SPring-8, the large synchrotron radiation facility

Scientists from Kyushu University (Setsuo Arikawa, President) and Japan Synchrotron Radiation Research Institute (JASRI; Tetsuhisa Shirakawa, President) have jointly succeeded in developing a highly oriented porous nanocrystalline thin film and analyzing its surface architecture for the first time in the world.  The establishment of this new method of fabricating such films is expected to lead to the development of highly efficient electrode catalysts with unprecedentedly high stability.  This was achieved by a joint research group including Professor Hiroshi Kitagawa at Kyoto University, who was also an invited professor at Kyushu University until March 2010, and Osami Sakata, a senior scientist at JASRI.

Adsorbents, typified by activated carbon, take in and adsorb molecules, and are called porous substances because they have many internal pores.  Porous metal complexes, which exhibit higher selective gas adsorption than activated carbon and zeolites, have attracted attention since the late 1990s as porous substances with highly efficient functions of separation and condensation.  The research and development of porous metal complexes is being carried out worldwide.  In recent years, several porous metal complexes that selectively adsorb CO₂ with high efficiency have been developed and considered for use in technology for reducing CO₂ emissions, because their characteristic flexible structure requires little energy for desorption.  On the other hand, there has been a great deal of interest in the technology of stacking films of porous metal complexes on the surface of a substrate by the self-organization method^*1 or layer-by-layer method^*2 to form a laminated nanofilm; however, no scientists have succeeded in fabricating a nanocrystalline thin film with high crystalline order, i.e., a highly oriented porous nanocrystalline thin film.

The above research group has succeeded in fabricating a highly oriented porous nanocrystalline thin film by making full use of various nanotechnologies and has clarified its structure using the advanced measurement technology available at SPring-8.  The achievements of this study are expected to greatly accelerate the development of highly efficient electrode catalysts, nanointerfacial devices, energy nanodevices, and other applications.

This research was carried out as part of the "Creation of the Metal-Organic Hybrid Protonics and Functional Nano-Layer Integrated System"project (Hiroshi Kitagawa, Research Director) within the research scope of the "Development of the Foundation for Nano-Interface Technology" project of the Core Research for Evolutional Science and Technology (CREST) supported by the Japan Science and Technology Agency (JST).  It was also accepted by JASRI as a research project utilizing SPring-8.

The original paper on the results of this research was published in the advance online publication of the British scientific journal Nature Materials on 30 May 2010.

Publication:
"Surface Nano-Architecture of A Metal-Organic Framework"
R. Makiura, S. Motoyama, Y. Umemura, H. Yamanaka, O. Sakata, H. Kitagawa
Nature Materials, Volume 9, 565–571 (2010), Published online 30 May 2010