HIGASHI Tomohiro

写真a

Affiliation

Engineering educational research section Electrical and Electronic System Program 

Title

Associate Professor

Laboratory Address

工学部E棟204号室

Laboratory Phone number

0985-58-7353

Contact information

Contact information

Homepage

https://tmhgswx.miyazaki-u.ac.jp

External Link

Related SDGs


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Degree 【 display / non-display 】

  • 博士（工学） ( 2015.3   長崎大学 )

  • 修士（工学） ( 2012.3   長崎大学 )

  • 学士（工学） ( 2010.3   長崎大学 )

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Research Interests 【 display / non-display 】

  • Hydrogen

  • 光触媒

  • 分光電気化学

  • エネルギー変換

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Research Areas 【 display / non-display 】

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Catalyst and resource chemical process

  • Nanotechnology/Materials / Functional solid state chemistry

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Education 【 display / non-display 】

  • Nagasaki University

    2012.4 - 2015.3

  • Nagasaki University

    2010.4 - 2012.3

  • Nagasaki University

    2006.4 - 2010.3

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Campus Career 【 display / non-display 】

  • University of Miyazaki   Engineering educational research section   Electrical and Electronic System Program    Associate Professor

    2025.04 - Now

  • University of Miyazaki   Organization for Promotion of Research and Industry-Academic Regional Collaboration   Institute for Tenure Track Promotion   Assistant Professor

    2023.07 - 2025.03

  • University of Miyazaki   Organization for Promotion of Career Management   Institute for Tenure Track Promotion   Assistant Professor

    2021.11 - 2023.06

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External Career 【 display / non-display 】

  • The University of Tokyo   Department of Chemical System Engineering   Assistant Professor

    2017.4 - 2021.10

  • The University of Tokyo   Department of Chemical System Engineering   Researcher

    2015.4 - 2017.3

  • 日本学術振興会   日本学術振興会特別研究員

    2013.4 - 2015.3

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    Country：Japan

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Professional Memberships 【 display / non-display 】

  • 日本ポーラログラフ学会

  • 触媒学会

  • 電気化学会

  • 日本化学会

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Papers 【 display / non-display 】

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Books 【 display / non-display 】

  • 光触媒および光電極を用いた水分解反応によるソーラー水素製造

    東 智弘, 堂免 一成（ Role： Joint author）

    株式会社オプトロニクス社  2018 

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    Book type：Textbook, survey, introduction

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MISC 【 display / non-display 】

  • The 71st Annual Meeting of the Polarographic Society of Japan (PSJ)

    Higashi Tomohiro

    Review of Polarography   72 ( 1 )   31 - 34   2026.5

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    Authorship：Lead author   Language：Japanese   Publishing type：Meeting report   Publisher：The Polarographic Society of Japan  

    DOI： 10.5189/revpolarography.72.31

    CiNii Research

  • Electrochemical Identification of Surface States Limiting Overall Water Splitting in Particulate Oxynitride Photocatalysts Reviewed

    東 智弘

    ACS Energy Letters   11 ( 1 )   673 - 680   2025.12

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    Language：English   Publishing type：Rapid communication, short report, research note, etc. (scientific journal)   Publisher：ACS Publications  

    Oxynitride photocatalysts drive the hydrogen and oxygen evolution reactions under visible light with sacrificial reagents, but overall water splitting remains challenging, pointing to unresolved interfacial energetics. Here we integrate SrTaO2N and the (BaxSr1–x)TaO2N solid solution into particulate photoelectrodes and quantitatively probe their semiconductor properties at the solid/liquid interface. Beyond the rectifying behavior established for single-crystal photoelectrodes, electrochemical measurements using a reversible Fe3+/Fe2+ redox couple identify a defect-derived surface state located at 0.5 V vs the reversible hydrogen electrode in photocatalysts that mediates irreversible electron transfer. While this state enables half-reactions and rationalizes Z-scheme water splitting with suitable mediators, it promotes carrier recombination and thereby suppresses overall water splitting. This study establishes an electrochemical methodology that bridges photocatalyst powders and interfacial energetics and indicates that eliminating or passivating the defect states should enable overall pure water splitting in oxynitrides.

    CiNii Research

  • Estimating the quasi-Fermi level of holes at the surface of semiconductor photoanodes using outer-sphere redox couples Reviewed

    東 智弘

    Nature Communications   16 ( 1 )   3688   2025.4

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    Language：English   Publishing type：Rapid communication, short report, research note, etc. (scientific journal)   Publisher：Springer Science and Business Media LLC  

    Semiconductor electrodes can catalyze photo-induced redox reactions with light illumination. Photoexcitation produces excited carriers that subsequently transfer to the front and back contacts as determined by the bulk and surface properties of the photoelectrodes. This transfer defines the resultant quasi-Fermi levels of the photo-generated carriers at the photoelectrode surface, which, in turn, impacts the efficiency of surface photoelectrochemical reactions. However, determining such quasi-Fermi levels is not a simple task. In this study, we introduce a method for estimating the quasi-Fermi level of holes using outer-sphere electron transfer reactions. The quasi-Fermi level of holes is estimated by linking the oxidation photocurrent on photoanodes to the separately measured electrode potential on a stable metal electrode. Using this method, the quasi-Fermi level of holes at the surface is monitored in response to variations in applied potential and light intensity. This approach effectively separates the photocurrents of the CdS model electrode between surface redox reaction and photocorrosion, while concurrently quantifying the dynamic quasi-Fermi level at the surface. This work facilitates quantitative understanding of photoelectrochemical reactions on semiconductor electrodes to design green chemical transformation systems.

    CiNii Research

  • Maximizing Oxygen Evolution Performance of NiFeOx Semitransparent Electrocatalysts Applicable to Photoelectrochemical Water Splitting Device Reviewed

    東 智弘, 吉野 賢二

    ChemNanoMat   11 ( 1 )   e202400536   2025.1

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    Language：English   Publishing type：Rapid communication, short report, research note, etc. (scientific journal)   Publisher：Wiley  

    CiNii Research

  • Photoelectrochemical properties of p-type CuBi2O4 prepared by spray pyrolysis

    Wakishima Kaisei, Higashi Tomohiro, Nagaoka Akira, Yoshino Kenji

    53   75 - 78   2024.10

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    Language：Japanese   Publishing type：Rapid communication, short report, research note, etc. (bulletin of university, research institution)   Publisher：Faculty of Engineering, University of Miyazaki  

    DOI： 10.34481/0002000819

    CiNii Research

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Presentations 【 display / non-display 】

  • 半導体光電極/水溶液界面の設計による水分解特性の向上 Invited

    東 智弘

    第73回応用物理学会春季学術講演会  2026.3.15 

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    Event date： 2026.3.15 - 2026.3.18

    Language：Japanese   Presentation type：Oral presentation (invited, special)  

  • Enhanced Oxygen Evolution Performance of Semitransparent NiFeCoOx Thin-Film Cocatalysts for Photoelectrochemical Water Splitting International conference

    Koichi Yoshiyama, Tian Xiao, Kenji Yoshio, Tomohiro Higashi

    Materials Research Meeting (MRM) 2025  2025.12.10 

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    Event date： 2025.12.9 - 2025.12.12

    Language：English   Presentation type：Oral presentation (general)  

  • LaFeO3光電極のアニール温度の変化に伴う光電気化学特性の評価

    永峰 琢也, 麻生 裕介, 東 智弘

    第71回ポーラログラフィーおよび電気分析化学討論会  2025.10.22 

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    Event date： 2025.10.22 - 2025.10.23

    Presentation type：Poster presentation  

  • Interfacial Design of Semitransparent Photoelectrodes for Visible-Light-Driven Green Hydrogen Production Invited International conference

    Tomohiro Higashi

    2025 International G-LAMP Symposium on Renewable Energy Technologies  2025.8.28 

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    Event date： 2025.8.28 - 2025.8.29

    Language：English   Presentation type：Oral presentation (invited, special)  

  • Interfacial Engineering of Visible-Light-Absorbing Semitransparent Photoelectrodes for Durable Solar Water Splitting Invited International conference

    Tomohiro Higashi

    247th ECS Meeting  2025.5.18 

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    Event date： 2025.5.16 - 2025.5.21

    Language：English   Presentation type：Oral presentation (invited, special)  

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Awards 【 display / non-display 】

  • Best Presenter Award in APL Materials

    2023.9   Materials Oceania 2023  

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    Award type：Award from international society, conference, symposium, etc. 

  • President Award in Academic Excellence

    2015.3   Nagasaki University  

    Tomohiro Higashi

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Grant-in-Aid for Scientific Research 【 display / non-display 】

  • タンデム型水分解セルの長寿命化に向けた半透明な光電極への表面修飾法の開発

    Grant number：23K04917  2023.04 - 2027.03

    独立行政法人日本学術振興会  科学研究費基金  基盤研究(C)

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    Authorship：Principal investigator 

  • 光電極/水溶液界面で起こる水分解反応の精密電気化学測定

    Grant number：19K15670  2019.04 - 2022.03

    科学研究費補助金  若手研究

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    Authorship：Principal investigator 

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Committee Memberships 【 display / non-display 】

  • The Polarographic Society of Japan   Director of general affairs  

    2026.1   

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    Committee type：学協会

  • The Polarographic Society of Japan   Director of annual meeting  

    2025.1 - 2026.12   

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    Committee type：学協会

  • The Polarographic Society of Japan   Councilor  

    2023.1   

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    Committee type：学協会

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