Identification of solids for true design and precise characterization of functional materials

Identification of solids for true design and precise characterization of functional materials

7^th International Conference on MATERIALS SCIENCE AND ENGINEERING
November 14, 2022 | Webinar

Bunsho Ohtani

Hokkaido University, Japan

Scientific Tracks Abstracts : Mater Sci Nanotechnol

Abstract:

How can we design functional solid materials, such as catalysts and photocatalysts? What are the decisive structural parameters controlling their activities, performance or properties? What is obtained as structural properties by popular conventional analytical methods, such as X-ray Diffraction (XRD) or nitrogen-adsorption measurement, is limited to bulk crystalline structure and specific surface area, i.e., no structural characterization on amorphous phases, if present, and surface structure has been made so far. This is because there have been no macroscopic analytical methods to give surface structural information including possibly present amorphous phases. Recently, we have developed Reversed Double-Beam Photoacoustic Spectroscopy (RDB-PAS) which enables measure Energy-Resolved Distribution of Electron Traps (ERDT) for semiconducting materials such as metal oxides [1, 2]. Those detected Electron Traps (ETs) seem to be predominantly located on the surface for almost all the metal oxide particles, and therefore they reflect macroscopic surface structure, including amorphous phases, in ERDT patterns. Using an ERDT pattern with the data of CB bottom position (CBB), i.e., an ERDT/CBB pattern, it has been shown that metal oxide powders, and the other semiconducting materials such as carbon nitride, can be identified without using the other analytical data such as XRD patterns or specific surface area, and similarity/differentness of a pair of metal-oxide samples can be quantitatively evaluated as degree of coincidence of ERDT/CBB patterns. In this talk, an approach of material design based on the ERDT/CBB-pattern analyses is introduced [3]. [1] Chem. Commun., 2016, 52, 12096–12099. [2] Electrochim. Acta, 2018, 264, 83–90. [3] Catal. Today, 2019, 321–322, 2–8. References 1. Zhang, Li & Chuaicham, Chitiphon & Balakumar, Vellaichamy & Sekar, Karthikeyan & Ohtani, Bunsho & Sasaki, Keiko. (2022). Determination of the roles of FeIII in the interface between titanium dioxide and montmorillonite in FeIII-doped montmorillonite/titanium dioxide composites as photocatalysts. Applied Clay Science. 227. 106577. 10.1016/j.clay.2022.106577. 2. Amalia, Fitri & Takashima, Mai & Ohtani, Bunsho. (2022). Are You Still Using Organic Dyes? Colorimetric Formaldehyde Analysis for True Photocatalytic-activity Evaluation. Chemical Communications. 58. 10.1039/D2CC04291F. 3. Csóka, Levente & Hosakun, Worakan & Kolonics, Ottó & Ohtani, Bunsho. (2022). Reversed double-beam photoacoustic spectroscopic analysis of photoinduced change in absorption of cellulose fibres. Scientific Reports. 12. 10.1038/s41598-022- 18749-w.

Biography:

Bunsho Ohtani was a Ph. D. course student in Kyoto University when the research work on material chemistry was started in 1981. Since then, he has been studying photocatalysis and related topics for 40 years and published more than 300 original papers (h-index: 72). After gaining his Ph. D. degree from Kyoto University in 1985, he became an assistant professor in the university. In 1996, he was promoted to an associate professor in Graduate School of Science, Hokkaido University and was then awarded a full professor position in Institute for Catalysis, Hokkaido University in 1998 and retired at the end of March 2022.

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