研究者詳細 - 仁科　勇太

論文 - 仁科　勇太

分割表示 219 件中 61 - 80 件目／全件表示 >>

Graphene Oxide-Based Multi-Component Antimicrobial Hydrogels

Mohammed Zahedul Islam Nizami, Benoit Denis Louis Campeon, Akira Satoh, Yuta Nishina

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 95 ( 5 ) 713 - 720 2022年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CHEMICAL SOC JAPAN

Graphene oxide (GO)-based hydrogel composed of magnesium oxide (MgO) and povidone-iodine (PVP-I) is synthesized. GO in the hydrogel plays two roles; gelator by self-assembling and carrier for MgO and PVP-L MgO particles act as cross-linking initiators and fillers that increase the cohesion and adhesion strengths of the hydrogels. Besides, MgO promotes antibacterial activities and regulates cellular activities over the lifetime of the hydrogel. In addition, PVP-I slowly releases free iodine from the hydrogel, exhibiting germicidal activity over time. A combination of GO, MgO, and PVP-I in the hydrogel exhibit improved electrical conductivity, fluid uptake ability, water retention capacity, water vapor transmission rate, and integrity value. Furthermore, the hydrogel has shown antimicrobial properties against Staphylococcus aureus. These findings are unique and indicate that GO-based hydrogel could be a promising material for biomedical application, especially for the treatment of pathological and surgical wounds.

DOI： 10.1246/bcsj.20220017

Surface Functionalities of Graphene Oxide with Varying Flake Size

Yee Yee Khine, Xiaojun Ren, Dewei Chu, Yuta Nishina, Tobias Foller, Rakesh Joshi

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 61 ( 19 ) 6531 - 6536 2022年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

The size of graphene oxide (GO) flakes may change the chemical composition on the surface, thereby altering its intrinsic properties. The current work explored the variations of surface moieties with four different sizes: 0.3, 0.7, 20, and 42 mu m(2), which were obtained with morphological integrity under controlled fabrication technique. On the basis of comprehensive analyses, slight variations in the composition of each chemical moiety were observed. At the same time, slight fluctuations were found for both edge-to-basal plane (E/B) and carbon-to-oxygen (C/O) ratios with increasing flake size.

DOI： 10.1021/acs.iecr.2c00748

Synergic effect of graphene oxide and boron nitride on the mechanical properties of polyimide composite films 国際誌

Yi Kai Cheng, Benoit Denis Louis Campeon, Seiji Obata, Yuta Nishina

NANOSCALE ADVANCES 4 ( 10 ) 2339 - 2345 2022年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ROYAL SOC CHEMISTRY

The addition of two-dimensional (2D) materials into polymers can improve their mechanical properties. In particular, graphene oxide (GO) and hexagonal boron nitride (h-BN) are expected to be potential nanoplatelet additives for polymers. Interactions between such nanoplatelets and polymers are effective in improving the above properties. However, no report has investigated the effect of using two types of nanoplatelets that have good interaction with polymers. In this study, we fabricated polyimide (PI) films that contain two types of nanoplatelets, amine-functionalized h-BN (BN<INF>NH<INF>2</INF></INF>) and GO. We have elucidated that the critical ratio and the content of BN<INF>NH<INF>2</INF></INF> and GO within PI govern the films' mechanical properties. When the BN<INF>NH<INF>2</INF></INF>/GO weight ratio was 52 : 1 and their content was 1 wt% in the PI film, the tensile modulus and tensile strength were increased by 155.2 MPa and 4.2 GPa compared with the pristine PI film.

DOI： 10.1039/d2na00078d

Grafting redox-active molecules on graphene oxide through a diamine linker: length optimization for electron transfer

Rizwan Khan, Yuta Nishina

DALTON TRANSACTIONS 51 ( 5 ) 1874 - 1878 2022年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ROYAL SOC CHEMISTRY

A redox-active molecule is grafted on graphene oxide (GO) via successive reactions. In the first step, GO is modified with diamine, which acts as a linker for the redox-active molecule. In the second step, the redox-active molecule is attached to the amino group of the linker by amide bond formation. Through these processes GO is partially reduced, enhancing its electrochemical properties. The structure of the functionalized GO is characterized by XPS, TGA, FTIR, and CV, and applied for electrodes in supercapacitors (SCs). The distance and direction of the redox-active molecule on the electrode affect the SC performance; ethylene diamine is the most promising linker to efficiently transfer electrons from the redox-active molecule to the electrode surface.

DOI： 10.1039/d1dt03197j

Uniform coating of magnesium oxide crystal with reduced graphene oxide achieves moisture barrier performance

Akinori Saito, Seiji Obata, Yuta Nishina

Applied Surface Science 573 2022年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER

Magnesium oxide (MgO) has high thermal conductivity while keeping insulation; thus, MgO is attractive material as a filler for thermosetting or thermoplastic resins. However, MgO readily hydrates with water or moisture. Thus, the surface of MgO is coated with organic or inorganic substances. We focused on graphene oxide (GO) as a surface coating agent. It has a 2-dimensional thin sheet structure, oxygen functional groups on the surface, and negative zeta-potential. Typically, GO has been used as a support material for metal nanoparticles. In this research, GO was coated on MgO micro-crystal surface to improve the surface character of MgO. The negatively charged GO and the positively charged MgO were combined with strong interaction. 0.5 wt% GO coated MgO showed excellent moisture resistance compared to organic substances coating. Coating of MgO with GO or reduced GO (rGO) is effective to overcome the weaknesses of MgO. Due to the hydrophilicity and high thermal conductivity of rGO, MgO/rGO composite can be a filler for high moisture resistance and thermal conductivity.

DOI： 10.1016/j.apsusc.2021.151483

Oxidation-degree-dependent moisture-induced actuation of a graphene oxide film

Waka Nakanishi, Yoshihiro Yamauchi, Yuta Nishina, Masafumi Yoshio, Masayuki Takeuchi

RSC ADVANCES 12 ( 6 ) 3372 - 3379 2022年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ROYAL SOC CHEMISTRY

Multilayered films prepared from graphene oxide (GO) subjected to a single oxidation process (1GO) can actuate in response to moisture, whereas those prepared from GO subjected to two oxidation processes (2GO) lose this ability. To elucidate the origin of this difference, the structures and properties of various multilayered films and their contents were analyzed. According to atomic force microscopy images, the lateral size of the GO monolayer in 2GO (2.0 +/- 0.4 mu m) was smaller than that in 1GO (3.2 +/- 0.4 mu m), although this size difference did not affect actuation. Scanning electron microscopy images of the cross sections of both films showed fine multilayered structures and X-ray diffraction measurements showed the moisture sensitive reversible change in the interlayer distances for both films. Both films adsorbed 30 wt% moisture in 60 s with different water contents at the bottom moist sides and top air sides of the films. Nanoindentation experiments showed hardness values (1GO: 156 +/- 67 MPa; 2GO: 189 +/- 97 MPa) and elastic modulus values (1GO: 4.7 +/- 1.7 GPa; 2GO: 5.8 +/- 3.2 GPa) typical of GO, with no substantial difference between the films. On the contrary, the 1GO film bent when subjected to a weight equal to its own weight, whereas the 2GO film did not. Such differences in the macroscopic hardness of GO films can affect their moisture-induced actuation ability.

DOI： 10.1039/d1ra07773b

Design of a graphene oxide-BODIPY conjugate for glutathione depletion and photodynamic therapy

Giacomo Reina, Amalia Ruiz, Barbara Richichi, Giacomo Biagiotti, Gina E. Giacomazzo, Lucas Jacquemin, Yuta Nishina, Cecilia Menard-Moyon, Wafa T. Al-Jamal, Alberto Bianco

2D MATERIALS 9 ( 1 ) 2022年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IOP Publishing Ltd

Boron dipyrromethene derivates (BODIPYs) are promising photosensitisers (PSs) for cancer treatment using photodynamic therapy (PDT). This study investigates the functionalisation of graphene oxide (GO) with a BODIPY derivate for glutathione (GSH) depletion and PDT. The functionalisation of GO with a 3,5-dichloro-8-(4-boronophenyl) BODIPY via a diol derivatisation with the phenyl boronic acid moiety at the meso position of the BODIPY core, allowed to preserve the intrinsic properties of GO. We demonstrated that both chlorine atoms were substituted by GSH in the presence of glutathione transferase (GST), inducing a relevant bathochromic shift in the absorption/emission features and thus generating the active PS. Ex vitro assessment using cell lysates containing cytoplasmatic GST revealed the intracellular catalytic mechanism for the nucleophilic substitution of the GO-BODIPY adduct with GSH. Confocal microscopy studies showed important differences in the cellular uptake of free BODIPY and GO-BODIPY and revealed the coexistence of GO-BODIPY, GO-BODIPY-GS, and GO-BODIPY-GS(2) species inside vesicles and in the cytoplasm of the cells after 24 h of incubation. In vitro biocompatibility and safety of GO and GO-BODIPY were evaluated in 2D and 3D models of prostate adenocarcinoma cells (PC-3), where no toxicity was observed up to 100 mu g ml(-1) of GO/GO-BODIPY in all treated groups 24 h post-treatment (cell viability > 90%). Only a slight decrease to 80% at 100 mu g ml(-1) was observed after 48 h of incubation. We demonstrated the efficacy of a GO adduct containing an alpha-chlorine-substituted BODIPY for the simultaneous depletion of intracellular GSH and the photogeneration of reactive oxygen species using a halogen white light source (5.4 mW cm(-2)) with a maximum in the range of 500-800 nm, which significantly reduced cell viability (<50%) after irradiation. Our study provides a new vision on how to apply BODIPY derivates and potentiate the toxicity of PDT in prostate and other types of cancer.

DOI： 10.1088/2053-1583/ac4572

Synthesis of microporous polymers with exposed C₆₀ surfaces by polyesterification of fullerenol

Hirotomo Nishihara, Akio Harigaya, Alberto Castro-Muñiz, Mao Ohwada, Takashi Kyotani, Yuta Nishina

Chemical Communications 58 ( 50 ) 7086 - 7089 2022年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Royal Society of Chemistry (RSC)

Fullerene-based microporous polymers synthesized by polyesterification of fullerenol possess excellent stability against solvents and exposed C₆₀ surfaces confirmed by enhanced hydrogen spillover.

DOI： 10.1039/d2cc00728b

A novel mechanical plant compression system for biomass fuel and acquisition of squeezed liquid with water-soluble lignin as anti-virus materials

Toshiaki Ohara, Ken Yuasa, Kentaro Kimura, Shiho Komaki, Yuta Nishina, Akihiro Matsukawa

Journal of Material Cycles and Waste Management 25 ( 1 ) 249 - 257 2022年

掲載種別：研究論文（学術雑誌）

Plant biomass could be a viable alternative renewable resource, but the moisture content must be reduced to use it as fuel. Mechanical compression alone is generally insufficient for dehydration, necessitating the addition of thermal drying. This study develops a unique mechanical rolling compression method with high dehydration ability. The squeezed liquid was analyzed using 1H nuclear magnetic resonance (1H NMR), UV–Vis, and FT-IR indicating much water-soluble lignin. Cedar board, woody biomass, compressed more effectively than cedar chips, implying that mechanical rolling compression along vessels such as straw was important. Alpinia zerumbet, herbaceous biomass, was compressed in the same way, and the squeezed liquid contained water-soluble lignin. Pellets made from plant residues were evaluated by combustion test. The squeezed liquid with water-soluble liquid revealed a basic antiviral effect for influenza and the porcine epidemic diarrhea virus. Our developed, novel, rolling plant compression method has the potential to alter fossil fuels.

DOI： 10.1007/s10163-022-01531-5

Room-Temperature Ring-Opening Polymerization of δ-Valerolactone and ϵ-Caprolactone Caused by Uptake into Porous Pillar[5]arene Crystals 国際誌

Kenichi Kato, Koki Maeda, Motohiro Mizuno, Yuta Nishina, Shixin Fa, Shunsuke Ohtani, Tomoki Ogoshi

Angewandte Chemie - International Edition 61 ( 50 ) e202212874 2022年

記述言語：英語掲載種別：研究論文（学術雑誌）

Confined space provides a reaction platform with altered reaction rate and selectivity compared with a homogeneous solution. In this work, porous phenolic pillar[5]arene crystals were used as a reaction space to promote and perturb equilibrium between lactones and their corresponding polyesters. Immersion of porous pillar[5]arene crystals in liquid lactones induced ring-opening polymerization of δ-valerolactone and ϵ-caprolactone at room temperature because the phenolic hydroxy groups have catalytic activity via hydrogen bonds and the pillar[5]arene cavities prefer linear guests. After the reaction, pillar[5]arene and polyesters formed pseudo-polyrotaxanes.

DOI： 10.1002/anie.202212874

Synthesis and Characterization of Graphene Oxide-Cellulose Based Aerogels

Ha Le, H.K., Vy Nguyen, L.T., Ngoc Phung, T.B., Quen, K., Nishina, Y., Ha Huynh, K.P., Nguyen, T.S., Quyen Chau, N.D.

Chemical Engineering Transactions 97 2022年

The carbonization of aromatic molecules with three-dimensional structures affords carbon materials with controlled pore sizes at the Ångstrom-level

Tomoki Ogoshi, Yuma Sakatsume, Katsuto Onishi, Rui Tang, Kazuma Takahashi, Hirotomo Nishihara, Yuta Nishina, Benoît D.L. Campéon, Takahiro Kakuta, Tada Aki Yamagishi

Communications Chemistry 4 ( 1 ) 2021年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：NATURE RESEARCH

Carbon materials with controlled pore sizes at the nanometer level have been obtained by template methods, chemical vapor desorption, and extraction of metals from carbides. However, to produce porous carbons with controlled pore sizes at the Ångstrom-level, syntheses that are simple, versatile, and reproducible are desired. Here, we report a synthetic method to prepare porous carbon materials with pore sizes that can be precisely controlled at the Ångstrom-level. Heating first induces thermal polymerization of selected three-dimensional aromatic molecules as the carbon sources, further heating results in extremely high carbonization yields (>86%). The porous carbon obtained from a tetrabiphenylmethane structure has a larger pore size (4.40 Å) than those from a spirobifluorene (4.07 Å) or a tetraphenylmethane precursor (4.05 Å). The porous carbon obtained from tetraphenylmethane is applied as an anode material for sodium-ion battery.

DOI： 10.1038/s42004-021-00515-0

Bulk-scale synthesis of randomly stacked graphene with high crystallinity

Zizhao Xu, Shingo Nakamura, Taiki Inoue, Yuta Nishina, Yoshihiro Kobayashi

CARBON 185 368 - 375 2021年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD

Since the strong interlayer interaction of AB-stacked graphene in bulk form degrades the superior property of single-layer graphene, formation of randomly stacked graphene is required to apply the high performances of graphene to macroscopic devices. However, conventional methods to obtain bulk-scale graphene suffer from a low crystallinity and/or the formation of a thermodynamically stable AB-stacked structure. This study develops a novel approach to produce bulk-scale graphene with a high crystallinity and high fractions of random stacking by utilizing the porous morphology of a graphene oxide sponge and an ultrahigh temperature treatment of 1500-1800 degrees C with ethanol vapor. Raman spectroscopy indicates that the obtained bulk-scale graphene sponge possesses a high crystallinity and a high fraction of random stacking of 80%. The large difference in the random-stacking ratio between the sponge and the aggregate samples confirms the importance of accessibility of ethanol-derived species into the internal area. By investigating the effect of treatment temperature, a higher random-stacking ratio is obtained at 1500 degrees C. Moreover, the AB-stacking fraction was reduced to less than 10% by introducing cellulose nanofiber as a spacer to prevent direct stacking of graphene. The proposed method is effective for large-scale production of high-performance bulk-scale graphene. (C) 2021 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.carbon.2021.09.034

Tracking the light-driven layer stacking of graphene oxide

Masaki Hada, Satoshi Ohmura, Yuki Yamamoto, Yoshiya Kishibe, Wataru Yajima, Ryo Shikata, Tomohiro Iguchi, Keishi Akada, Shoji Yoshida, Jun ichi Fujita, Shin ya Koshihara, Yuta Nishina

Carbon 183 612 - 619 2021年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD

Layer stacking of two-dimensional (2D) materials, such as graphene and transition metal dichalcogenides, is critical for controlling their physical and transport properties. By exploiting a specific stacking order, the electronic band structures of such 2D materials can be tuned, from which unusual and exotic properties may emerge. Graphene oxide (GO) undergoes layer stacking along with its photo- and thermal-induced reduction process; however, the underlying mechanism and dynamics during its layer stacking have not been revealed. In this study, we demonstrate time-resolved electron diffraction for monitoring the structural dynamics during the layer stacking of GO induced by ultraviolet photoexcitation. The experimental results accompanied by the density functional theory calculations reveal that AB stacking of graphitic domains of GO layers coincides within ∼40 ps with photoinduced removal of the epoxy-oxygen from the basal plane of GO via the strong interactions between the GO layers.

DOI： 10.1016/j.carbon.2021.07.058

Disposable electrochemical glucose sensor based on water-soluble quinone-based mediators with flavin adenine dinucleotide-dependent glucose dehydrogenase

Jannatul Morshed, Ryo Nakagawa, Motaher M. Hossain, Yuta Nishina, Seiya Tsujimura

Biosensors and Bioelectronics 189 2021年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER ADVANCED TECHNOLOGY

Glucose level measurement is essential for the point-of-care diagnosis, primarily for persons with diabetes. A disposable electrochemical glucose sensor is constructed using flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) and redox mediator for electron transfer from the enzyme to the electrode surface. Ideally, a suitable mediator should have high water solubility, high kinetic constant, high stability, and redox potential between −0.2 and 0.1 V vs. Ag|AgCl|sat. KCl. We designed and synthesized two new quinone-based water-soluble mediators: quinoline-5,8-dione (QD) and isoquinoline-5,8-dione (IQD). The formal potentials for both QD and IQD at pH 7.0 were −0.07 V vs. Ag|AgCl|sat. KCl. The logarithms of the electron exchange rate constants (k2/(M−1 s−1)) between QD/IQD and FAD-GDH were 7.7 ± 0.1 and 7.4 ± 0.1 for QD and IQD, respectively, which are the highest value among the water-soluble mediators for FAD-GDH reported to date. Disposable amperometric glucose sensors were fabricated by dropping FAD-GDH and QD or IQD onto a test strip. The sensor achieved a linear response up to glucose concentrations of 55.5 mM. The linear response was obtained even when the mediator loading was low (0.5 nmol/strip); loading was only 0.2 mol% of glucose. The results proved that the response current was primarily controlled by glucose diffusion. In addition, the sensor using QD exhibited high stability over 3 months at room temperature.

DOI： 10.1016/j.bios.2021.113357

Grafting chelating groups on 2D carbon for selective heavy metal adsorption 国際誌

Risa Shibahara, Kazuhide Kamiya, Yuta Nishina

NANOSCALE ADVANCES 3 ( 20 ) 5823 - 5829 2021年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ROYAL SOC CHEMISTRY

Iminodiacetic acid (IDA) is a tridentate ligand, which can capture metal ions by forming two fused five-membered chelate rings. In this study, we fixed IDA moieties onto a two-dimensional nanocarbon, graphene oxide (GO), to obtain materials with high and selective adsorption of metal ions. The synthesis conditions for the GO-IDA composites were optimized, then their structures were characterized by infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and CHN elemental analysis. In addition, the heavy-metal removal efficiency and selectivity of the GO-IDA composites with different length alkyl linkers between the GO and IDA were investigated. An aqueous solution containing 10 metal ions (Al, As, B, Cd, Cr, Cu, Mn, Pb, Se, and Zn) was used as a model for contaminated water at pH 7, and the interactions of the ions with GO-IDA were in the order of Cu > Pb > As > B > Zn > Al approximate to Se. The interaction between Cu and GO-IDA was confirmed by XPS and extended X-ray absorption fine structure (EXAFS), which showed that Cu was coordinated to IDA.

DOI： 10.1039/d1na00435b

Covalent double functionalization of graphene oxide for proton conductive and redox-active functions

Rizwan Khan, Keita Miyagawa, Alberto Bianco, Yuta Nishina

Applied Materials Today 24 2021年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER

The covalent double functionalization of graphene oxide (GO) is an effective approach to tune the properties of graphene-like materials. The first step is the ring-opening reaction of epoxides by amines, followed by the second step consisting on the nucleophilic addition reaction of GO hydroxyl groups to an α,β-unsaturated carbonyl compound. The benefit of doubly functionalized GO is to possess different functions, confirmed by measuring proton conductivity and supercapacitor performance. The proton conductivity can be improved by introducing sulfonic acid and redox-active functional groups on GO, while the capacitance for supercapacitor can be increased by introducing two distinct redox-active molecules. The current study evidences that a double functionalization allow to design a multifunctional GO platform as an electrolyte membrane for fuel cells and/or an electrode material for supercapacitors.

DOI： 10.1016/j.apmt.2021.101120

Enabling the fast lithium storage of large-scalable gamma-Fe2O3/Carbon nanoarchitecture anode material with an ultralong cycle life

Sadeeq Ullah, Benoit D. L. Campeon, Shumaila Ibraheem, Ghulam Yasin, Rajesh Pathak, Yuta Nishina, Tuan Anh Nguyen, Yassine Slimani, Qipeng Yuan

JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY 101 379 - 386 2021年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE INC

Two-dimensional (2D) materials are generally expected to have superior lithium-ion (LIBs) performances compare with their bulk counterpart as they display superior specific surface area. In this context, the development of 2D maghemite would be of great interest owing to its high theoretical specific capacity, natural abundance, and relatively low cost and toxicity; however, maghemite do not have a layered crystalline structure. Herein, to overcome this hindrance, gamma-Fe2O3 has been enclosed within a 2D carbon matrix via a simple and facile synthesis strategy based on the complexation of ethylene glycol with aqueous iron species by hydrolysis and condensation reactions followed by its carbonization. As obtained 2D carbon gamma-Fe2O3 nanosheet composite (C-EG-Fe) is composed of 41.3 wt.% carbon and 10.2 wt.% Fe. When used as anode materials in LIBs, C-EG-Fe demonstrated the enhanced initial discharge capacity of 1589 mAh g(-1) at 100 mA g(-1), and outstanding ultralong cycling performance with the significant stable capacity of 700 mAh g(-1) and 230 mAh g(-1) at the higher current rate of 0.5 A g(-1) and 10 A g(-1) for more than 300 and 6000 cycles, respectively. These results enable a promising avenue to design the large-scale production of 2D C-EG-Fe sheets-based nanostructured anode materials for next-generation LIBs for largescale energy storage applications. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jiec.2021.05.045

Insights into carbon nanotube-assisted electro-oxidation of polycyclic aromatic hydrocarbons for mediated bioelectrocatalysis

Paulo Henrique M. Buzzetti, Pierre-Yves Blanchard, Emerson Marcelo Girotto, Yuta Nishina, Serge Cosnier, Alan Le Goff, Michael Holzinger

CHEMICAL COMMUNICATIONS 57 ( 71 ) 8957 - 8960 2021年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ROYAL SOC CHEMISTRY

A series of polycyclic aromatics, naphthalene, phenanthrene, perylene, pyrene, 1-pyrenebutyric acid N-hydroxysuccinimide ester (pyrene NHS) and coronene, were immobilized via pi stacking on carbon nanotube (CNT) electrodes and electro-oxidized in aqueous solutions. The obtained quinones were characterized and evaluated for the mediated electron transfer with FAD dependent glucose dehydrogenase during catalytic glucose oxidation.

DOI： 10.1039/d1cc02958d

High valence states of Pd supported on ferroelectric BaTiO3 driven by electric polarization

Tasuku Yoshida, Jun Kano, Masaichiro Mizumaki, Yusuke Tamenori, Kiyofumi Nitta, Kazuo Kato, Satoshi Hinokuma, Norihiro Oshime, Satoshi Hirose, Hitoshi Mikami, Naoshi Ikeda, Tatsuo Fujii, Yuta Nishina, Tomoko Okubo

Applied Physics Letters 119 ( 9 ) 092904 - 092904 2021年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AIP Publishing

At a metal-ferroelectric junction, it has been considered that the electric polarization of the ferroelectric material can affect the electronic structure of the neighboring metal. Here, we demonstrate that the valence state of Pd can be shifted to the unstable high value of 4+ by the electric field of electric polarization in ferroelectric BaTiO3. Study of the absorption fine structure of both hard and soft x rays revealed the existence of Pd4+ states on the surface of Pd oxide nanoparticles. The positions of Pd and oxygen atoms are shifted in opposite directions by the electric field due to the electric polarization of ferroelectric BaTiO3. The atomic displacement of Pd and O forms a zigzag structure, in which the coordination number of Pd atoms is changed from four to six, producing a quadrivalent state. This report presents experimental evidence that ferroelectric polarization can control the electronic states of neighboring metal atoms, and we suggest that using the ferroelectric support effect may produce a new type of catalyst.

DOI： 10.1063/5.0066289

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