Updated on 2023/10/02

写真a

 
Ikeno Hidekazu
 
Organization
Graduate School of Engineering Division of Science and Engineering for Materials, Chemistry and Biology Associate Professor
School of Engineering Department of Materials Science
Title
Associate Professor
Affiliation
Institute of Engineering
Contact information
メールアドレス
Affiliation campus
Nakamozu Campus

Position

  • Graduate School of Engineering Division of Science and Engineering for Materials, Chemistry and Biology 

    Associate Professor  2022.04 - Now

  • School of Engineering Department of Materials Science 

    Associate Professor  2022.04 - Now

Degree

  • The degree of Doctor of Engineering ( Others ) (   Kyoto University (Japan) )

  • The degree of Master of Engineering ( Others ) (   Kyoto University )

Research Areas

  • Nanotechnology/Materials / Metallic material properties  / Physical properties of metals

  • Nanotechnology/Materials / Metallic material properties  / irst principles calculations / Material design simulations

  • Nanotechnology/Materials / Inorganic materials and properties

Research Interests

  • Computational materials science

  • Core-level x-ray spectroscopy

  • Materials informatics

  • Inorganic phosphors

  • electrocatalyst

  • electron spectroscopy

  • transition metal compounds

  • Computational materials science

  • First-principles calculations

Research subject summary

  • 無機蛍光体の光学特性の理論計算

  • 計算科学に基づく電気化学触媒の反応素過程の解明

  • X線吸収スペクトルの機械学習

  • 内殼X線分光(XANES/ELNES, XPS, RIXS, XMCD)の新規理論計算手法の開発

  • 第一原理計算を用いたナノ構造・物性予測

Research Career

  • 第一原理多電子計算による蛍光体特性の予測

    Joint Research in Japan

    2020.04 - Now 

  • 機械学習と第一原理計算に基づく新規スペクトル解析技術の確立

    Individual

    2016.10 - Now 

  • 遷移金属複合酸化物における酸素発生反応・酸素還元反応プロセスの解明

    第一原理計算、電気化学触媒  Joint Research in Organization

    2014.10 - Now 

  • 鉄系酸化物磁石における添加元素の局所環境解析

    Joint Research in Japan

    2014.04 - 2017.03 

  • Accurate first-principles calculations of x-ray spectroscopy for poly-anion type cathode materials of lithium ion batteries

    First-principles calculation, X-ray absorption spectroscopy, Electron energy-loss spectroscopy, Lithium ion batteries  Individual

    2012 - 2013 

  • 内殻X線分光の相対論多電子計算手法の開発

    Individual

    2002.04 - Now 

Professional Memberships

  • The Physical Society of Japan

    2007.06 - Now   Domestic

  • Japan Institute of Metals and Materials

    2002.12 - Now   Domestic

Job Career (off-campus)

  • 内閣官房   グローバル・スタートアップ・キャンパス構想推進室   室員 (非常勤)

    2022.08 - Now

  • Cabinet Office, Goverment of Japan   Secretariat of Science, Technology and Innovation Policy

    2022.04 - Now

  • JST PRESTO

    2016.10 - 2020.03

  • Assistant Professor, Fukui Institute for Fundamental Chemistry, Kyoto University

    2011.11 - 2013.03

  • FIFC fellow, Fukui Institute for Fundamental Chemistry, Kyoto University

    2010.04 - 2011.10

  • Postdoctoral fellow, Department of Chemistry, Utrecht University

    2009.04 - 2010.03

  • Postdoctoral fellow, Graduate School of Engineering, Kyoto University

    2008.04 - 2009.03

  • Postdoctoral fellow, Graduate School of Engineering, Kyoto University

    2007.04 - 2008.03

  • Research Fellow of the Japan Society for the Promotion of Science

    2005.04 - 2007.03

▼display all

Papers

  • Extraction of Local Structure Information from X-ray Absorption Near-Edge Structure: A Machine Learning Approach

    Higashi Megumi, Ikeno Hidekazu

    MATERIALS TRANSACTIONS   64 ( 9 )   2179 - 2184   2023.09( ISSN:13459678

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    <p>In this work, we constructed machine learning models to predict structural descriptors that numerically represent the atomic structures in three dimensions from x-ray absorption near-edge structure (XANES) spectra. The neural network models that predict radial distribution functions (RDF) and orbital-field matrix (OFM), a descriptor that deals with the anisotropy of the local structure, the valence electron number of the ligand, and orbital information, were constructed. We used more than 120,000 O K-edge XAS spectra data from the Materials Project database as the training data set. We successfully constructed models that roughly predicted RDFs with 74% of the test data. Furthermore, the model that predicted OFM also captured an overview of OFM in 97% of the test data. These results demonstrate that the atomic structural information can be directly extracted from XANES spectra using neural network models.</p>

    DOI: 10.2320/matertrans.mt-mg2022028

  • Unusual Selective Monitoring of <i>N,N</i>-Dimethylformamide in a Two-Dimensional Material Field-Effect Transistor

    Akito Fukui, Keigo Matsuyama, Hiroaki Onoe, Shun Itai, Hidekazu Ikeno, Shunsuke Hiraoka, Kousei Hiura, Yuh Hijikata, Jenny Pirillo, Takahiro Nagata, Kuniharu Takei, Takeshi Yoshimura, Norifumi Fujimura, Daisuke Kiriya

    ACS Nano   17 ( 15 )   14981 - 14989   2023.07( ISSN:1936-0851

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    Publishing type:Research paper (scientific journal)  

    DOI: 10.1021/acsnano.3c03915

    PubMed

  • Rapid discovery of new Eu2+-activated phosphors with a designed luminescence color using a data-driven approach Reviewed

    Materials Advances   4 ( 1 )   231 - 239   2023.01

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    Publishing type:Research paper (scientific journal)   International / domestic magazine:International journal  

    DOI: 10.1039/d2ma00881e

  • Synergistic Effect between Fe4+ and Co4+ on Oxygen Evolution Reaction Catalysis for CaFe1-xCoxO3

    Yamada Ikuya, Tanaka Atsushi, Oda Seiji, Okazaki Yuichi, Toda Fumito, Kato Yuta, Kizawa Yuta, Oshita Masaya, Goto Manami, Morimura Amane, Ochi Asuka, Toda Kaoru, Wang Wencong, Yamamoto Hajime, Ikeno Hidekazu, Yagi Shunsuke

    MATERIALS TRANSACTIONS   accepted   2023( ISSN:13459678

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    Publishing type:Research paper (scientific journal)  

    <p>Chemical substitution is an effective way to improve electrocatalytic properties in transition metal oxides. We investigate the synergistic effect between Fe<sup>4+</sup> and Co<sup>4+</sup> ions on the catalytic activity for oxygen evolution reaction (OER) in the Fe-Co-mixed perovskite oxide CaFe<sub>1–</sub><i><sub>x</sub></i>Co<i><sub>x</sub></i>O<sub>3</sub>. The OER activity of CaFe<sub>1–</sub><i><sub>x</sub></i>Co<i><sub>x</sub></i>O<sub>3</sub> is substantially increased by small amounts of Co (Fe) doping into CaFeO<sub>3</sub> (CaCoO<sub>3</sub>), leading to the superiority compared to the pure Fe and Co perovskite oxides. The <i>x</i> dependences of the OER overpotential and specific activity for CaFe<sub>1–</sub><i><sub>x</sub></i>Co<i><sub>x</sub></i>O<sub>3</sub> (0.05 ≦ <i>x</i> ≦ 0.95) are expressed by constant offset from the weighted average between CaFeO<sub>3</sub> and CaCoO<sub>3</sub>, which can be interpreted to be the synergistic effect between Fe<sup>4+</sup> and Co<sup>4+</sup> ions on OER activity. The absence of the optimum <i>x</i> for the highest activity for CaFe<sub>1–</sub><i><sub>x</sub></i>Co<i><sub>x</sub></i>O<sub>3</sub> contrasts with the volcano-like plots reported in various mixed-metal oxides. First-principle calculations using the special quasirandom structure models on CaFe<sub>1–</sub><i><sub>x</sub></i>Co<i><sub>x</sub></i>O<sub>3</sub> (<i>x</i> = 0.03–0.5) demonstrate that about half the amount of Fe<sup>4+</sup> is electronically activated to possess smaller charge-transfer energies, corroborating the enhancement of catalytic activity in CaFe<sub>1–</sub><i><sub>x</sub></i>Co<i><sub>x</sub></i>O<sub>3</sub>. These findings provide new insight into the synergistic effects in complex transition metal oxide catalysts.</p>

    DOI: 10.2320/matertrans.mt-mg2022021

  • A Novel Diamagnetic Insulating Quadruple Perovskite Oxide YCu3Rh4O12

    Yamada Ikuya, Kato Yuta, Nakajima Hiroshi, Ikeno Hidekazu, Mori Shigeo, Kawaguchi Shogo

    MATERIALS TRANSACTIONS   accepted ( 9 )   2077 - 2081   2023( ISSN:13459678

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    Publishing type:Research paper (scientific journal)  

    <p>A novel oxide YCu<sub>3</sub>Rh<sub>4</sub>O<sub>12</sub> has been obtained using high-pressure and high-temperature conditions of 12 GPa and 1573 K. Electron diffraction and synchrotron X-ray powder diffraction data demonstrates that YCu<sub>3</sub>Rh<sub>4</sub>O<sub>12</sub> crystallizes in a cubic <i>AA</i>′<sub>3</sub><i>B</i><sub>4</sub>O<sub>12</sub>-type quadruple perovskite structure. The valence state is estimated to be Y<sup>3+</sup>Cu<sup>3+</sup><sub>3</sub>Rh<sup>3+</sup><sub>4</sub>O<sub>12</sub> by X-ray absorption spectroscopy. The electric resistivity and magnetization data prove that YCu<sub>3</sub>Rh<sub>4</sub>O<sub>12</sub> is a diamagnetic insulator, which is expected from the electron configurations of Cu<sup>3+</sup> (3d<sup>8</sup>, low spin, <i>S</i> = 0) and Rh<sup>3+</sup> (4d<sup>6</sup>, low spin, <i>S</i> = 0) ions. The first-principle calculation displays the insulating band structure for YCu<sub>3</sub>Rh<sub>4</sub>O<sub>12</sub>. The valence state transition from Ca<sup>2+</sup>Cu<sup>2.8+</sup><sub>3</sub>Rh<sup>3.4+</sup><sub>4</sub>O<sub>12</sub> to Y<sup>3+</sup>Cu<sup>3+</sup><sub>3</sub>Rh<sup>3+</sup><sub>4</sub>O<sub>12</sub> indicates that the doped electrons by the substitution of Y<sup>3+</sup> for Ca<sup>2+</sup> are not simply injected to Cu and/or Rh ions, realizing unusual charge redistributions consisting of the simultaneous Cu oxidation (Cu<sup>2.8+</sup> → Cu<sup>3+</sup>) and Rh reduction (Rh<sup>3.4+</sup> → Rh<sup>3+</sup>).</p>

    DOI: 10.2320/matertrans.mt-mg2022005

  • Narrow-Band Emitting Phosphor Na2Cs2Sr(B9O15)2:Eu2+ Discovered from Local Structure Similarity with Sulfate Phosphor Reviewed

    Shota Takemura, Yukinori Koyama, Takayuki Nakanishi, Shiro Funahashi, Naoto Hirosaki, Hidekazu Ikeno, Takashi Takeda

    The Journal of Physical Chemistry Letters   13 ( 51 )   11878 - 11882   2022.12

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    Publishing type:Research paper (scientific journal)   International / domestic magazine:International journal  

    DOI: 10.1021/acs.jpclett.2c02889

    PubMed

  • Composition-Designed Multielement Perovskite Oxides for Oxygen Evolution Catalysis Reviewed

    Yuichi Okazaki, Yushi Fujita, Hidenobu Murata, Naoki Masuyama, Yusuke Nojima, Hidekazu Ikeno, Shunsuke Yagi, Ikuya Yamada

    Chemistry of Materials   34 ( 24 )   10973 - 10981   2022.12( ISSN:0897-4756

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    Publishing type:Research paper (scientific journal)   International / domestic magazine:International journal  

    Oxygen evolution reaction (OER) catalysts play an essential role in energy-conversion electrochemical reactions. High-entropy oxides (HEOs) were recently investigated as promising candidates to realize highly active and cost-effective OER catalysts. Since the vast composition space for the HEOs needs considerable efforts to find promising catalysts, the further development beyond simple chemical compositions like equimolar ones has not been achieved yet. In this study, we conducted the fast and efficient design of the perovskite of La(Cr, Mn, Fe, Co, Ni)O3 with high OER catalytic activity using Bayesian optimization and found the relationship between chemical compositions and OER catalytic activities. The multielement perovskites with the optimized compositions exhibited much higher activities than the equimolar LaCr1/5Mn1/5Fe1/5Co1/5Ni1/5O3, which was previously reported as an active catalyst. Bayesian optimization adjusted the concentrations of OER active elements of Fe, Co, and Ni in high contents to enhance the catalytic activities. The optimization also indicates that the OER inactive elements (Cr and Mn) in perovskites even promote the OER activities. These findings suggest the solution of data-based predictions to improve catalytic performances in multielement transition-metal oxides.

    DOI: 10.1021/acs.chemmater.2c02986

  • Structural phase transition in cobalt oxyfluoride Co3Sb4O6F6 observed by high-resolution synchrotron and neutron diffraction Reviewed

    Seiya Shimono, Hiroki Ishibashi, Yusuke Nagayoshi, Hidekazu Ikeno, Shogo Kawaguchi, Masato Hagihala, Shuki Torii, Takashi Kamiyama, Katsuya Ichihashi, Sadafumi Nishihara, Katsuya Inoue, Yui Ishii, Yoshiki Kubota

    Journal of Physics and Chemistry of Solids   163   110568 - 110568   2022.04( ISSN:0022-3697

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    Publishing type:Research paper (scientific journal)   International / domestic magazine:International journal  

    DOI: 10.1016/j.jpcs.2021.110568

  • Narrow-band phosphor K2ZnP2O7:Eu2+ discovered using local structure similarity Reviewed

    Shota Takemura, Yukinori Koyama, Takayuki Nakanishi, Shiro Funahashi, Naoto Hirosaki, Hidekazu Ikeno, Takashi Takeda

    Scripta Materialia   215   114686 - pp.1-5   2022.03( ISSN:1359-6462

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    Publishing type:Research paper (scientific journal)   Kind of work:Joint Work   International / domestic magazine:International journal  

    A new narrow-band emitting phosphor K2ZnP2O7:Eu2+ was discovered by extracting promising crystal structures from a database. Regarding the local structures consisting of the central cation and surrounded ligands extracted from the crystal structure, we obtained the quantitative dissimilarity between the local structures and visualized the data as a 2D scatter plot using the t-SNE method. As a result, one of the K-sites of K2ZnP2O7 was located near the reference local structure Ba-site of the known narrow-band phosphor BaSi2O2N2:Eu2+ in the scatter plot. We synthesized K2ZnP2O7:Eu2+ and measured the luminescence properties. K2ZnP2O7:Eu2+ showed a narrow-band emission at 440 nm with a full width at half maximum of 30 nm.

    DOI: 10.1016/j.scriptamat.2022.114686

  • Highly active postspinel-structured catalysts for oxygen evolution reaction Reviewed

    Yuichi Okazaki, Seiji Oda, Akihiko Takamatsu, Shogo Kawaguchi, Hirofumi Tsukasaki, Shigeo Mori, Shunsuke Yagi, Hidekazu Ikeno, Ikuya Yamada

    RSC Advances   12 ( 9 )   5094 - 5104   2022.02

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    Authorship:Corresponding author   Publishing type:Research paper (scientific journal)   International / domestic magazine:International journal  

    Postspinel-structured oxides, CaB<sub>2</sub>O<sub>4</sub> (B = Cr<sup>3+</sup>, Mn<sup>3+</sup>, and Fe<sup>3+</sup>), have exhibited systematically higher catalytic activities in the oxygen evolution reaction (OER) than nominally conventional counterparts of perovskite LaBO<sub>3</sub> and spinel ZnB<sub>2</sub>O<sub>4</sub>.

    DOI: 10.1039/d2ra00448h

  • Dissimilarity measure of local structure in inorganic crystals using Wasserstein distance to search for novel phosphors Reviewed

    Shota Takemura, Takashi Takeda, Takayuki Nakanishi, Yukinori Koyama, Hidekazu Ikeno, Naoto Hirosaki

    Science and Technology of Advanced Materials   22 ( 1 )   185 - 193   2021.12( ISSN:1468-6996

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    Publishing type:Research paper (scientific journal)  

    DOI: 10.1080/14686996.2021.1899555

  • Ultralarge Photoluminescence Enhancement of Monolayer Molybdenum Disulfide by Spontaneous Superacid Nanolayer Formation Reviewed International coauthorship

    Yuki Yamada, Yan Zhang, Hidekazu Ikeno, Keisuke Shinokita, Takeshi Yoshimura, Atsushi Ashida, Norifumi Fujimura, Kazunari Matsuda, Daisuke Kiriya

    ACS Applied Materials & Interfaces   13 ( 21 )   25280 - 25289   2021.06( ISSN:1944-8244

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    Publishing type:Research paper (scientific journal)   International / domestic magazine:International journal  

    Due to the direct band gap nature, extensive studies have been conducted to improve the optical behavior in monolayer transition metal dichalcogenides (TMDCs) with a formula of MX2 (M = Mo, W; X = S, Se, Te). One of the strongest modulating agents of optical behavior is a molecular superacid treatment; however, the chemical event has not been unveiled. Also, the engineering protocol for keeping the treatment is immature. In this work, we systematically study the superacid treatment procedures on monolayer molybdenum disulfide (MoS2) and propose that the interaction, a hydrophilic interaction, between the superacid molecule and MoS2 surface would be critical. As a result of the interaction, the superacid molecules spontaneously form an acidic layer with the thickness of several nanometers on the surface. The power-dependent photoluminescence (PL) measurement indicates the edge of MoS2 flake is more effective and electronically modulated by the treatment. By understanding the superacid nanolayer formation by the treatment, we succeeded in maintaining the ultrastrong PL in the superacid-treated MoS2 for more than 30 days in the ambient air by encapsulation with transparent organic polymers. This study advances the understanding and designing applications of strong luminescent properties in the superacid-treated TMDCs and paves the way toward engineering exciton dynamics and an experimental platform for treating multibody states.

    DOI: 10.1021/acsami.1c04980

  • Metamagnetic Behavior in a Quadruple Perovskite Oxide Reviewed

    Yuichi Okazaki, Yuta Kato, Yuta Kizawa, Seiji Oda, Kai Uemura, Takuya Nishio, Fuminari Fujii, Shintaro Fujinari, Masaya Kinoshita, Takao Odake, Hayato Togano, Takashi Kamegawa, Shogo Kawaguchi, Hajime Yamamoto, Hidekazu Ikeno, Shunsuke Yagi, Kouhei Wada, Kyo-Hoon Ahn, Atsushi Hariki, Ikuya Yamada

    Inorganic Chemistry   60 ( 10 )   7023 - 7030   2021.05( ISSN:0020-1669

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    A cubic quadruple perovskite oxide CeMn3Cr4O12 has been synthesized under high-pressure and high-temperature conditions of 8 GPa and 1273 K. The X-ray absorption spectroscopy reveals that the Ce ions are in a trivalent state, as represented by the ionic model of Ce3+Mn3+3Cr3+4O12. The magnetic study demonstrates three independent antiferromagnetic transitions attributed to Ce (∼10 K), Mn (46 K), and Cr (133 K) ions. Furthermore, a magnetic field-induced antiferromagnetic-to-ferromagnetic (metamagnetic) transition of Ce3+ 4f moments is observed at low temperatures below 20 K, exhibiting a rare example of metamagnetism in the Ce3+-oxides. This finding represents that the 3d-electron magnetic sublattices play a role in the metamagnetism of 4f-electron magnetic moments, demonstrating a new aspect of the 3d-4f complex electron systems.

    DOI: 10.1021/acs.inorgchem.0c03432

    PubMed

  • Metamagnetic Behavior in a Quadruple Perovskite Oxide Reviewed

    Yuichi Okazaki, Yuta Kato, Yuta Kizawa, Seiji Oda, Kai Uemura, Takuya Nishio, Fuminari Fujii, Shintaro Fujinari, Masaya Kinoshita, Takao Odake, Hayato Togano, Takashi Kamegawa, Shogo Kawaguchi, Hajime Yamamoto, Hidekazu Ikeno, Shunsuke Yagi, Kouhei Wada, Kyo-Hoon Ahn, Atsushi Hariki, and Ikuya Yamada

    Inorganic Chemistry 雑誌 American Chemical Society   60 ( 10 )   2021.05

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    Kind of work:Joint Work  

  • 2p x-ray absorption spectroscopy of 3d transition metal systems Reviewed

    Frank M.F. de Groot, Hebatalla Elnaggar, Federica Frati, Ru-pan Wang, Mario U. Delgado-Jaime, Michel van Veenendaal, Javier Fernandez-Rodriguez, Maurits W. Haverkort, Robert J. Green, Gerrit van der Laan, Yaroslav Kvashnin, Atsushi Hariki, Hidekazu Ikeno, Harry Ramanantoanina, Claude Daul, Bernard Delley, Michael Odelius, Marcus Lundberg, Oliver Kuhn, Sergey I. Bokarev, Eric Shirley, John Vinson, Keith Gilmore, Mauro Stener, Giovanna Fronzoni, Piero Decleva, Peter Kruger, Marius Retegan, Yves Joly, Christian Vorwerk, Claudia Draxl, John Rehr, Arata Tanaka

    Journal of Electron Spectroscopy and Related Phenomena   249   147061 - 147061   2021.05( ISSN:0368-2048

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    Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.elspec.2021.147061

  • 四重ペロブスカイト酸化物の酸素発生触媒特性 Reviewed

    山田幾也、池野豪一、八木俊介

    触媒 雑誌 触媒学会   63 ( 2 )   2021.04

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    Kind of work:Joint Work  

  • Dissimilarity measure of local structure in inorganic crystals using Wasserstein distance to search for novel phosphors Reviewed

    Shota Takemura, Takashi Takeda, Takayuki Nakanishi, Yukinori Koyama, Hidekazu Ikeno, Naoto Hirosaki

    Science and Technology of Advanced Materials 雑誌 Taylor & Francis   22 ( 1 )   2021.04

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    Kind of work:Joint Work  

  • 2p x-ray absorption spectroscopy of 3d transition metal systems Reviewed

    Frank M.F. de Groot, Hebatalla Elnaggar, Federica Frati, Ru-pan Wang, Mario U. Delgado-Jaime, Michel van Veenendaal, Javier Fernandez-Rodriguez, Maurits W. Haverkort, Robert J. Green, h, Gerrit van der Laan, Yaroslav Kvashnin, Atsushi Hariki, Hidekazu Ikeno, Harry Ramanantoanina, Claude Daul, Bernard Delley, Michael Odelius, Marcus Lundberg, Oliver Kuhn, Sergey I. Bokarev, Eric Shirley, John Vinson, Keith Gilmore, Mauro Stener, Giovanna Fronzoni, Piero Decleva, Peter Kruger, Marius Retegan, Yves Joly, Christian Vorwerk, Claudia Draxl, John Rehr, Arata Tanaka

    Journal of Electron Spectroscopy and Related Phenomena 雑誌 Elsevier   249   2021.04

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    Kind of work:Joint Work  

  • Reduced-Shifted Conjugate-Gradient Method with Seed Switching for Calculating X-ray Absorption Spectra

    Hidekazu Ikeno, Masato Urasaki

    MATERIALS TRANSACTIONS   61 ( 8 )   1462 - 1467   2020.08( ISSN:1345-9678

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    Authorship:Lead author, Corresponding author   Publishing type:Research paper (scientific journal)  

    DOI: 10.2320/matertrans.mt-mn2019044

  • Reduced-Shifted Conjugate-Gradient Method with Seed Switching for Calculating X-ray Absorption Spectra Reviewed

    Hidekazu Ikeno and Masato Urasaki

    Materials Transactions 雑誌 The Japan Institute of Metals and Materials   61 ( 8 )   2020.07

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    Kind of work:Joint Work  

  • Enhanced Catalytic Activity and Stability of the Oxygen Evolution Reaction on Tetravalent Mixed Metal Oxide Reviewed

    Ikuya Yamada, Masaya Kinoshita, Seiji Oda, Hirofumi Tsukasaki, Shogo Kawaguchi, Kengo Oka, Shigeo Mori, Hidekazu Ikeno, Shunsuke Yagi

    Chemistry of Materials   32 ( 9 )   3893 - 3903   2020.05( ISSN:0897-4756

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    Publishing type:Research paper (scientific journal)  

    The oxygen evolution reaction (OER) is a crucial energy conversion reaction for achieving a sustainable society. Highly active OER catalysts were reported in Fe-Co mixed oxides such as perovskite-type Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) and brownmillerite-type Ca2FeCoO5. The synergistic effects of Fe-Co mixing on the OER activity are expected in these oxides. However, the details have not been discussed yet because of their structure randomness. In this study, we examine Fe-Co mixing effects on OER catalytic activity for several perovskite and brownmillerite oxides with trivalent and tetravalent Fe and Co ions. Regardless of crystal structures and valence states, the Fe-Co mixing enhances the OER activities compared to the parent compounds. In particular, CaFe0.5Co0.5O3, a perovskite oxide consisting of Fe4+ and Co4+ ions, displays a significant increase in OER activity, which is comparable to BSCF, together with the enhancement of stability. The electronic state of CaFe0.5Co0.5O3 obtained by density-functional theory calculation with the special quasirandom structure model exhibits the existence of active sites with smaller charge-transfer energies than the parent compounds, CaFeO3 and CaCoO3. This finding proposes that the various structural and electronic environments around transition metal ions induced by random distributions of constituent metals contributes to dispersed electronic band structures, leading to highly active sites.

    DOI: 10.1021/acs.chemmater.0c00061

  • Enhanced Catalytic Activity and Stability of the Oxygen Evolution Reaction on Tetravalent Mixed Metal Oxide Reviewed

    Ikuya Yamada, Masaya Kinoshita, Seiji Oda, Hirofumi Tsukasaki, Shogo Kawaguchi, Kengo Oka, Shigeo Mori, Hidekazu Ikeno, and Shunsuke Yagi

    Chemistry of Materials 雑誌 American Chemical Society   32   2020.04

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    Kind of work:Joint Work  

  • Highly active hydrogen evolution catalysis on oxygen-deficient double-perovskite oxide PrBaCo2O2−δ

    Hayato Togano, Kaisei Asai, Seiji Oda, Hidekazu Ikeno, Shogo Kawaguchi, Kengo Oka, Kouhei Wada, Shunsuke Yagi and Ikuya Yamada

    Materials Chemistry 雑誌 The Royal Society of Chemistry   4 ( 5 )   2020.03

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    Kind of work:Joint Work  

  • Highly active hydrogen evolution catalysis on oxygen-deficient double-perovskite oxide PrBaCo2O6−δ Reviewed

    Hayato Togano, Kaisei Asai, Seiji Oda, Hidekazu Ikeno, Shogo Kawaguchi, Kengo Oka, Kouhei Wada, Shunsuke Yagi, Ikuya Yamada

    Materials Chemistry Frontiers   4 ( 5 )   1519 - 1529   2020

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    Publishing type:Research paper (scientific journal)  

    Efficient hydrogen evolution on water splitting is a crucial issue to achieve a sustainable society based on renewable energy. Highly active and cost-effective catalysts for oxygen/hydrogen evolution reactions (OERs/HERs) are desired to suppress the intrinsically significant overpotential of these reactions. Perovskite-related transition-metal oxides have been widely investigated as promising candidates for electrochemical catalysts, whereas their complex composition and structure inhibit the elucidation of essential factors for activating HER. Herein, we report a systematic study on predominant factors affecting HER catalysis for Co-containing perovskite-related oxides. The A-site-ordered double perovskite oxide PrBaCo O exhibits HER activity with a volcano-type plot associated with oxygen deficiency content, and shows the highest activity at a moderate value of δ = 0.2, in addition to the significant superiority to the simple ABO -type perovskite, ACoO (A = La, La Ca , Ca). Based on the Tafel slope, electric conductivity, and charge-transfer resistance analyses, we have found that complementary factors dominate the HER catalysis; Co-O covalency and water dissociation site, which are respectively induced by high Co valence and oxygen deficiency. This finding provides new insight into the rational design of transition-metal oxide catalysts for HER. 2 6-δ 3 3 0.5 0.5

    DOI: 10.1039/D0QM00056F

  • Systematic Study of Descriptors for Oxygen Evolution Reaction Catalysis in Perovskite Oxides Reviewed

    Ikuya Yamada, Akihiko Takamatsu, Kaisei Asai, Takuto Shirakawa, Hideo Ohzuku, Akihiro Seno, Tasuku Uchimura, Hiroshi Fujii, Shogo Kawaguchi, Kouhei Wada, Hidekazu Ikeno, and Shunsuke Yagi

    The Journal of Physical Chemistry C 雑誌 ACS Publications   122 ( 49 )   2018.12

  • mxpfit: A library for finding optimal multi-exponential approximations Reviewed

    Hidekazu Ikeno

    Computer Physics Communications 雑誌 Elsevier   230   2018.09

  • Synergistically Enhanced Oxygen Evolution Reaction Catalysis for Multielement Transition-Metal Oxides Reviewed

    I. Yamada, A. Takamatsu, K. Asai, H. Ohzuku, T. Shirakawa, T. Uchimura, S. Kawaguchi, H. Tsukasaki, S. Mori, K. Wada, H. Ikeno, and S. Yagi

    ACS Applied Energy Materials 雑誌 ACS Publications   1 ( 8 )   2018.08

  • Ab-initio Multiplet Calculations Using Iterative Algorithms for X-ray Absorption Spectra at Transition Metal L2,3-Edges Reviewed

    Masato Urasaki, and Hidekazu Ikeno

    Materials Transactions 雑誌 Japan Institute of Metals   59 ( 7 )   2018.07

  • 共鳴非弾性軟X線散乱の磁気円二色性による磁性研究 Reviewed

    宮脇淳、菅滋正、藤原秀紀、池野豪一、原田慈久

    放射光 日本放射光学会   31 ( 6 )   2018.06

  • Density functional calculations of the Mössbauer parameters in hexagonal ferrite SrFe12O19

    Hidekazu Ikeno

    Physica B 雑誌 Elsevier   532   2018.03

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    Kind of work:Single Work  

  • Spherical Bessel transform via exponential sum approximation of spherical Bessel function Reviewed

    Hidekazu Ikeno

    Journal of Computational Physics 雑誌 Elsevier   355   2018.02

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    Kind of work:Single Work  

  • Complementary evaluation of structure stability of perovskite oxides using bond-valence and density-functional-theory calculations Reviewed

    Ikuya Yamada, Akihiko Takamatsu, Hidekazu Ikeno

    Science and Technology of Advanced Materials 雑誌 Taylor and Francis   19 ( 1 )   2018.02

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    Kind of work:Joint Work  

  • Oxygen Evolution via the Bridging Inequivalent Dual-Site Reaction: First-Principles Study of a Quadruple-Perovskite Oxide Catalyst Reviewed

    Takamatsu Akihiko, Ikuya Yamada, Shunsuke Yagi, Hidekazu Ikeno

    The Journal of Physical Chemistry C 雑誌 ACS Publications   121 ( 51 )   2017.12

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    Kind of work:Joint Work  

  • Dzyaloshinskii-Moriya interaction in α-Fe2O3 measured by magnetic circular dichroism in resonant inelastic soft x-ray scattering Reviewed

    Jun Miyawaki, Shigemasa Suga, Hidenori Fujiwara, Masato Urasaki, Hidekazu Ikeno, Hideharu Niwa, Hisao Kiuchi, and Yoshihisa Harada

    American Physical Society 雑誌   96   2017.12

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    Kind of work:Joint Work  

  • Basics and applications of ELNES calculations Reviewed

    Hidekazu Ikeno, Teruyasu Mizoguchi

    Oxford University Press on behalf of Japanese Society of Microscopy 雑誌   66 ( 5 )   2017.09

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    Kind of work:Joint Work  

  • Covalency Competition in the Quadruple Perovskite CdCu3Fe4O12 Reviewed

    Ikuya Yamada, Akihiko Takamatsu, Naoyuki Hayashi, Hidekazu Ikeno

    Inorganic Chemistry 雑誌 ACS Publications   56 ( 15 )   2017.08

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    Kind of work:Joint Work  

  • Bifunctional Oxygen Reaction Catalysis of Quadruple Manganese Perovskites

    Ikuya Yamada, Hiroshi Fujii, Akihiko Takamatsu, Hidekazu Ikeno, Kouhei Wada, Hirofumi Tsukasaki, Shogo Kawaguchi, Shigeo Mori, and Shunsuke Yagi

    Advanced Materials 雑誌 Wiley   29 ( 4 )   2017.01

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    Kind of work:Joint Work  

  • Evidence of Charge Transfer and Orbital Magnetic Moment in Multiferroic CuFeO2 Reviewed

    Yasuo Narumi, Tetsuya Nakamura, Hidekazu Ikeno, Noriki Terada, Takayuki Morioka, Kota Saito, Hideaki Kitazawa, Koichi Kindo, Hiroyuki Nojiri

    The Physical Society of Japan 雑誌   85   2016.11

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    Kind of work:Joint Work  

  • First-principles analysis of X-ray magnetic circular dichroism for transition metal complex oxides Reviewed

    Hidekazu Ikeno

    Journal of Applied Physics 雑誌 American Institute of Physics   120   2016.10

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    Kind of work:Single Work  

  • First-principles calculations of the OH adsorption energy on perovskite oxide

    Hideo Ohzuku, Hidekazu Ikeno, Ikuya Yamada, Shunsuke Yagi

    AIP Conference Proceedings 雑誌 American Institute of Physics   1763   2016.08

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    Kind of work:Joint Work  

  • Ab-Initio Multiplet Calculations of Fe-L2,3 X-ray Absorption Spectra in LiFePO4 and FePO4 Reviewed

    Hidekazu Ikeno

    Materials Transactions 雑誌 The Japan Institute of Metals and Materials   56 ( 9 )   2015.05

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    Kind of work:Single Work  

  • Impact of local strain on Ti-L2,3 electron energy-loss near-edge structures of BaTiO3: a first-principles multiplet study Reviewed

    Shirou Ootsuki, Hidekazu Ikeno, Yuji Umeda, Yu Yonezawa, Hiroki Moriwake, Akihide Kuwabara, Osamu Kido, Satoko Ueda, Isao Tanaka, Yoshinori Fujikawa, Teruyasu Mizoguchi

    Microscopy 雑誌 Oxford University Press on behalf of Japanese Society of Microscopy   63 ( 3 )   2014.04

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    Kind of work:Joint Work  

  • Magnetic structures of FeTiO3-Fe2O3 solid solution thin films studied by soft X-ray magnetic circular dichroism and ab initio multiplet calculations Reviewed

    H. Hojo, K. Fujita, H. Ikeno, T. Matoba, T. Mizoguchi, I. Tanaka, T. Nakamura, Y. Takeda, T. Okane, and K. Tanaka

    Applied Physics Letters 雑誌 American Institute of Physics   104   2014.03

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    Kind of work:Joint Work  

  • Mn L2,3-edge X-ray absorption spectroscopic studies on charge-discharge mechanism of Li2MnO3 Reviewed

    Kei Kubobuchi, Masato Mogi, Hidekazu Ikeno, Isao Tanaka, Hideto Imai, and Teruyasu Mizoguchi

    Applied Physics Letters 雑誌 American Institute of Physics   104   2014.02

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    Kind of work:Joint Work  

  • Zr coordination change during crystallization of MgO–Al2O3–SiO2–ZrO2 glass ceramics Reviewed

    Christian Patzig, Thomas Höche, Yongfeng Hu, Hidekazu Ikeno, Michael Krause, Marc Dittmer, Antje Gawronski, Christian Rüssel, Isao Tanaka, Grant S. Henderson

    Journal of Non-Crystalline Solids 雑誌 Elsevier   384   2014.01

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    Kind of work:Joint Work  

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MISC

  • 四重ペロブスカイト酸化物の酸素発生触媒特性

    山田幾也, 池野豪一, 八木俊介

    触媒   63 ( 2 )   83 - 88   2021

Presentations

  • Narrow-band emitting phosphor Na2Cs2Sr(B9O15)2:Eu2+ from local structure similarity Domestic conference

    Takashi Takeda, Shota Takemura, Yukinori Koyama, Takayuki Nakanishi, Shiro Funahashi, Naoto Hirosaki, Hidekazu Ikeno

    2023.03 

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    Presentation type:Oral presentation (general)  

  • Exploration of New Green-Emitting Eu2+-Activated Phosphors Using Machine Learning Domestic conference

    Yukinori Koyama, Hidekazu Ikeno, Shiro Funahashi, Masamichi Harada, Takashi Takeda, Naoto Hirosaki

    2023.03 

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    Presentation type:Oral presentation (general)  

  • Synergy effect of B-site mixing of LaBO3 for bifunctional oxygen electrocatalytic activities International conference

    S. Hiraoka, H. Ikeno, I. Yamada, S. Yagi

    The 32nd Annual Meeting of MRS-J  2022.12  MRS-J

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    Presentation type:Poster presentation  

    Venue:Yokohama, Japan  

  • Catalytic activity for oxygen evolution reaction in RNiO3 (R = La, Pr, Nd, Sm, Gd, Y, Lu) possessing metal-insulator transition International conference

    S. Asakura, T. Uchimura, I. Yamada, S. Yagi, H. Ikeno

    The 32nd Annual Meeting of MRS-J  2022.12  MRS-J

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    Presentation type:Poster presentation  

    Venue:Yokohama, Japan  

  • High-pressure synthesis and oxygen evolution reaction activity of Fe4+-Mn4+-mixed perovskite oxide CaFe1-xMnxO3 International conference

    Asuka Ochi, Ikuya Yamada, Sogo Asakura, Hidekazu Ikeno, Shunsuke Yagi

    6th International Symposium on Frontiers in Materials Science  2022.11 

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    Presentation type:Poster presentation  

    Venue:Phu Quoc, Vietnam  

  • Bayesian Design of High Entropy Oxide for Active Oxygen Evolution Catalysis International conference

    Yuichi Okazaki, Yushi Fujita, Hidenobu Murata, Naoki Masuyama, Yusuke Nojima, Hidekazu Ikeno, Ikuya Yamada, Shunsuke Yagi

    6th International Symposium on Frontiers in Materials Science  2022.11 

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    Presentation type:Oral presentation (general)  

    Venue:Phu Quoc, Vietnam  

  • Extraction of structural descriptors from X-ray absorption spectra: machine learning approaches International conference

    Megumi Higashi, Hidekazu Ikeno

    6th International Symposium on Frontiers in Materials Science  2022.11 

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    Presentation type:Poster presentation  

    Venue:Phu Quoc, Vietnam  

  • Discovery of new narrow-band phosphor using dissimilarity of local structures Domestic conference

    Discovery of new narrow-band phosphor using dissimilarity of local structures

    2022.09 

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    Presentation type:Oral presentation (invited, special)  

  • 第一原理計算に基づくペロブスカイト型関連酸化物の酸素発生反応・酸素還元反応触媒特性 Domestic conference

    池野豪一

    ファインセラミックスセンター講演会  2022.03  日本ファインセラミックスセンター

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    Presentation type:Public lecture, seminar, tutorial, course, or other speech  

    Venue:オンライン  

  • Discovery of narrow-band phosphor K2ZnP2O7:Eu2+ by local structures similarity Domestic conference

    Shota Takemura, Yukinori Koyama, Takayuki Nakanishi, Funahashi Shiro, Naoto Hirosaki, Hidekazu Ikeno, Takashi Takeda

    2022.03 

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    Presentation type:Oral presentation (general)  

  • Evaluation of similarity of local structures in inorganic crystals for novel phosphors search International conference

    Shota Takemura, Takashi Takeda, Takayuki Nakanishi, Yukinori Koyama, Hidekazu Ikeno, Naoto Hirosaki

    Materials Research Meeting 2021 (MRM2021)  2021.12 

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    Presentation type:Poster presentation  

  • Vibrational mode analysis and quantitative evaluation of Stokes shift of Eu2+-doped phosphors International conference

    Kousei Hiura, Hidekazu Ikeno

    Materials Research Meeting 2021 (MRM2021)  2021.12  The Materials Research Society of Japan

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    Presentation type:Poster presentation  

  • ベイズ最適化を用いた酸素発生触媒用高エントロピー酸化物の高性能化 Domestic conference

    藤田侑志、岡崎湧一、森村天音、村田秀信、増山直輝、能島裕介、池野豪一、八木俊介、山田幾也

    2021年度第3回関西電気化学研究会  2021.12 

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    Presentation type:Poster presentation  

  • Spectroinformatics: a new analysis scheme for X-ray absorption spectroscopy Invited International conference

    Hidekazu Ikeno

    International Workshop on Materials Science  2021.10  大阪府立大学

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    Presentation type:Poster presentation  

  • Quantitative evaluation of Stokes shift in Eu2+-doped phosphors based on density Domestic conference

    Kousei Hiura, Takashi Takeda, Yukinori Koyama, Hidekazu Ikeno

    2021.09 

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    Presentation type:Poster presentation  

  • Evaluation of catalytic activity of LaMn0.5Co0.5O3 for oxygen reduction reaction by first-principles calculations Domestic conference

    S. Hiraoka, S. Osaki, I. Yamada, S. Yagi, H. Ikeno

    2021.09 

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    Presentation type:Poster presentation  

  • Effect of B-site mixture in oxygen evolution catalyst ABO3 Domestic conference

    S. Osaki, I. Yamada, S. Yagi, H. Ikeno

    2021.09 

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    Presentation type:Poster presentation  

  • Extraction of crystal structure from database using the dissimilarity of local structures Domestic conference

    2021.09 

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    Presentation type:Poster presentation  

  • Verification of Co site preference of La-Co-substituted M-type ferrite by first-principles calculation Domestic conference

    R. Kobayashi, T. Waki, H. Ohta, H. Ikeno, Y. Tabata, H. Nakamura

    The 45th Annual Conference on MAGNETICS in Japan  2021.08 

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    Presentation type:Poster presentation  

  • 夾雑溶液下における2次元半導体 MoS2とアミド系分子間の特異的相互作用 Domestic conference

    福井暁人、尾上弘晃、板井駿、石倉恵子、池野豪一、長田貴弘、土方優、Jenny Pirillo、吉村武、芦田淳、藤村紀文、桐谷乃輔

    日本化学会 第101春季年会  2021.03  日本化学会

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    Presentation type:Poster presentation  

  • 機械学習によるスペクトル解析の高度化 Invited Domestic conference

    池野豪一

    日本化学会 第101春季年会  2021.03  日本化学会

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    Presentation type:Poster presentation  

  • 四重ペロブスカイト型酸化物CaCu3Fe4O12の酸素発生触媒活性 Domestic conference

    八木俊介,和田光平,結城潤一,劉偉,池野豪一,山田幾也

    日本セラミックス協会第33回秋季シンポジウム  2020.09 

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    Presentation type:Poster presentation  

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Collaborative research (seeds) keywords

  • X線吸収分光、電子線エネルギー損失分光の理論解析手法

  • 第一原理計算電子状態計算プログラムの利用法

Outline of collaborative research (seeds)

  • Theoretical analysis for the core-level x-ray spectroscopy

  • Theoretical investigation of atomic and electronic structures in inorganic functional materials

Charge of on-campus class subject

  • Materials and Industrial Engineering

    2021    

  • Materials Science and Engineering Laboratory III

    2021   Practical Training  

  • Advanced Computational Materials Science

    2021    

  • Materials Physics II

    2021    

Number of instructed thesis, researches

  • 2022

    Number of instructed the graduation thesis:Number of graduation thesis reviews:0

    [Number of instructed the Master's Program] (previous term):[Number of instructed the Master's Program] (letter term):0

    [Number of master's thesis reviews] (chief):[Number of master's thesis reviews] (vice-chief):4

    [Number of doctoral thesis reviews] (chief):[Number of doctoral thesis reviews] (vice-chief):0

Social Activities

  • その他公開講座 高校生のためのマテリアルサイエンス入門

    2021.04 - 2022.03

Visiting Lectures ⇒ Link to the list of Visiting Lectures

  • コンピューターで探るマテリアル

    Category:Science (mathematics, physics, chemistry, biology, geology, biochemistry), Engineering (machinery, electronics / physics, electrical / electronics, electrical information, chemical biotechnology, architecture, cities (civil engineering / environment), material chemistry, aerospace, marine systems, applied chemistry, chemistry, materials)

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    Audience:High school students, College students, Teachers, Researchers, General, Company, Civic organization

    Keyword:材料科学、量子力学、シミュレーション 

    私達の身の回りにある数多くの物質はさまざまな性質を示します。色の違い、電気を通すか通さないか、磁石に付くか付かないか。この様ありふれたな物質のもつ性質は、実は物質を構成する電子と原子核が物質の中どのように運動しているか、といったミクロな観点から初めて理解できます。
    本講義では、物質中の電子の運動を表わすことができる量子力学の発展と、コンピューターを利用して電子の運動をシミュレーションする方法について説明し、最先端の材料開発においてどの様に応用されているかを紹介します。

Academic Activities

  • Materials Transactions

    Role(s): Peer review

    The Japan Institute of Metals and Materials  2023.02 - 2023.03

  • Physical Review B

    Role(s): Peer review

    American Physical Society  2022.04

  • Chemical Physics Letters

    Role(s): Peer review

    Elsevier  2022.03 - 2022.05

  • Physical Review Letters

    Role(s): Peer review

    American Physical Society  2022.01

Original item・Special report (Social Activity)

  • 2022

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    Original item:内閣官房 グローバル・スタートアップ・キャンパス構想推進室 室員

    Special report:グローバル・スタートアップ・キャンパス構想の立ち上げに関わる業務を通じて、国内のスタートアップの促進とイノベーション強化に関わる政策に貢献。

  • 2022

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    Original item:内閣府 科学技術・イノベーション推進事務局 科学技術政策フェロー

    Special report:大学に関する国内外の動向を俯瞰して新たな価値を分析・創造する職務を通じ、科学技術政策の発展に寄与に貢献。

Other

  • 研究職歴

    2018.04 - 2021.03

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    大阪府立大学大学院工学研究科物質・化学系専攻マテリアル工学分野 (准教授)

  • 研究職歴

    2013.04 - 2018.03

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    大阪府立大学 21世紀科学研究機構 ナノ科学・材料研究センター