各種時間分解振動分光を駆使した人工光合成過程のその場観測とメカニズムの解明

• Project Area: Creation of novel light energy conversion system through elucidation of the molecular mechanism of photosynthesis and its artificial design in terms of time and space
• Project/Area Number: 18H05170
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Research Institution: Kyushu University
• Principal Investigator: 恩田 健 九州大学, 理学研究院, 教授 (60272712)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000); Fiscal Year 2019: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000); Fiscal Year 2018: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
• Keywords: 時間分解振動分光 / 人工光合成 / 光化学 / 光触媒 / 錯体化学 / 時間分解赤外分光 / 反応ダイナミクス

Outline of Annual Research Achievements

本研究では、独自開発した時間分解振動分光装置により人工光合成過程を詳細に解析し、新規人工光合成系開発を促進することを目的とした。人工光合成過程は、光をエネルギー源とし、水を電子源、CO2を炭素源として高エネルギーな化学物質を得る過程である。この過程は多電子過程であるため必然的に、複雑な系で起こる多段階反応とならざるを得ない。そのような系に対し、本研究では実際の化学反応が起こる広い時間領域(ピコ秒からミリ秒)で、分子種やその状態を選択的に観測可能な時間分解振動分光を適用した。しかし従来型の装置ではこのような系の観測は困難であった。そこで、本新学術領域内で人工光合成過程を開発している多くのグループとの緊密な協力の下、実際の人工光合成過程を詳細に解析可能な装置開発を行った。さらに開発した装置を用い、人工光合成過程の理解に重要な以下の成果を得た。1. 超分子CO2光還元触媒における電子移動メカニズムの解明： 光増感部と触媒部からなる超分子錯体における錯体間電子移動がスルーボンド機構で起こることを明らかにし、その具体的な定数を求めることに成功した。2. 半導体-金属錯体複合体CO2光還元触媒における半導体から錯体への電子移動メカニズムの解明：半導体微粒子と錯体触媒を結合した複合体における半導体-錯体間電子移動が、エキサイプレックス状態と呼ばれる半導体と錯体の相互作用に生成した状態を経て、電子移動が起こることを明らかにした。3. 熱活性化遅延蛍光(TADF)物質におけるスピン変換過程の解明：分子の光励起状態におけるスピン返還過程が、励起状態構造変化に強く依存することを見出した。4. 各種機能性物質における光応答機構の解明：酸化グラフェン、シリコンナノドット、分子性半導体などの複雑系における光励起後の物理的、化学的過程の詳細を明らかにした。

Research Progress Status

令和元年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和元年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] Liquid-like dielectric response is an origin of long polaron lifetime exceeding 10 μ s in lead bromide perovskites (2020)
  • Author(s): Kiyoshi Miyata, Ryota Nagaoka, Masaki Hada, Takanori Tanaka, Ryuji Mishima, Taihei Kuroda, Sota Sueta, Takumi Iida, Yoshifumi Yamashita, Takeshi Nishikawa, Kenji Tsuruta, Yasuhiko Hayashi, Ken Onda, Toshihiko Kiwa, Takashi Teranishi
  • Journal Title: The Journal of Chemical Physics Volume: 152 Issue: 8 Pages: 084704-084704
  • DOI: 10.1063/1.5127993
  • Peer Reviewed
• [Journal Article] Selective Reduction Mechanism of Graphene Oxide Driven by the Photon Mode versus the Thermal Mode (2019)
  • Author(s): M. Hada, K. Miyata, S. Ohmura, Y. Arashida, K. Ichiyanagi, I. Katayama, T. Suzuki, W. Chen, S. Mizote, T. Sawa, T. Yokoya, T. Seki, J. Matsuo, T. Tokunaga, C. Itoh, K. Tsuruta, R. Fukaya, S. Nozawa, S. Adachi, J. Takeda, K. Onda, S. Koshihara, Y. Hayashi, Y. Nishina
  • Journal Title: ACS Nano Volume: 13 Issue: 9 Pages: 10103-10112
  • DOI: 10.1021/acsnano.9b03060
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Kinetics and Mechanism of Intramolecular Electron Transfer in Ru(II)?Re(I) Supramolecular CO2?Reduction Photocatalysts: Effects of Bridging Ligands (2019)
  • Author(s): Yamazaki Yasuomi、Ohkubo Kei、Saito Daiki、Yatsu Taiki、Tamaki Yusuke、Tanaka Sei’ichi、Koike Kazuhide、Onda Ken、Ishitani Osamu
  • Journal Title: Inorganic Chemistry Volume: 58 Issue: 17 Pages: 11480-11492
  • DOI: 10.1021/acs.inorgchem.9b01256
  • Peer Reviewed
• [Journal Article] Comparison of picosecond electron dynamics in isolated and clustered Si quantum dots deposited on a semiconductor surface (2019)
  • Author(s): K.Fukumoto, A.Seyhan, K.Onda, S.Oda, S.Koshihara
  • Journal Title: Applied Physics Letters Volume: 115 Issue: 5 Pages: 53105-53105
  • DOI: 10.1063/1.5097611
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Direct Measurement of Intramolecular Electron Transfer in a Series of Artificial Photosynthesis Processes (2019)
  • Author(s): Ken Onda, Kei Ohkubo, Yasuomi Yamazaki, Kazuhide Koike, Sei'ichi Tanaka, and Osamu Ishitani
  • Journal Title: Ultrafast Phenomena XXI, EPJ Web of Conf. Volume: 205 Pages: 09037-09037
  • DOI: 10.1051/epjconf/201920509037
  • Peer Reviewed
• [Journal Article] Suppression of Structural Change upon S1-T1 Conversion Assists the Thermally Activated Delayed Fluorescence Process in Carbazole-Benzonitrile Derivatives (2019)
  • Author(s): Saigo Masaki、Miyata Kiyoshi、Tanaka Sei’ichi、Nakanotani Hajime、Adachi Chihaya、Onda Ken
  • Journal Title: The Journal of Physical Chemistry Letters Volume: 10 Issue: 10 Pages: 2475-2480
  • DOI: 10.1021/acs.jpclett.9b00810
  • Peer Reviewed
• [Journal Article] Optical Study of Electronic Structure and Photoinduced Dynamics in the Organic Alloy System [(EDO-TTF)0.89(MeEDO-TTF)0.11]2PF6 (2019)
  • Author(s): T. Ishikawa, Y. Urasawa, T. Shindo, Y. Okimoto, S. Koshihara, S. Tanaka, K. Onda, T. Hiramatsu, Y. Nakano, K. Tanaka, H. Yamochi
  • Journal Title: Appl. Sci. Volume: 9 Issue: 6 Pages: 1174-1174
  • DOI: 10.3390/app9061174
  • Peer Reviewed / Open Access
• [Journal Article] Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals (2018)
  • Author(s): Masaki Hada, Shohei Saito, Ryuma Sato, Yasuhiko Hayashi, Yasuteru Shigeta, Ken Onda
  • Journal Title: Journal of Visualized Experiments Volume: 135 Issue: 135
  • DOI: 10.3791/57612
  • Peer Reviewed
• [Presentation] Analysis of Photofunctional Materials Using Time-resolved Infrared Spectroscopy (2020)
  • Author(s): Ken Onda
  • Organizer: New Trends in Photophysics of Photochemistry and their Applications - International Symposium between ETH Zurich and Kyushu University
  • Int'l Joint Research / Invited
• [Presentation] 時間分解赤外分光の基礎と光機能性材料開発への応用 (2019)
  • Author(s): 恩田健
  • Organizer: 光化学応用講座2019－時間分解分光の新展開：原理から先端応用まで－
  • Invited
• [Presentation] Principles and applications of time-resolved infrared spectroscopy (2019)
  • Author(s): Ken Onda
  • Organizer: XXIVth International Krutyn; Summer School 2019
  • Int'l Joint Research / Invited
• [Presentation] Time-resolved Infrared Spectroscopy for Exploring Photofunctions in Softcrystals (2019)
  • Author(s): Ken Onda
  • Organizer: The 2nd International Symposium of Soft Crystals
  • Int'l Joint Research / Invited
• [Presentation] Structural dynamics upon singlet-triplet conversion for developing efficient luminescent materials in organic light emitting diodes (2019)
  • Author(s): Ken Onda
  • Organizer: The 10th Shanghai-Tokyo Advanced Research Symposium on Ultrafast Intense Laser Science
  • Int'l Joint Research / Invited
• [Presentation] Structural Dynamics in TADF Materials Studied by Time-resolved Infrared Spectroscopy (2019)
  • Author(s): Ken Onda
  • Organizer: The 3rd Frontiers of Organic Semiconductor Lasers (FOSL)
  • Int'l Joint Research / Invited
• [Presentation] 時間分解赤外分光を用いた柔らかい分子結晶における光機能の解明 (2019)
  • Author(s): 恩田健
  • Organizer: 日本化学会 第99春季年会特別企画「機能性をもつ柔らかな分子結晶の新展開」
  • Invited
• [Presentation] Transition Metal Complexes in the Excited States Studied by Time-resolved Infrared Vibrational Spectroscopy (2018)
  • Author(s): K. Onda, M. Saigo, K. Miyata, T. Mukuta, S. Tanaka
  • Organizer: Post-ICCC2018 Conference in Fukuoka
  • Int'l Joint Research / Invited
• [Presentation] Realtime Observation of Photoenergy Conversion Processes using Metal Complexes (2018)
  • Author(s): K. Onda, M. Saigo, K. Miyata, T. Mukuta, S. Tanaka
  • Organizer: 43rd International Conference on Coordination Chemistry (ICCC2018)
  • Int'l Joint Research / Invited
• [Presentation] Structural Dynamics in Photofunctional Materials Studied by Time-resolved Infrared Spectroscopy (2018)
  • Author(s): Ken Onda
  • Organizer: International School and Symposium on Ultrafast Control of Materials (UCM2018)
  • Int'l Joint Research
• [Presentation] Structural Dynamics in Functional Materials Studied by Time-resolved Infrared Spectroscopy (2018)
  • Author(s): Ken Onda
  • Organizer: International symposium on spectroscopy and dynamics at surface and interface
  • Int'l Joint Research / Invited
• [Presentation] Structural Dynamics in Organic Light-Emitting Materials Studied by Time-resolved Infrared Spectroscopy (2018)
  • Author(s): Ken Onda
  • Organizer: Organic Optoelectronics: Lighting Up the Future A Scotland-Japan Symposium Jointly Organized
  • Int'l Joint Research / Invited
• [Presentation] Time-resolved Vibrational Spectroscopic Studies of Structural Dynamics in Photofunctional Materials (2018)
  • Author(s): Ken Onda
  • Organizer: Optics & Photonics International Congress 2018 (OPIC2018) / Conference on Laser and Synchrotron Radiation Combination Experiment (LSC2018)
  • Int'l Joint Research / Invited
• [Remarks] 九州大学理学研究院化学部門分光分析化学研究室
  • URL: http://www.scc.kyushu-u.ac.jp/Spectrochem/
• [Remarks] 業績リスト 恩田健
  • URL: http://www.scc.kyushu-u.ac.jp/Spectrochem/onda.html
• [Remarks] 九州大学分光分析化学研究室
  • URL: http://www.scc.kyushu-u.ac.jp/Spectrochem/
• [Remarks] 九州大学研究者情報 恩田健
  • URL: http://hyoka.ofc.kyushu-u.ac.jp/search/details/K006567/index.html