled conditions and hysteresis loops under current controlled conditions, whereas the latter shows not only current oscillations but also potential oscillations. Thus, an electrochemical system that shows potential oscillations mostly falls into an HN-NDR type oscillator.
Interestingly, the reduction of H2O2 at Pt electrodes in H2SO4 solution shows eleven types of electrochemical oscillations, named sequentially from A to K [1-3]. Oscillations H, I, J, and K appear when a salt such as Na2SO4 and K2SO4 is added to the solution. In the presence of the alkali metal ions originated from the salt, the transport rate of H+ to the electrode surface decreases because the electromigration of H+ is inhibited by the metal ions. Thus, the local pH at the electrode surface becomes strongly basic during the H2O2 reduction even though the electrolyte solution is strongly acidic (e.g., 0.1 M H2SO4). In the vicinity of the electrode surface, H2O2, which is a weak acid with a pK
a of 11.7, dissociates to form HO2
- ion. The ion is electrochemically reduced to OH- or oxidized to O2, leading to the appearance of the oscillations.
In this work, the extent of the local pH increase is estimated by using a numerical simulation and the mechanisms of oscillation K is studied based on the simulation.

REFERENCES

[1] Y. Mukouyama, H. Kawasaki, D. Hara, Y. Yamada, S. Nakanishi, J. Electrochem. Soc.,
164 (2017) H1.
[2] Y. Mukouyama, H. Kawasaki, D. Hara, Y. Yamada, S. Nakanishi, J. Electrochem. Soc.,
164 (2017) H675.
[3] R. Mizuochi, M. Kikuchi, Y. Yamada, Y. Mukouyama, S. Nakanishi, ECS Meeting Abstracts, MA2018-02, 2122 (2018).

FIGURE CAPTION

Figure 1 Current (j) - potential (U) curves for 0.1 M H2SO4 + 0.3 M H2O2 + x M Na2SO4 where x = (top) 0 and (bottom) 0.1, measured (left) under potential controlled conditions and (right) under current controlled ones.

Figure 1
Comparative Oscillatory Electro-Oxidation of Formic Acid on Palladium and on Platinum
Authors: Melle Baptista Gabriel , Romano Rafael , Altair Thiago , Varela Hamilton 
Published: December 2020

The electro-oxidation of formic acid has been extensively studied, mainly because of two reasons. From the applied perspective, formic acid has been pointed out as one of the most promising molecules to be used in fuel cells. On the other hand, from the fundamental perspective, it has been used as a model system to study the electro-oxidation of other small organic molecules [1,2]. Despite the large amount of studies concerning the electro-oxidation of formic acid, some mechanistic issues remain to be well understood. In this work, we report a comparative study of the electro-oxidation of formic acid on polycrystalline platinum and palladium electrodes under oscillatory regime. The experiments were performed under potential control mode, with an external resistance coupled between the working electrode and the potentiostat. All results are shown in terms of Phi potential, that is, the electrode potential compensated by the external resistance. On platinum, the oscillations develop between ~0.58 and ~0.80 V, with an oscillatory frequency in the range of 0.78 – 1.49 Hz. As a general trend, the potential slowly increases from ~0.58 to ~0.62 V, followed by a sudden increase to ~0.80 V. On palladium, a very different behavior was observed in oscillation’s waveforms and frequencies. The oscillations develop between ~0.25 and ~0.55 V, with an oscillatory frequency in the range of 0.17 – 0.20 Hz. At the beginning, there is an abrupt increase in the electrode potential from ~0.25 to ~0.38 V. After that, the potential slowly increases until ~0.55 V, when it falls abruptly to ~0.25 V, and the process restart. Overall, the results suggest that the surface chemistry underlying the dynamics of formic acid electro-oxidation on palladium and on platinum is considerably different, particularly under oscillatory regime. Results suggest that the surface poisoning due carbon monoxide adsorption on palladium system is different when compared to platinum, even though the reaction steps for oxidation is similar in both systems. The low frequency oscillations observed on palladium indicates a slower poisoning process on its surface. Consequently, provide us perspectives on mechanistic aspect of this system, not yet treated in much detail. Thus, a broad discussion about the mechanistic issues of those systems will be presented.
References
[1] X. Yu, P.G. Pickup, Recent advances in direct formic acid fuel cells (DFAFC), J. Power Sources. 182 (2008) 124–132. doi:10.1016/j.jpowsour.2008.03.075.
[2] A. Calderón-Cárdenas, F.W. Hartl, J.A.C. Gallas, H. Varela, Modeling the triple-path electro-oxidation of formic acid on platinum: Cyclic voltammetry and oscillations, Catal. Today. (2019). doi:10.1016/j.cattod.2019.04.054.
(Invited) Low-cost 3D Gel Printer as Soft and Wet Industrial Materials Easy Realizer Developed by Virtue of RepRap Open Source Project
Authors: Saito Azusa , Yamazaki Yuta , Watanabe Yosuke , Shiblee MD Nahin Islam , Khosla Ajit , Ogawa Jun , Kawakami Masaru , Furukawa Hidemitsu 
Published: December 2020

Soft hydrogel, which contains a amount of water and also has a unique touch feeling, will be required for practical applications around soft-matter robotics including the medical field because it has an unique softness that is close to the living body and has a biocompatibility. Among them, our SWEL developed RepRap SWIM-ER, a desktop type 3D gel printer that enables 3D free-formation of soft hydrogels. The RepRap SWIM-ER is a device that can shape the soft hydrogels into a desired shape by moving a laser pointer as the light source and irradiating the gel solution in the bathtub with ultraviolet light for photo-induced gelation. This 3D gel printer can be realized at low cost because it utilizes the results of the RepRap open source project to design the device and control it with software.
Furukawa established the “Soft 3D Co-creation Consortium” (URL: https://soft3d-c.jp) in April 2018. Considering the members of this consortium as test users, we will provide a desktop type 3D gel printer RepRap SWIM-ER. First, in the field of research and development, we will use the 3D printing of soft hydrogel materials and share the practical use cases among the consortium members At the same time, we are planning to standardize the several methods concerning both the material design of 3D gel printers and the evaluation of shaped objects.

Figure 1
(Invited) Scanning Microscopic Light Scattering with Machine Learning for Quality Assurance of 3D-Printed Hydrogels
Authors: Furukawa Hidemitsu , Ogawa Jun , Watanabe Yosuke , Shiblee MD Nahin Islam , Khosla Ajit , Kawakami Masaru 
Published: December 2020

Scanning microscopic light scattering (SMILS) is a powerful tool for the characterization of soft and wet matter, including polymer gels, polymer solutions, and the dispersion of nanometer particles. Specially the SMILS has a special advantage to overcome the inhomogenities of the soft and wet matter. For example, the network structure of polymer gels is so stable that the inhomogenities due to the fluctuation under the formation of chemical reaction, i.e. gelation, tends to be fixed in the network structure. This kind of the static inhomogeneites causes the position dependence of the observation of the polymer gels in the experiment of light scattering. The SMILS is able to scan the sample of the soft and wet matter and observes many data in different positions in the same sample to obtain the space-averaged data of the time-averaged correlation functions of scattered photons. Then the SMILS determine the ensemble-averaged correlation function.
However, through the actual experiences of the SMILS experiments, we knew that the set of many data in different positions has several bad data due to dust, stray light, and mechanical vibration. By thinning the set of data to remove the bad data, the net result of the ensemble-averaged correlation function tends to improve very well. In the previous studies, we sometimes obtained the 30-100 data in different positions and thinned out the data to remove the 1-70% based on the judgement of the observer. There is a problem that the thinned data may depend on the observer.
To overcome this problem, we tried to apply machine learning for the SMILS experiments. In the machine-learning procedure, artificial intelligence was made to learn the thinning operation of the observer as a teacher so that the same thinning operation as the observer could be performed. The below-shown figure shows one of the results of this procedure. It is shown that the raw ensemble-averaged correlation function has the ambiguous four peaks of relaxation modes. However the thinned correlation function by the machine-learning procedure will improve and show only one nice-seeming peak. We will exam the reliability of this novel automation procedure especially for the 3D-printed hydrogel samples and will establish the novel AI-aimed SMILS system to be applied for quality assurance of 3D-printed hydrogels in near future.

Figure 1
(Invited) 3D Printing and Wireless Power Transfer Systems for Soft Robotics Applications
Authors: Oruganti Sai Kiran , Khosla Ajit 
Published: December 2020

Wireless power transfer (WPT) to electrical and electronic systems is an attractive substitute to conductor wiring [1]. The problem of delivery of power to multiple sensors in an environment is well known. The conductors of these power supplies are susceptible to breakage, short circuit, electronic signal cross talk, among others [2]. Perhaps a major challenge would be in the area of soft robotics, where flexible sensors are desired. In these areas a physical wiring is going to compromise the physical flexibility of the sensors. A free positioning WPT system is going to allow the necessary flexibility as there is no physical conductor and the transceivers need not be perfectly aligned for efficient delivery of power[3].
References
[1] S. K. Oruganti and F. Bien, "Flexible wireless energy transfer systems by carbon fiber as a dielectric material: Study and experiments," 2013 IEEE Wireless Power Transfer (WPT), Perugia, 2013, pp. 159-162, doi: 10.1109/WPT.2013.6556907.
[2] S. K. Oruganti, O. Kaiyrakhmet and F. Bien, "Wireless power and data transfer system for internet of things over metal walls and metal shielded environments," 2016 URSI Asia-Pacific Radio Science Conference (URSI AP-RASC), Seoul, 2016, pp. 318-320, doi: 10.1109/URSIAP-RASC.2016.7601321.
[3] Oruganti, S.K., Liu, F., Paul, D. et al. Experimental Realization of Zenneck Type Wave-based Non-Radiative, Non-Coupled Wireless Power Transmission. Sci Rep 10, 925 (2020). https://doi.org/10.1038/s41598-020-57554-1
2D and 3D Control of Lipid Bilayer Membranes for Molecular Sensors
Authors: Yoshida Kazunari , Mitsumori Ryohei , Horii Keitaro , Takashima Akito , Nishio Izumi 
Published: December 2020

The lipid bilayer structure is the main component of cell membranes, therefore, the physical properties of such structure have been studied for many years. Recently, the applications of lipid bilayers have been studied, in addition to fundamental studies. For instance, a transistor-like device was developed (Ma et al., ACS Omega, 2019).
As a part of such studies, we show the 2D and 3D control of lipid bilayer membranes. The first one is the effect of local anesthetics, Dibucaine hydrochloride molecules, on the phase behavior of ternary lipid membranes, which corresponds to the 2D control of lipid bilayer membranes (Yoshida et al., MedChemComm, 2015). The lipid membranes composed of a saturated phospholipid, unsaturated phospholipid, and cholesterol induce lateral phase separation. We revealed that the phase behavior is affected by the insertion of local anesthetic molecules into bilayer structures. Another one is the effect of toxic polar molecules, acetonitrile molecules, on the shape of lipid bilayer vesicles, which corresponds to the 3D control of lipid bilayer membranes (Yoshida et al., Colloids Interfaces, 2018). Insertion of acetonitrile molecules induces the membrane deformation.
We are trying to utilize such behaviors for soft and bio-inspired molecular sensors. We show the trials for such applications.