Welcome to Vidyasirimedhi Institute of Science and Technology. Website from Thailand
LOGIN

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
Webpage Go to Webpage

DETAIL  

Controlled Synthesis of Well-Defined Layered Double Hydroxides

 

Research Overview

Layered double hydroxides have emerged as efficient layered materials according to their versatility in composition, morphology, and reactivity. They have been used in a wide range of applications including catalysts, catalyst supports, adsorption and separation, and filler. In order to optimize the properties of layered double hydroxides and their derivatives, the synthetic methods have been optimized and new methods have been developed toward precisely controlled morphology and composition, as well as productivity for practical applications.

Layered Double Hydroxides

Layered double hydroxides (LDHs) are a class of two-dimensional anionic clays. The structure of these layered materials is based on positively charged brucite-like layers in which divalent metal cations occupy octahedrally coordinated positions in the layered structure. Some portion of divalent metal cations are isomorphously replaced by trivalent metal cations to generate net positive charge, which are compensated with exchangeable anions located in the interlayer region. LDHs can be represented by the general formula of [M1−x2+Mx3+(OH)2]x+(An−)x/n·mH2O, where M2+ and M3+ are divalent and trivalent cations, respectively; the value of x is equal to the molar ratio of M3+ /(M2+ + M3+), where A is the interlayer anion of valence n.


Scheme of layered double hydroxides physical appearance and morphology

The cation in the brucite layer, the anion in the interlayer region and the ratio between divalent and trivalent cations can vary to give a class of isostructural materials with variable physicochemical properties. These materials variation make them useful for a wide range of applications like polymer additive, catalyst and its support, adsorbent, drug delivery, slow-release fertilizer, and thin films.

Synthetic efforts have been done to design structural and morphological features of well-defined particles with improved materials’ performance. The syntheses under mild conditions are another issue for green chemistry concepts. Due to the high anion exchange capacity of LDHs, functional organic anions or molecules can be further intercalated in the interlayer space of LDHs, which results organic-inorganic hybrids with unique function to which host or guest alone does not have access.

Syntheses of Layered Double Hydroxides

Layered double hydroxides can be synthesized by different methods including homogeneous precipitation from aqueous solution or urea hydrolysis under hydrothermal conditions. It has been shown successfully, that the composition and morphology of LDHs can be controlled by the adjustment of the synthesis conditions like temperature and concentration in order to obtain well-defined particles with narrow size-distribution. Moreover, with a newly developed pH adjustment method using ion- exchange resin the controlled synthesis of finite particles has been reported. Furthermore, the defined intercalation of organic guest molecules in the interlayer space of LDHs has been achieved in order to prepare organic-inorganic hybrids with novel material properties. For the first time, the direct correlation between nanostructure and particle morphology during intercalation has been visualized which confirmed the topochemical reaction of the intercalation.

Scheme of a brucite-like LDH structure Scheme of layered double hydroxides synthesis

Applications

Besides our interest in the preparation of well-defined LDHs, we are investigating these layered materials in different applications. Due to their high anion exchange capacity, LDHs have shown to be very efficient for water treatment applications like the removal of colloidal particles or heavy metals like chromium in aqueous solution. Furthermore, the intercalation of various organic anions or functional molecules inside the interlayer space of LDH can be used to prepare organic-inorganic hybrids for photochromic applications and as photocatalytic materials. In addition, well-defined LDH particles can serve as template for the preparation of other microporous materials.
Scheme of the efficient immobilization of colloidal β-FeOOH particles from aqueous solution with LDHs
 

Selected Publications

  1. Ogawa M., Asai S. Chemistry of Material 12, 3253-3255 (2000).
  2. Ogawa M., Kaiho H. Langmuir 18, 4240-4242 (2002).
  3. Ogawa M., Saito F. Chemistry Letters 33, 1030-1031 (2004).
  4. Ogawa M., Inomata K. Chemistry Letters 34, 810-811 (2005).
  5. Kayano M., Ogawa M. Bulletin of the Chemistry Society of Japan 79, 1988-190 (2006).
  6. Kayano M., Ogawa M. Clays and Clay Minerals. 54, 382-389 (2006).
  7. Inomata K., Ogawa M. Bulletin of the Chemistry Society of Japan 79, 336-342 (2006).
  8. Shimura N., Ogawa M. Journal of Colloid and Interface Science 312, 311-316 (2007).
  9. Arai Y., Ogawa M. Applied Clay Science 42, 601-604 (2009).
  10. Ogawa M., Sugiyama Y. Journal of the Ceramic Society of Japan 117, 179-184 (2009).
  11. Nioh K., Ayral A. Ogawa M. Chemistry Letters 39, 1018-1019 (2010).
  12. Arai Y., Ogawa M. Applied Clay Science 42, 601-604 (2009).
  13. Kuramoto K., Ogawa M. Bulletin of the Chemistry Society of Japan 84, 675-677 (2011)
  14. .
  15. Naito S., Nitoh K., Ayral A., Ogawa M. Industrial & Engineering Chemistry Research 51, 14414-14418 (2012).
  16. Kaneko S., Ogawa M. Applied Clay Science 75, 109-113 (2013).
  17. Ogawa M., Kaneko S. Langmuir 29, 14469-14472 (2013).
  18. Ogawa M., Hiramine M. Crystal Growth & Design 14, 1516-1519 (2014).
Reviews:
  1. Ogawa M., Inomata K. Clay Science 15, 131-137 (2011).
  2. Ogawa M., Kuroda K. Chemical Review 95, 399-438 (1995).
  3. Okada T., Ide Y., Ogawa M. Asian Journal of Chemistry 7, 1980-1992 (2012).
  4. Okada T., Sohmiya M., Ogawa M. Structure and Bonding 166, 177-211 (2015).
 

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