87th CEMS Colloquium

Speaker

Prof. Hiroshi Kitagawa (Kyoto University)

Date

17:30 - 18:30, December 23, 2020 (Wednesday)

Venue

Okochi-Hall, RIKEN

Title

Density-of-States Engineering for New Nano-Materials: Binary to High-Entropy Alloys

Abstract

Platinum group metal (PGM) nanoparticles (NPs) have been investigated in a variety of research fields such as catalysis and electronics. Among the types of alloys, solid-solution alloy NPs have the advantage of being capable of continuously changing their properties by tuning their composition. However, synthesizing PGM solid-solution alloy NPs with any combination and composition is not an easy task due to the metallurgical aspects. In this work, we have focused on PGM-based solid-solution alloy NPs, and in particular those with immiscible alloy systems1-7.

The physical and chemical properties of most solids are strongly correlated to their electronic structure, in particular the DOS at the EF. In 2015, our group proposed the “DOS engineering” concept for designing materials4, which calls for the control not only of the location of the d-band center, but also of a suitable DOS shape, such as the band width and the DOS shape of unoccupied and occupied stated around EF.

We propose that by means of “interelement fusion,” as shown in Figure 1 where the elemental periodic table is colored by the s, p, d, and f groups, it is possible to manipulate the shape of the DOS freely by choosing elements from the s, p, d, and f groups according to the properties desired.

Figure 1: Interelement fusion strategy based on DOS Engineering.

References:

  1. K. Kusada, D. Wu, H. Kitagawa, Chem. – Eur. J., in press (Review). 
  2. Q. Zhang, K. Kusada, D. Wu, H. Kitagawa, Nat. Commun., 9, 510 (2018). 
  3. K. Kusada and H. Kitagawa, Adv. Mater., 28, 1129 (2016) (Review). 
  4. H. Kobayashi, K. Kusada, H. Kitagawa, Acc. Chem. Res., 48, 1551 (2015) (Review). 
  5. F. Wang, K. Kusada, D. Wu, H. Kitagawa, Angew. Chem. Int. Ed., 57, 4505 (2018). 
  6. T. Wakisaka, K. Kusada, D. Wu, S. Matsumura, H. Kitagawa, J. Am. Chem. Soc., 142, 1247 (2020). 
  7. K. Kusada, D. Wu, S. Matsumura, M. Koyama, H. Kitagawa, Chem. Sci., 10, 652 (2019).
  8. D. Wu, K. Kusada, T. Yamamoto, T. Toriyama, S. Matsumura, S. Kawaguchi, Y. Kubota, H. Kitagawa, J. Am. Chem. Soc., 142, 13833 (2020). 
  9. D. Wu, K. Kusada, T. Yamamoto, T. Toriyama, S. Matsumura, G. Ibrahima, O. Seo, J. Kim, S. Hiroi, O. Sakata, S. Kawaguchi, Y. Kubota, H. Kitagawa, Chem. Sci., in press. (Invited to 10th Anniversary Issue).
  10. K. Kusada, D. Wu, H. Kitagawa, Chem. – Eur. J., 26, 5105 (2020) (Invited Review).