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RESEARCH PROFILE

Professor Dr. Makoto Ogawa

School of Energy Science and Engineering (ESE)
Department of Chemical and Biomolecular Engineering
Tel. +66-33-014-255
Email makoto.ogawa@vistec.ac.th

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Synthesis and Photocatalyst Application of Layered Titanates

 

Research Overview

Preparation and characterization of layered titanates with controlled composition and particle morphology are investigated for optimized performances in the application.
The functionalization of layered titanates through cation exchange, grafting and nanoparticles immobilization for emerging useful photocatalyst performances such as efficient water splitting, molecular recognition and so on.

Layered Titanates

Layered inorganic solids, such as layered clay minerals and graphite, are composed of nanometer-thick layers assembled as alternating layer-by-layer manner. The interlayer can expand to accommodate guest species to give intercalation compounds. The interlayer reactivity (ion exchange, hydrogen bonding, redox etc.) of layered inorganic solids has been utilized for such applications as battery and adsorption. The layered materials and the intercalation compounds have been used as advanced materials as catalyst, catalyst support, adsorbent, electronic device, and drug carriers. Layered transition metal oxides are class of materials characterized by their useful electronic, magnetic, optical and catalytic properties Titanium oxide based layered materials have been synthesized and their ion exchange, electric and optical properties have been investigated so far. Here, some our previous studies on lepidocrocite- type layered titanates is introduced.

 

Lepidocrocite-type layered titanates are shown as A x Ti 2-yMyO4 , which are composed of titanate nanosheets and alkali metal ions in the interlayer space. The composition of the lepidocrocite-type layered titanate is versatile resulting in the varied swelling ability and ion exchange ability. Therefore, we have been interested in the preparation and application of layered titanates.

Synthesis Of Layered Titanate

Layered titanates are synthesized by solid state reaction. Preparations of layered titanates with varied layer charge density, which affected the cation exchange capacity, hydration and swelling of layered titanate. Layer charge density of Na x Ti 2-y Li yO4 was control by synthesis composition. The Na x Ti 2-y Li yO4 was the most hydrophilic titanate, which presented unique substrate selectivity in photocatalyst decomposition.

Photocatalyst

We have been investigating the photocatalytic performance of the layered titanates. Gold nanoparticle supported titanate was used for the oxidation of aqueous benzene to phenol, which is one of the most important chemical reaction in industry, with very high yields and efficiency. The molecular selective (enzymatic) photocatalytic decomposition of organics in water was also developed by the careful tuning of the interlayer reactivity. The photosensitization of layered titanate for visible light induced water splitting was also achieved in our laboratory.

Surface Modification Of Layered Titanate

The properties of layered titanate are modified by functionalization through cation exchange, grafting of organic functionality, and nanoparticles immobilization. Ruthenium complex was attached on surface of layered titanate as a sensitized layered titanate to produce hydrogen from water by visible light irradiation.

 

Selected Publications

  1. Miyamoto N., Kuroda K. and Ogawa M. J. Am. Chem. Soc., 123, 6949-6950 (2001).
  2. Kaito, R.; Miyamoto, N.; Kuroda, K.; Ogawa, M. J. Mater. Chem 12, 3463-3468 (2002).
  3. Ide Y., and Ogawa M. Chem. Commun. 11, 1262-1263 (2003).
  4. Miyamoto, N.; Kuroda, K.; Ogawa, M. J. Mater. Chem. 14, 165-170 (2004).
  5. Miyamoto, N.; Kuroda, K.; Ogawa, M. J. Phys. Chem. B 108, 4268-4274 (2004).
  6. Yui T., Tsuchino T., Itoh T., Ogawa M., Fukushima Y. and Takagi K. Langmuir 21, 2644-2646 (2005).
  7. Ide, Y.; Ogawa, M. J Colloid Interface Sci 296, 141-149 (2006).
  8. Ide Y. and Ogawa M. Angew. Chem. Int. Ed. Eng., 46, 8449-8451 (2007).
  9. Ide Y., Nakasato Y. and Ogawa M. J. Am. Chem. Soc., 132, 3601-3604 (2010).
  10. Ide, Y.; Matsuoka, M.; Ogawa, M.. J. Am. Chem. Soc. 132 , 16762-16764 (2010).
  11. Ogawa, M.; Morita, M.; Igarashi, S.; Sato, S., J. of Solid State Chem. 206, 9-13 (2013).
  12. Matsuoka, M.; Ide, Y.; Ogawa, M., Phys. Chem. Chem. Phys. 16, 3520-3522 (2014).
Reviews:
  1. Ogawa, M.; Saito, K.; Sohmiya, M., Dalton Trans. 43, 10340-10354 (2014).
  2. Ogawa M. and Kuroda K. Chem. Rev., 95, 399-438 (1995).
  3. Ide, Y.; Sadakane, M.; Sano, T.; Ogawa, M. J. Nanosci. Nanotechnol. 14, 2135-2147 (2014).
 

Research Group Members:

Dr. Makoto Ogawa (Professor)
Dr. Sareeya Bureekaew (Lecturer)
Dr. Surakerk Onsuratoom (Postdoctoral Research Fellow)
Dr. Tetsuo Yamaguchi (Postdoctoral Research Fellow)
Dr. Hojoon Shin (Postdoctoral Research Fellow)
Dr. Sebastian Bosch (Postdoctoral Research Fellow)
Ms. Thipwipa Sirinakorn
Mr. Kasimanat Vibulyaseak
Mr. Natthawut Homhuan
Ms. Kamonnart Imwiset
Ms. Aranee Teepakakorn
Mr. Wichayut Reanthonglert
Ms. Soontaree Intasa-ard