Takeshi Morikawa

A cooperating research team has begun efforts to accelerate the future implementation of artificial photosynthesis technologies in society. CO₂ reduction with a high efficiency of 7.2% has been demonstrated in a system with an electrode area approximately 1,000 times larger than the that of monolithic element. 

News Release Solar-Driven CO2 Recycling Technology! Dramatic Breakthrough in Artificial Photosynthesis

At present, we are also conducting research on technologies intended to realize high throughput CO₂ reduction for the synthesis of formic acid and carbon monoxide, and to demonstrate generation of molecules with chemical energy greater than them.

• Sakamoto, N., Sekizawa, K., Shirai, S., Nonaka, T., Arai, T., Sato, S. and Morikawa, T., “Dinuclear Cu(I) Molecular Electrocatalyst for CO₂-to-C₃ Product Conversion”, Nature Catalysis, Vol. 7, (2024), pp. 574-584.
  https://doi.org/10.1038/s41929-024-01147-y
   
• Kamada, K., Jung, J., Yamada, C., Wakabayashi, T., Sekizawa, K., Sato, S., Morikawa, T., Fukuzumi, S. and Saito, S., “Photocatalytic CO₂ Reduction Using an Osmium Complex as a Panchromatic Self-photosensitized Catalyst: Utilization of Blue, Green, and Red Light”, Angewandte Chemie-International Edition, Vol. 63, (2024), e202403886.
  https://doi.org/10.1002/anie.202403886

• Sato, S., Sekizawa, K., Shirai, S., Sakamoto, N. and Morikawa, T., “Enhanced Performance of Molecular Electrocatalysts for CO₂ Reduction in a flow Cell Following K⁺ Addition”, Science Advances, Vol. 9, (2023), eadh9986.
  https://doi.org/10.1126/sciadv.adh9986
   
• Suzuki, T. M., Nagatsuka, K., Nonaka, T., Yamaguchi, Y., Sakamoto, N., Uyama, T., Sekizawa, K., Kudo., A. and Morikawa, T., “Highly Selective CO₂ Electrolysis in Aqueous Media by a Water-soluble Cobalt Dimethyl-bipyridine Complex”, Chemical Communications, Vol. 59, (2023), pp. 12318-12321.
  https://doi.org/10.1039/d3cc03940d
   
• Bonchio, M., Bonin, J., Ishitani, O., Lu, T. B., Morikawa, T., Morris, A. J., Reisner E., Sarkar, D., Toma, F. M. and Robert, M., “Best Practices for Experiments and Reporting in Photocatalytic CO₂ Reduction”, Nature Catalysis, Vol. 6, (2023), pp. 657-665.
  https://doi.org/10.1038/s41929-023-00992-7
   
• Takeda, Y., Mizuno, S., Iwata, R., Morikawa, T. and Kato, N., “Gas-fed Liquid-covered Electrodes Used for Electrochemical Reduction of Dilute CO₂ in a Flue Gas”, Journal of CO2 Utilization, Vol. 71, (2023), 102472.
  https://doi.org/10.1016/j.jcou.2023.102472
   
• Takeda, Y., Yamanaka, K., Morikawa, T. and Kato, N., “Design Guides for Artificial Photosynthetic Devices Consisting of Voltage-matched Perovskite/Silicon Tandem Solar-cell Modules and Electrochemical Reactor Modules”, Japanese Journal of Applied Physics, Vol. 62, (2023), SK1018.
  https://doi.org/10.35848/1347-4065/acc3a5
   
• Takeda, Y., Sato, S. and Morikawa, T., “Effects of Impact Ionization and Auger Recombination on Hot-carrier Solar Cells and Hot-carrier Photocatalysts”, Japanese Journal of Applied Physics, Vol. 62, (2023), SK1003.
  https://doi.org/10.35848/1347-4065/acbebe
   
• Yamanaka, K., Sato, K., Sato, S., Nozawa, S., Lee, S., Fukaya, R., Fukuzawa, H., You, D., Saito, S., Takanashi, T., Katayama, T., Togashi, T., Nonaka, T., Dohmae, K., Adachi, S., Ueda, K., Yabashi, M., Morikawa, T. and Asahi, R., “Ultrafast Charge-transfer Dynamics in a Visible-light-excited Iridium(III) Terpyridine 2-phenylpyridine Complex Studied by Femtosecond X-ray Absorption Spectroscopy”, Journal of Photochemistry and Photobiology A: Chemistry, Vol. 435, (2023), 114267.
  https://doi.org/10.1016/j.jphotochem.2022.114267

• Takeda, Y., Yamanaka, K., Morikawa, T. and Kato, N., “Artificial Photosynthetic Monolithic Devices Using Voltage-matched Perovskite/Silicon Tandem Photovoltaic Modules”, Journal of Applied Physics, Vol. 132, (2022), 075002.
  https://doi.org/10.1063/5.0097485
   
• Kamada, K., Jung, J., Kametani, Y., Wakabayashi, T., Shiota, Y., Yoshizawa, K., Bae, S. H., Muraki, M., Naruto, M., Sekizawa, K., Sato, S., Morikawa, T. and Saito, S., “Importance of Steric Bulkiness of Iridium Photocatalysts with PNNP Tetradentate Ligands for CO₂ Reduction”, Chemical Communications, Vol. 58, (2022), pp. 9218-9221.
  https://doi.org/10.1039/d2cc01701f
   
• Ikeda, T., Suzuki, T. M., Arai, T. and Morikawa, T., “Ni-modified β-FeOOH Nanorod Cocatalysts for Oxygen Evolution Utilising Photoexcited Holes on a N 2p Level in a N-doped TiO₂ Electrode”, Chemical Communications, Vol. 58, (2022), pp. 8125-8128.
  https://doi.org/10.1039/d2cc02795j
   
• Suzuki, T. M., Yoshino, S., Sekizawa, K., Yamaguchi, Y., Kudo, A. and Morikawa, T., “Photocatalytic CO₂ Reduction by a Z-scheme Mechanism in an Aqueous Suspension of Particulate (CuGa)_0.3Zn_1.4S₂, BiVO₄ and a Co Complex Operating Dual-functionally as an Electron Mediator and as a Cocatalyst”, Applied Catalysis B-Environmental, Vol. 316, (2022), 121600.
  https://doi.org/10.1016/j.apcatb.2022.121600
   
• Wakabayashi, T., Kamada, K., Sekizawa, K., Sato, S., Morikawa, T., Jung, J. and Saito, S., “Photocatalytic CO₂ Reduction Using an Iron-Bipyridyl Complex Supported by Two Phosphines for Improving Catalyst Durability”, Organometallics, Vol. 41, (2022), pp. 1865-1871
  https://doi.org/10.1021/acs.organomet.2c00171
   
• Takeda, Y., Sato, S. and Morikawa, T., “Hot-carrier Photocatalysts for Artificial Photosynthesis”, Journal of Chemical Physics, Vol. 156, (2022), 164705.
  https://doi.org/10.1063/5.0088459
   
• Yoshino, S., Iwase, A., Yamaguchi, Y., Suzuki, T. M., Morikawa, T. and Kudo, A., “Photocatalytic CO₂ Reduction Using Water as an Electron Donor under Visible Light Irradiation by Z-Scheme and Photoelectrochemical Systems over (CuGa)_0.5ZnS₂ in the Presence of Basic Additives”, Journal of the American Chemical Society, 144, (2022), pp. 2323-2332.
  https://doi.org/10.1021/jacs.1c12636
   
• Morikawa, T., Sato, S., Sekizawa, K., Suzuki, T. M. and Arai, T., “Solar-driven CO₂ Reduction Using a Semiconductor/Molecule Hybrid Photosystem: from Photocatalysts to a Monolithic Artificial Leaf”, Accounts of Chemical Research, Vol. 55, (2022), pp. 933-943.
  https://doi.org/10.1021/acs.accounts.1c00564
   
• Kamada, K., Okuwa, H., Wakabayashi, T., Sekizawa, K., Sato, S., Morikawa, T., Jung, J. and Saito, S., “A Highly Durable, Self-photosensitized Mononuclear Ruthenium Catalyst for CO₂ Reduction”, Synlett, Vol. 33, (2022), pp. 1137-1141.
  https://doi.org/10.1055/a-1709-0280
   

< Related Article >

• “A new leaf unfolds in artificial photosynthesis”
  https://www.nature.com/articles/d42473-021-00577-7

• Kato, N., Takeda, Y., Kawai, Y., Nojiri, N., Shiozawa, M., Mizuno, S., Yamanaka, K., Morikawa, T. and Hamaguchi, T., “Solar Fuel Production from CO₂ Using a 1 m-Square-Sized Reactor with a Solar-to-formate Conversion Efficiency of 10.5%”, ACS Sustainable Chemistry & Engineering, Vol. 9, (2021), pp. 16031-16037.
  https://doi.org/10.1021/acssuschemeng.1c06390
   
• Sakamoto, N., Sekizawa, K., Sato, S., Ohashi, M., Nonaka, T., Nishimura, Y. F., Kitazumi K., Morikawa, T. and Arai, T., “Electrochemical CO₂ Reduction Improved by Tuning the Cu-Cu Distance in Halogen-bridged Dinuclear Cuprous Coordination Polymers”, Journal of Catalysis, Vol. 404, (2021), pp. 12-17.
  https://doi.org/10.1016/j.jcat.2021.09.013
   
• Nishi, T., Sato, S. and Morikawa, T., “Electrochemical CO₂ Reduction to HCOOH Catalyzed by Ag_n(NO₃) _n+1 Clusters Prepared by Laser Ablation at the Air-Liquid Interface”, Chemistry Letters, Vol. 50, (2021), pp. 1941-1944.
  https://doi.org/10.1246/cl.210483
   
• Takeda, Y., Suzuki, T. M., Sato, S. and Morikawa, T., “Particulate Photocatalytic Reactors with Spectrum-splitting Function for Artificial Photosynthesis”, Physical Chemistry Chemical Physics, Vol. 23, (2021), pp. 15659-15674.
  https://doi.org/10.1039/d1cp00597a
   
• Nishi, T., Sato, S., Sekizawa, K., Suzuki, T. M., Oh-ishi, K., Takahashi, N., Matsuoka, Y. and Morikawa, T., “Carbon Nanohorn Support for Solar Driven CO₂ Reduction to CO Catalyzed by Mn-complex in an All Earth-abundant System”, ChemNanoMat, Vol. 7, (2021), pp. 596-599.
  https://doi.org/10.1002/cnma.202100081
   
• Kato, N., Mizuno, S., Shiozawa, M., Nojiri, N., Kawai, Y., Fukumoto, K., Morikawa, T. and Takeda, Y., “A Large-sized Cell for Solar-driven CO₂ Conversion with a Solar-to-formate Conversion Efficiency of 7.2%”, Joule, Vol. 5, (2021), pp.1-19.
  https://doi.org/10.1016/j.joule.2021.01.002

• Suzuki, T.M., Ishizaki, T., Kosaka, S., Takahashi, N., Isomura, N., Seki, J., Matsuoka, Y., Oh-ishi, K., Oshima, A., Kitazumi, K., Sekizawa, K. and Morikawa, T., “Electrochemical CO₂ Reduction Over Nanoparticles Derived from an Oxidized Cu–Ni Intermetallic Alloy”, Chemical Communications, Vol.56, (2020), pp.15008-15011.
  https://doi.org/10.1039/D0CC06130A
   
• Sato, S., Tanaka, S., Yamanaka, K. I., Saeki, S., Sekizawa, K., Suzuki, T.M., Morikawa, T. and Onda, K., “Study of Excited States and Electron Transfer of Semiconductor‐metal-complex Hybrid Photocatalysts for CO₂ Reduction by Using Picosecond Time-resolved Spectroscopies”, Chemistry – A European Journal, Vol.27, (2020) , pp. 1127-1137.
  https://doi.org/10.1002/chem.202004068
   
• Sato, K., Yamanaka, K. I., Nozawa, S., Fukuzawa, H., Katayama, T., Morikawa, T., Nonaka, T., Dohmae, K., Ueda, K., Yabashi, M. and Asahi, R., “Charge Trapping Process in Photoexcited Nitrogen-doped Titanium Oxides”, Inorganic Chemistry, Vol.59, (2020) , pp.10439-10449.
  https://doi.org/10.1021/acs.inorgchem.0c00696
   
• Sakamoto, N., Nishimura, F.Y., Nonaka, T., Ohashi, M., Ishida, N., Kitazumi, K., Kato, Y., Sekizawa, K., Morikawa, T. and Arai, T., “Self-assembled Cuprous Coordination Polymer as a Catalyst for CO₂ Electrochemical Reduction into C2 Products”, ACS Catalysis, Vol. 10, (2020), pp.10412-10419.
  https://doi.org/10.1021/acscatal.0c01593
   
• Mukai, K., Suzuki, T.M., Uyama, T., Nonaka, T., Morikawa, T. and Yamada, I., “High-pressure Synthesis of ε-FeOOH from β-FeOOH and Its Application to the Water Oxidation Catalyst”, RSC Advances Vol. 10, (2020) pp.44756-44767.
  https://doi.org/10.1039/D0RA09895G
   
• Kamada, K., Jung, J., Wakabayashi, T., Sekizawa, K., Sato, S., Morikawa, T., Fukuzumi, S. and Saito, S., “Photocatalytic CO₂ Reduction Using a Robust Multifunctional Iridium Complex towards the Selective Formation of Formic Acid”, Journal of the American Chemical Society, Vol. 142, No. 23 (2020), pp. 10261-10266.
  https://doi.org/10.1021/jacs.0c03097
   
• Takeda, Y., Morikawa, T. and Kato, N., “Spectrally Robust Series/parallel-connected Triple-junction Photovoltaic Cells Used for Artificial Photosynthesis”, Journal of Applied Physics, Vol. 127, No. 20 (2020), 204503.
  https://doi.org/10.1063/5.0006310
   
• Nishi, T., Sato, S., Ohshima, A., Nakamura, T., Sato, S. and Morikawa, T., “Formation of C2 Organic Molecules From CO₂ and H₂O by Femtosecond Laser Induced Chemical Reactions in Water”, Japanese Journal of Applied Physics, Vol. 59, No. 5 (2020), 057001.
  https://doi.org/10.35848/1347-4065/ab87de
   
• Morikawa, T., Gul, S., Nishimura, Y.F., Suzuki, T.M. and Yano, J., ”Operando X-ray Absorption Spectroscopy of Hyperfine β-FeOOH Nanorods Modified with Amorphous Ni(OH)₂ under Electrocatalytic Water Oxidation Conditions”, Chemical Communications, Vol. 56 (2020), pp. 5158-5161.
  https://doi.org/10.1039/D0CC00692K
   
• Sekizawa, K., Oh-ishi, K. and Morikawa, T., “Photoelectrochemical Water-splitting over a Surface Modified p-type Cr₂O₃ Photocathode”, Dalton Transactions, Vol. 49 (2020), pp. 659-666.
  https://doi.org/10.1039/C9DT04296B

• Morikawa, T., Sato, S., Sekizawa, K., Arai, T. and Suzuki, T. M., "Molecular Catalysts Immobilized on Semiconductor Photosensitizers for Proton Reduction toward Visible-light-driven Overall Water Splitting", ChemSusChem, Vol. 12, No. 9 (2019), pp. 1807-1824.
  https://doi.org/10.1002/cssc.201900441
   
• Sakamoto, Y., Noda, Y., Ohno, K., Koike, K., Fujii, K., Suzuki, T. M., Morikawa, T. and Nakamura, S., "First Principles Calculations of Surface Dependent Electronic Structures: a Study on β-FeOOH and γ-FeOOH", Physical Chemistry Chemical Physics, Vol. 21 (2019), pp. 18486-18494.
  https://doi.org/10.1039/C9CP00157C
   
• Kimura, T., Sato, S., Kataoka, K., Morikawa, T. and Nakamura, D., "Self-assembled Single-crystalline GaN Having a Bimodal Meso/Macropore Structure to Enhance Photoabsorption and Photocatalytic Reactions", ACS Applied Materials & Interfaces, Vol. 11, No. 4 (2019), pp. 4233-4241.
  https://doi.org/10.1021/acsami.8b18088
   
• Arai, T., Sato, S., Sekizawa, K., Suzuki, T. M. and Morikawa, T., “Solar-driven CO₂ to CO Reduction Utilizing H₂O as an Electron Donor by Earth-abundant Mn-bipyridine Complex and Ni-modified Fe-oxyhydroxide Catalysts Activated in a Single-compartment Reactor”, Chemical Communications, Vol. 55 (2019), pp. 237-240.
  https://doi.org/10.1039/c8cc07900e

• Sato, S., Saita, K., Sekizawa, K., Maeda, S. and Morikawa, T., “Low-energy Electrocatalytic CO₂ Reduction in Water over Mn-complex Catalyst Electrode Aided by a Nanocarbon Support and K⁺ Cations”, ACS Catalysis, Vol. 8 (2018), pp. 4452-4458.
  https://doi.org/10.1021/acscatal.8b01068
   
• Suzuki, T. M., Yoshino, S., Takayama, T., Iwase, A., Kudo, A. and Morikawa, T., “Z-schematic and Visible-light-driven CO₂ Reduction Using H₂O as an Electron Donor by a Particulate Mixture of a Ru-complex/(CuGa)_1−xZn_2xS₂ Hybrid Catalyst, BiVO₄ and an Electron Mediator”, Chemical Communications, Vol. 54 (2018), pp. 10199-10202.
  https://doi.org/10.1039/C8CC05505J
   
• Nishi, T., Hayasaka, Y., Nakamura, T., Morikawa, T. and Sato, S., “Core-shell Like Au-Ir Nanoparticles with Spatially Variant Electronic State of Au Synthesized by Femtosecond Laser Irradiation of Solution”, Applied Surface Science, Vol. 457, No. 1 (2018), pp. 1044-1049.
  https://doi.org/10.1016/j.apsusc.2018.07.046
   
• Sato, S., Kataoka, K., Jinnouchi, R., Takahashi, N., Sekizawa, K., Kitazumi, K., Ikenaga, E., Asahi, R. and Morikawa, T., “Band Bending and Dipole Effect at Interface of Metal-nanoparticles and TiO₂ Directly Observed by Angular-resolved Hard X-ray Photoemission Spectroscopy”, Physical Chemistry Chemical Physics, Vol. 20 (2018), pp. 11342-11346.
  https://doi.org/10.1039/C8CP00551F
   
• Nishi, T., Hayasaka, Y., Suzuki, T. M., Sato, S., Isomura, N., Takahashi, N., Kosaka, S., Nakamura, T., Sato, S. and Morikawa, T., “Electrochemical Water Oxidation Catalysed by CoO‐Co₂O₃‐Co(OH)₂ Multiphase‐nanoparticles Prepared by Femtosecond Laser Ablation in Water”, ChemistrySelect, Vol. 3, No. 17 (2018), pp. 4979-4984.
  https://doi.org/10.1002/slct.201800943
   
• Sekizawa, K., Sato, S., Arai, T. and Morikawa, T., "Solar-driven Photocatalytic CO₂ Reduction in Water Utilizing a Ruthenium Complex Catalyst on p-Type Fe₂O₃ with a Multiheterojunction", ACS Catalysis, Vol. 8, No. 2 (2018), pp. 1405-1416. http://dx.doi.org/10.1021/acscatal.7b03244
   
• Shirai, S., Sato, S., Suzuki, T. M., Jinnouchi, R., Ohba, N., Asahi, R. and Morikawa, T., “Effects of Ta₂O₅ Surface Modification by NH₃ on the Electronic Structure of a Ru-Complex/N–Ta₂O₅ Hybrid Photocatalyst for Selective CO₂ Reduction”, Journal of Physical Chemistry C, Vol. 122 (2018), pp. 1921-1929. http://dx.doi.org/10.1021/acs.jpcc.7b09670
   
• Suzuki, T. M., Takayama, T., Sato, S., Iwase, A., Kudo, A. and Morikawa, T., “Enhancement of CO₂ Reduction Activity under Visible Light Irradiation over Zn-based Metal Sulfides by Combination with Ru-complex Catalysts”, Applied Catalysis B: Environmental, Vol. 224 (2018), pp. 572-578. https://doi.org/10.1016/j.apcatb.2017.10.053
   
• Suzuki, T. M., Nonaka, T., Kitazumi, K., Takahashi, N., Kosaka, S., Matsuoka, Y., Sekizawa, K., Suda, A. and Morikawa, T., “Highly Enhanced Electrochemical Water Oxidation Reaction over Hyperfine β-FeOOH(Cl): Ni Nanorod Electrode by Modification with Amorphous Ni(OH)₂”, Bulletin of Chemical Society of Japan, Vol. 91, No. 5 (2018), pp. 778-786. https://doi.org/10.1246/bcsj.20170426
   
• Sato, S. and Morikawa, T., “[Ir(tpy)(bpy)Cl] as a Photocatalyst for CO₂ Reduction under Visible-light Irradiation”, ChemPhotoChem, Vol. 2 (2018), pp. 207-212. http://dx.doi.org/10.1002/cptc.201700133
   
• Sato, S., Arai, T. and Morikawa, T., “Electrocatalytic CO₂ Reduction Near the Theoretical Potential in Water Using Ru Complex Supported on Carbon Nanotubes”, Nanotechnology, Vol. 29, No. 3 (2018), 034001. https://doi.org/10.1088/1361-6528/aa9d50
   
• Yoshida, H., Sato, M., Fukuo, N., Zhang, L., Yoshida, T., Yamamoto, Y., Morikawa, T., Kajino, T., Sakano, M., Sekito, T., Matsumoto, S. and Hirata, H., “Sodium Hexatitanate Photocatalysts Prepared by a Flux Method for Reduction of Carbon Dioxide with Water”, Catalysis Today, Vol. 303 (2018), pp. 296-304. https://doi.org/10.1016/j.cattod.2017.09.029

• Suzuki, T. M., Saeki, S., Sekizawa, K., Kitazumi, K., Takahashi, N. and Morikawa, T., “Photoelectrochemical Hydrogen Production by Water Splitting over Dual-functionally Modified Oxide: p-Type N-doped Ta₂O₅ Photocathode Active under Visible Light Irradiation”, Applied Catalysis B: Environmental, Vol. 202 (2017), pp. 597-604. https://doi.org/10.1016/j.apcatb.2016.09.066
   
• Suzuki, T. M., Nonaka, T., Suda, A., Suzuki, N., Matsuoka, Y., Arai, T., Sato, S. and Morikawa, T., “Highly Crystalline β-FeOOH(Cl) Nanorod Catalysts Doped with Transition Metals for Efficient Water Oxidation”, Sustainable Energy & Fuels, Vol. 1, No. 3 (2017), pp. 636-643. https://doi.org/10.1039/C7SE00043J
   
• Sekizawa, K., Oh-ishi, K., Kataoka, K., Arai, T., Suzuki, T. M. and Morikawa, T., "Stoichiometric Water Splitting using a p-type Fe₂O₃ Based Photocathode with the Aid of a Multi-heterojunction", Journal of Materials Chemistry A, Vol. 5, No. 14 (2017), pp. 6483-6493. http://dx.doi.org/10.1039/C7TA00431A
   

< Related Paper >

• Morikawa, T., Sato, S. and Arai, T., “Chapter 7: Light-driven Carbon Dioxide Reduction Devices”, Molecular Devices for Solar Energy Conversion and Storage, Ed. by Tian, H., Boschloo, G. and Hagfeldt, A. (2017), pp. 259-280, Springer International Publishing. https://doi.org/10.1007/978-981-10-5924-7_7

• Arai, T., Sato, S. and Morikawa, T., “Aminoalkylsilane-modified Silver Cathodes for Electrochemical CO₂ Reduction”, Chemistry Letters, Vol. 45 (2016), pp. 1362-1364. https://doi.org/10.1246/cl.160685
   
• Sato, S. Arai, T. and Morikawa, T., “Carbon Microfiber Layer as Noble Metal-catalyst Support for Selective CO₂ Photoconversion in Phosphate Solution: Toward Artificial Photosynthesis in a Single-compartment Reactor”, Journal of Photochemistry and Photobiology A -Chemistry, Vol. 327, No. 1 (2016), pp. 1-5. https://doi.org/10.1016/j.jphotochem.2016.04.017
   
• Ohwaki, T. Saeki, S. Aoki, K. and Morikawa, T., “Evaluation of Photocatalytic Activities and Characteristics of Cu- or Fe-modified Nitrogen-doped Titanium Dioxides for Applications in Environmental Purification”, Japanese Journal of Applied Physics, Vol.55, No. 1 (2016), pp. 01AA05. http://doi.org/10.7567/JJAP.55.01AA05
   

< Related Paper  >

• Morikawa, T., “CO₂ Reduction by Photoelectrochemistry”, Solar to Chemical Energy Conversion　Ed. by Sugiyama, M., Fujii, K. and Nakamura, S. (2016), pp. 281-296, Springer International Publishing, Switzerland.

• Arai, T., Sato, S. and Morikawa, T., "A Monolithic Device for CO₂ Photoreduction to Generate Liquid Organic Substances in a Single-compartment Reactor", Energy & Environmental Science, Vol. 8, No. 7 (2015), pp. 1998-2002. http://dx.doi.org/10.1039/c5ee01314c
   
• Yoshida, H., Zhang, L.K., Sato, M., Morikawa, T., Kajino, T., Sekito, T., Matsumoto, S. and Hirata, H., "Calcium Titanate Photocatalyst Prepared by a Flux Method for Reduction of Carbon Dioxide with Water", Catalysis Today, Vol. 251 (2015), pp. 132-139. http://dx.doi.org/10.1016/j.cattod.2014.10.039
   
• Sato, S., Arai, T. and Morikawa, T., "Toward Solar-driven Photocatalytic CO₂ Reduction Using Water as an Electron Donor", Inorganic Chemistry, Vol. 54, No. 11 (2015), pp. 5105-5113. http://dx.doi.org/10.1021/ic502766g
   
• Sahara, G., Abe, R., Higashi, M., Morikawa, T., Maeda, K., Ueda, Y. and Ishitani, O., "Photoelectrochemical CO₂ Reduction Using a Ru(II)-Re(I) Multinuclear Metal Complex on a p-type Semiconducting NiO Electrode", Chemical Communications, Vol. 51, No. 53 (2015), pp. 10722-10725. http://dx.doi.org/10.1039/c5cc02403j
   
• Suzuki, T. M., Iwase, A., Tanaka, H., Sato, S., Kudo, A. and Morikawa, T., "Z-scheme Water Splitting under Visible Light Irradiation over Powdered Metal-complex/semiconductor Hybrid Photocatalysts Mediated by Reduced Graphene Oxide", Journal of Materials Chemistry A, Vol. 3, No. 25 (2015), pp. 13283-13290. http://dx.doi.org/10.1039/c5ta02045j
   

< Related Papers  >

• Garg, K., Matsubara, Y., Ertem, M. Z., Lewandowska-Andralojc, A., Sato, S., Szalda, D. J., Muckerman, J. T. and Fujita, E., "Striking Differences in Properties of Geometric Isomers of [Ir(tpy)(ppy)H]+ : Experimental and Computational Studies of their Hydricities, Interaction with CO₂ , and Photochemistry", Angewandte Chemie International Edition Paper, in press. http://dx.doi.org/10.1002/anie.201506961
   
• Akimov, A. V., Asahi, R., Jinnouchi, R. and Prezhdo, O. V., "What Makes the Photocatalytic CO₂ Reduction on N-Doped Ta₂O₅ Efficient: Insights from Nonadiabatic Molecular Dynamics", Journal of the American Chemical Society, Vol. 137, No. 35(2015), pp. 11517-11525. http://dx.doi.org/10.1021/jacs.5b07454

• Asahi, R., Morikawa, T., Irie, H. and Ohwaki, T., "Nitrogen-Doped Titanium Dioxide as Visible-Light-Sensitive Photocatalyst: Designs, Developments, and Prospects", Chemical Reviews, Vol. 114, No. 19 (2014), pp. 9824-9852. http://dx.doi.org/10.1021/cr5000738
   
• Sekizawa, K., Nonaka, T., Arai, T. and Morikawa, T., "Structural Improvement of CaFe₂O₄ by Metal Doping toward Enhanced Cathodic Photocurrent", Acs Applied Materials & Interfaces, Vol. 6, No. 14 (2014), pp. 10969-10973. http://dx.doi.org/10.1021/am502500y
   
• Suzuki, T. M., Kitahara, G., Arai, T., Matsuoka, Y. and Morikawa, T., "Nitrogen and Transition-metal Codoped Titania Nanotube Arrays for Visible-light-sensitive Photoelectrochemical Water Oxidation", Chemical Communications, Vol. 50, No. 57 (2014), pp. 7614-7616. http://dx.doi.org/10.1039/c4cc02571g
   

< Related Papers >

• Akimov, A. V., Jinnouchi, R., Shirai, S., Asahi, R. and Prezhdo O. V., " Theoretical Insights into the Impact of Ru Catalyst Anchors on the Efficiency of Photocatalytic CO₂ Reduction on Ta₂O₅", Journal of Physical Chemistry B, Vol. 119, No. 24(2014), pp.7186-7197. http://dx.doi.org/10.1021/jp5080658

• Yamanaka, K., Ohwaki, T. and Morikawa, T., "Charge-carrier Dynamics in Cu- or Fe-loaded Nitrogen-doped TiO₂ Powder Studied by Femtosecond Diffuse Reflectance Spectroscopy", Journal of Physical Chemistry C, Vol. 117, No. 32 (2013), pp. 16448-16456. http://dx.doi.org/10.1021/jp404431z
   
• Morikawa, T., Arai, T. and Motohiro, T., "Photoactivity of p-Type alpha-Fe₂O₃ Induced by Anionic/Cationic Codoping of N and Zn", Applied Physics Express, Vol. 6, No. 4 (2013). http://dx.doi.org/10.7567/APEX.6.041201
   
• Arai, T., Sato, S., Kajino, T. and Morikawa, T., "Solar CO₂ Reduction Using H₂O by a Semiconductor/metal-complex Hybrid Photocatalyst: Enhanced Efficiency and Demonstration of a Wireless System Using SrTiO₃ Photoanodes", Energy & Environmental Science, Vol. 6, No. 4 (2013), pp. 1274-1282. http://dx.doi.org/10.1039/c3ee24317f
   
• Morikawa, T., Sato, S., Arai, T., Uemura, K., Yamanaka, K.I., Suzuki, T. M., Kajino, T. and Motohiro, T., "Selective CO₂ Reduction Conjugated with H₂O Oxidation Utilizing Semiconductor/Metal-Complex Hybrid Photocatalysts", Solar Chemical Energy Storage (Solches), Vol. 1568 (2013), pp. 11-15. http://dx.doi.org/10.1063/1.4848080
   
• Sato, S., Morikawa, T., Kajino, T. and Ishitani, O., "A Highly Efficient Mononuclear Iridium Complex Photocatalyst for CO₂ Reduction under Visible Light", Angewandte Chemie-International Edition, Vol. 52, No. 3 (2013), pp. 988-992. http://dx.doi.org/10.1002/anie.201206137
   
• Suzuki, T. M., Nakamura, T., Saeki, S., Matsuoka, Y., Tanaka, H., Sato, S., Yano, K., Kajino, T. and Morikawa, T., "Novel Hybrid Photocatalyst for Visible-light-sensitive CO₂ Reduction; Direct Assembly Synthesis of a Metal-complex on Spherical Mesoporous Semiconductor", R&D Rev. Toyota CRDL, Vol. 44, No. 3, pp. 63-72.

• Yamanaka, K and Morikawa, T., "Charge-carrier Dynamics in Nitrogen-Doped TiO₂ Powder Studied by Femtosecond Time-Resolved Diffuse Reflectance Spectroscopy", Journal of Physical Chemistry C, Vol. 116, No. 1 (2012), pp. 1286-1292. http://dx.doi.org/10.1021/jp209210u
   
• Suzuki, T. M., Nakamura, T., Saeki, S., Matsuoka, Y., Tanaka, H., Yano, K., Kajino, T. and Morikawa, T., "Visible Light-sensitive Mesoporous N-doped Ta₂O₅ Spheres: Synthesis and Photocatalytic Activity for Hydrogen Evolution and CO₂ Reduction", Journal of Materials Chemistry, Vol. 22, No. 47 (2012), pp. 24584-24590. http://dx.doi.org/10.1039/c2jm33980c
   
• Kajino, T., Morikawa, T., Sato, S., Arai, T., Suzuki,T. M., Uemura, K., Yamanaka, K., Saeki, S. and Tanaka, H., “Direct Synthesis of Organic Compounds from CO₂, Water and Sunlight”, R&D Rev. Toyota CRDL, Vol. 43, No. 2, pp. 43-52.

• Sato, S., Arai, T., Morikawa, T., Uemura, K., Suzuki, T. M., Tanaka, H. and Kajino, T., "Selective CO₂ Conversion to Formate Conjugated with H₂O Oxidation Utilizing Semiconductor/Complex Hybrid Photocatalysts", Journal of the American Chemical Society, Vol. 133, No. 39 (2011), pp. 15240-15243. http://dx.doi.org/10.1021/ja204881d
   
• Yamanaka, K., Sato, S., Iwaki, M., Kajino, T. and Morikawa, T., "Photoinduced Electron Transfer from Nitrogen-Doped Tantalum Oxide to Adsorbed Ruthenium Complex", Journal of Physical Chemistry C, Vol. 115, No. 37 (2011), pp. 18348-18353. http://dx.doi.org/10.1021/jp205223k
   
• Morikawa, T., Kitazumi, K., Takahashi, N., Arai, T. and Kajino, T., "p-type Conduction Induced by N-doping in alpha-Fe₂O₃", Applied Physics Letters, Vol. 98, No. 24 (2011), 242108. http://dx.doi.org/10.1063/1.3599852
   
• Suzuki, T. M., Tanaka, H., Morikawa, T., Iwaki, M., Sato, S., Saeki, S., Inoue, M., Kajino, T. and Motohiro, T., "Direct Assembly Synthesis of Metal Complex-semiconductor Hybrid Photocatalysts Anchored by Phosphonate for Highly Efficient CO₂ Reduction", Chemical Communications, Vol. 47, No. 30 (2011), pp. 8673-8675. http://dx.doi.org/10.1039/c1cc12491a
   
• Arai, T., Tajima, S., Sato, S., Uemura, K., Morikawa, T. and Kajino, T., "Selective CO₂ Conversion to Formate in water Using a CZTS Photocathode Modified with a Ruthenium Complex Polymer", Chemical Communications, Vol. 47, No. 47 (2011), pp. 12664-12666. http://dx.doi.org/10.1039/c1cc16160a
   
• Morikawa, T., Suzuki, K., Masaki, H., Ito, T., Kitazumi, K., Takahashi, N., Aoki, K., Asahi, R. and Ohwaki T., “Enhanced Visible-light Photocatalysis over N-doped TiO2 by Loading with Fe, Cu, or Pt Cocatalysts”, R&D Rev. Toyota CRDL, Vol. 42, No. 2, pp. 47-53.

• Katoh, R., Furube, A., Yamanaka, K. and Morikawa, T., "Charge Separation and Trapping in N-Doped TiO₂ Photocatalysts: A Time-resolved Microwave Conductivity Study", Journal of Physical Chemistry Letters, Vol. 1, No. 22 (2010), pp. 3261-3265. http://dx.doi.org/10.1021/jz1011548
   
• Arai, T., Sato, S., Uemura, K., Morikawa, T., Kajino, T. and Motohiro, T., "Photoelectrochemical Reduction of CO₂ in Water under Visible-light Irradiation by a p-type InP Photocathode Modified with an Electropolymerized Ruthenium Complex", Chemical Communications, Vol. 46, No. 37 (2010), pp. 6944-6946. http://dx.doi.org/10.1039/c0cc02061c
   
• Sugiyama, Y., Okamoto, H., Mitsuoka, T., Morikawa, T., Nakanishi, K., Ohta, T. and Nakano, H., "Synthesis and Optical Properties of Monolayer Organosilicon Nanosheets", Journal of the American Chemical Society, Vol. 132, No. 17 (2010), pp. 5946-5947. http://dx.doi.org/10.1021/ja100919d
   
• Morikawa, T., Saeki, S., Suzuki, T., Kajino, T. and Motohiro, T., "Dual Functional Modification by N Doping of Ta₂O₅: p-type Conduction in Visible-light-activated N-doped Ta₂O₅", Applied Physics Letters, Vol. 96, No. 14 (2010), 14211. http://dx.doi.org/10.1063/1.3386532
   
• Sato, S., Morikawa, T., Saeki, S., Kajino, T. and Motohiro, T., "Visible-light-induced Selective CO₂ Reduction Utilizing a Ruthenium Complex Electrocatalyst Linked to a p-Type Nitrogen-Doped Ta₂O₅ Semiconductor", Angewandte Chemie-International Edition, Vol. 49, No. 30 (2010), pp. 5101-5105. http://dx.doi.org/10.1002/anie.201000613

• Yoshinaga, M., Yamamoto, K., Sato, N., Aoki, K., Morikawa, T. and Muramatsu, A., "Remarkably Enhanced Photocatalytic Activity by Nickel Nanoparticle Deposition on Sulfur-doped Titanium Dioxide Thin Film", Applied Catalysis B-Environmental, Vol. 87, No. 3/4 (2009), pp. 239-244. http://dx.doi.org/10.1016/j.apcatb.2008.08.023
   
• Nakano, Y., Saeki, S. and Morikawa, T., "Optical Bandgap Widening of p-type Cu₂O Films by Nitrogen Doping", Applied Physics Letters, Vol. 94, No. 2 (2009), 02211. http://dx.doi.org/10.1063/1.3072804

• Morikawa, T., Ohwaki, T., Suzuki, K.I., Moribe, S. and Tero-Kubota, S., "Visible-light-induced Photocatalytic Oxidation of Carboxylic Acids and Aldehydes Over N-doped TiO₂ Loaded with Fe, Cu or Pt", Applied Catalysis B-Environmental, Vol. 83, No. 1/2 (2008), pp. 56-62. http://dx.doi.org/10.1016/j.apcatb.2008.01.034
   
• Yin, S., Liu, B., Zhang, P.L., Morikawa, T., Yamanaka, K. and Sato, T., "Photocatalytic Oxidation of NOx under Visible LED Light Irradiation over Nitrogen-doped Titania Particles with Iron or Platinum Loading", Journal of Physical Chemistry C, Vol. 112, No. 32 (2008), pp. 12425-12431. http://dx.doi.org/10.1021/jp803371s
   
• Asahi, R., Morikawa, T., Hazama, H. and Matsubara, M., "Materials Design and Development of Functional Materials for Industry", Journal of Physics-Condensed Matter, Vol. 20, No. 6 (2008). http://dx.doi.org/10.1088/0953-8984/20/6/064227
   
• Nakano, Y., Noda, K., Fujikawa, H. and Morikawa, T., "Emissive Interface States in organic Light-emitting Diodes based on Tris(8-hydroxyquinoline) Aluminum", Japanese Journal of Applied Physics, Vol. 47, No. 1 (2008), pp. 464-467. http://dx.doi.org/10.1143/JJAP.47.464

• Nakano, Y., Morikawa, T., Ohwaki, T. and Taga, Y., "Origin of Visible-light Sensitivity in N-doped TiO₂ Films", Chemical Physics, Vol. 339, No. 1/3 (2007), pp. 20-26. http://dx.doi.org/10.1016/j.chemphys.2007.05.031
   
• Asahi, R. and Morikawa, T., "Nitrogen Complex species and Its Chemical Nature in TiO₂ for Visible-light Sensitized Photocatalysis", Chemical Physics, Vol. 339, No. 1/3 (2007), pp. 57-63. http://dx.doi.org/10.1016/j.chemphys.2007.07.041
   
• Nakano, Y., Noda, K., Fujikawa, H. and Morikawa, T., "Deep-level Characterization of Emissive Interface States in Alq(3)-based OLEDs", Physica Status Solidi-Rapid Research Letters, Vol. 1, No. 5 (2007), pp. 196-198. http://dx.doi.org/10.1002/pssr.200701155
   
• Yoshinaga, M., Takahashi, H., Yamamoto, K., Muramatsu, A. and Morikawa, T., "Formation of Metallic Ni Nanoparticles on Titania Surfaces by Chemical Vapor Reductive Deposition Method", Journal of Colloid And Interface Science, Vol. 309, No. 1 (2007), pp. 149-154. http://dx.doi.org/10.1016/j.jcis.2007.01.051
   
• Nakano, Y., Noda, K., Fujikawa, H., Morikawa, T. and Ohwaki, T., "Deep-level Characterization of Tris(8-hydroxyquinoline) Aluminum with and without Quinacridone Doping", Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers, Vol. 46, No. 4B (2007), pp. 2636-2639. http://dx.doi.org/10.1143/JJAP.46.2636
   
• Nakano, Y., Morikawa, T. and Ohwaki, T., "Visible-light Sensitivity in N-doped ZnO Films Prepared by Reactive Magnetron Sputtering", Zinc Oxide And Related Materials, Vol. 957 (2007), pp. 289-294.

• Morikawa, T., Irokawa, Y. and Ohwaki, T., "Enhanced Photocatalytic Activity of TiO₂-xNx Loaded with Copper Ions under Visible Light Irradiation", Applied Catalysis A-General, Vol. 314, No. 1 (2006), pp. 123-127. http://dx.doi.org/10.1016/j.apcata.2006.08.011
   
• Nakano, Y., Noda, K., Fujikawa, H., Morikawa, T., Ohwaki, T. and Taga, Y., "Trap Levels in Tris(8-hydroxyquinoline) Aluminum Studied by Deep-level Optical Spectroscopy", Applied Physics Letters, Vol. 88, No. 25 (2006), 252104. http://dx.doi.org/10.1063/1.2214179
   
• Aoki, K., Morikawa, T., Ohwaki, T. and Taga, Y., "Photocatalytic Degradation of Formaldehyde and Toluene Mixtures in Air with a Nitrogen-doped TiO₂ Photocatalyst", Chemistry Letters, Vol. 35, No. 6 (2006), pp. 616-617. http://dx.doi.org/10.1246/cl.2006.616
   
• Nakano, Y., Morikawa, T., Ohwaki, T. and Taga, Y., "Electrical Characterization of p-type N-doped ZnO Films Prepared by Thermal Oxidation of Sputtered Zn₃N₂ Films", Applied Physics Letters, Vol. 88, No. 17 (2006), 172103. http://dx.doi.org/10.1063/1.2198489
   
• Nakano, Y., Morikawa, T., Ohwaki, T. and Taga, Y., "Band-gap Narrowing of TiO₂ Films Induced by N-doping", Physica B-Condensed Matter, Vol. 376 (2006), pp. 823-826. http://dx.doi.org/10.1016/j.physb.2005.12.206
   
• Irokawa, Y., Morikawa, T., Aoki, K., Kosaka, S., Ohwaki, T. and Taga, Y., "Photodegradation of Toluene over TiO₂-xNx under Visible Light Irradiation", Physical Chemistry Chemical Physics, Vol. 8, No. 9 (2006), pp. 1116-1121. http://dx.doi.org/10.1039/b517653k

• Nakano, Y., Morikawa, T., Ohwaki, T. and Taga, Y., "Deep-level Characterization of N-doped ZnO Films Prepared by Reactive Magnetron Sputtering", Applied Physics Letters, Vol. 87, No. 23 (2005), 232104. http://dx.doi.org/10.1063/1.2139852
   
• Nakano, Y., Morikawa, T., Ohwaki, T. and Taga, Y., "Electrical Characterization of Band Gap States in C-doped TiO₂ Films", Applied Physics Letters, Vol. 87, No. 5 (2005), 052111. http://dx.doi.org/10.1063/1.2008376
   
• Nakano, Y., Morikawa, T., Ohwaki, T. and Taga, Y., "Deep-level Optical Spectroscopy Investigation of N-doped TiO₂ Films", Applied Physics Letters, Vol. 86, No. 13 (2005), 132104. http://dx.doi.org/10.1063/1.1896450
   
• Morikawa, T., Asahi, R., Ohwaki, T., Aoki, K., Suzuki, K. and Taga, Y., "Visible-light Photocatalyst - Nitrogen-doped Titanium Dioxide – ", R&D Rev. Toyota CRDL, Vol. 40, No. 3, pp. 45-50.

• Nonomura, Y., Fujiyoshi, M., Omura, Y., Tsukada, K., Okuwa, M., Morikawa, T., Sugitani, N., Satou, S. and Kurata, N., "Quartz Rate Gyro Sensor for Automotive Control", Sensors and Actuators A-Physical, Vol. 110, No. 1/3 (2004), pp. 136-141. http://dx.doi.org/10.1016/j.sna.2003.10.048
   
• Nakamura, T., Morikawa T., Ohwaki, T. and Taga, Y., "Photocatalytic Activity of Sulfur-Doped TiO₂ Prepared via Thio Sol-Gel Process", Journal of the Ceramic Society of Japan, Supplement, Vol.112, (2004), S1422-S1424. http://doi.org/10.14852/jcersjsuppl.112.0.S1422.0

• Asahi, R., Morikawa, T., Ohwaki, T., Aoki, K. and Taga, Y., "Photocatalysts Sensitive to Visible Light - response", Science, Vol. 295, No. 5555 (2002), pp. 627-627. http://dx.doi.org/10.1126/science.1061051

• Asahi., R, Morikawa., T, Ohwaki., T, Aoki., K. and Taga, Y., "Visible-light Photocatalysis in Nitrogen-doped Titanium Oxides", Science, Vol. 293, No. 5528 (2001), pp. 269-271. http://dx.doi.org/10.1126/science.1061051
   
• Morikawa, T., Asahi, R., Ohwaki, T., Aoki, K. and Taga, Y., "Band-gap Narrowing of Titanium Dioxide by Nitrogen Doping", Japanese Journal of Applied Physics Part 2-Letters, Vol. 40, No. 6A (2001), pp. L561-L563. http://dx.doi.org/10.1143/JJAP.40.L561

• Morikawa, T., Suzuki, M. and Taga, Y., "Magnetic Properties of Granular Fe-Cr-O and Fe-X-Cr-O (X = Cu, Rh films)", Japanese Journal of Applied Physics Part 1-Regular Papers Short Notes & Review Papers, Vol. 38, No. 2A (1999), pp. 718-721. http://dx.doi.org/10.1143/JJAP.38.718

• Morikawa, T., Suzuki, M. and Taga, Y., "Improvement of Soft Magnetic Properties of Co-Cr-O film by Additional X(= Rh, Ir, Ag, or Au)", Japanese Journal of Applied Physics Part 2-Letters, Vol. 37, No. 7B (1998), pp. L866-L868. http://dx.doi.org/10.1143/JJAP.37.L866
   
• Morikawa, T., Suzuki, M. and Taga, Y., "Soft Magnetic Properties of Co-Cr-O Granular Films", Journal of Applied Physics, Vol. 83, No. 11 (1998), pp. 6664-6666. http://dx.doi.org/10.1063/1.367654

• Morikawa, T., Nishibe, Y., Yamadera, H., Nonomura, Y., Takeuchi, M. and Taga, Y., "Giant Magneto-impedance Effect in Layered Thin Films", IEEE Transactions On Magnetics, Vol. 33, No. 5 (1997), pp. 4367-4372. http://dx.doi.org/10.1109/20.620448

• Morikawa, T., Nishibe, Y., Yamadera, H., Nonomura, Y., Takeuchi, M., Sakata, J. and Taga, Y., "Enhancement of Giant Magneto-impedance in Layered Film by Insulator Separation", IEEE Transactions On Magnetics, Vol. 32, No. 5 (1996), pp. 4965-4967. http://dx.doi.org/10.1109/20.539303