Award type：Award from international society, conference, symposium, etc.  Country：Japan

Among several zeolitic imidazole frameworks (ZIFs), ZIF-8, in which 2-methylimidazole and Zn ions are arranged regularly, has garnered significant attention due to its unique crystal and pore structures. Various sizes and shapes of ZIF-8 crystals have been reported based on synthesis parameters such as the molar ratio of organic ligands and metal ions, solvent, and temperature1. However, the existence of large-scale single-crystal ZIF-8 has not been explicitly reported through photographic evidence. Herein, we present the synthesis of millimetre-sized single crystal ZIF-8 using the solvothermal method in N,N-diethylformamide (DEF). The resulting 1-mm single crystal is growth via the solvothermal method at 120°C for 72 h. The crystal was characterized through N2 adsorption-desorption isotherms, scanning electron microscope (SEM), and other analytical techniques. Additionally, single crystal X-ray diffraction is employed to comprehensively investigate the framework mobility at various temperatures (100 to 500K).

Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

Language：English   Publisher：Science and Technology of Advanced Materials  

Among various metal-organic frameworks (MOFs), the zeolitic imidazole framework (ZIF), constructed by the regular arrangement of 2-methylimidazole and metal ions, has garnered significant attention due to its distinctive crystals and pore structures. Variations in the sizes and shapes of ZIF crystals have been reported by changing the synthesis parameters, such as the molar ratios of organic ligands to metal ions, choice of solvents, and temperatures. Nonetheless, the giant ZIF-8 single crystals beyond the typical range have rarely been reported. Herein, we present the synthesis of millimeter-scale single crystal ZIF-8 using the solvothermal method in N,N-diethylformamide. The resulting 1-mm single crystal is carefully characterized through N2 adsorption-desorption isotherms, scanning electron microscopy, and other analytical techniques. Additionally, single-crystal X-ray diffraction is employed to comprehensively investigate the framework’s mobility at various temperatures.

DOI： 10.1080/14686996.2023.2292485

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PubMed

Publishing type：Research paper (scientific journal)  

DOI： 10.1039/d2ta06307g

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Language：English   Publisher：Nano Letters  

Bi2Se3 is a semiconductive material possessing a bandgap of 0.3 eV, and its unique band structure has paved the way for diverse applications. Herein, we demonstrate a robust platform for synthesizing mesoporous Bi2Se3 films with uniform pore sizes via electrodeposition. Block copolymer micelles act as soft templates in the electrolyte to create a 3D porous nanoarchitecture. By controlling the length of the block copolymer, the pore size is adjusted to 9 and 17 nm precisely. The nonporous Bi2Se3 film exhibits a tunneling current in a vertical direction of 52.0 nA, but upon introducing porosity (9 nm pores), the tunneling current increases significantly to 684.6 nA, suggesting that the conductivity of Bi2Se3 films is dependent on the pore structure and surface area. The abundant porous architecture exposes a larger surface area of Bi2Se3 to the surrounding air within the same volume, thereby augmenting its metallic properties.

DOI： 10.1021/acs.nanolett.3c00183

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PubMed

Language：English   Publisher：Chemistry - A European Journal  

CsCl-type intermetallic compounds TiM (M=Co, Fe) were obtained by deoxidizing trigonal ilmenite-type MTiO3 with a reducing agent CaH2 in molten LiCl at 600 °C. X-ray diffraction, nitrogen adsorption, scanning electron microscopy, and transmission electron microscopy with energy-dispersive X-ray, and X-ray photoelectron spectroscopy analyses revealed the formation of nanoscale layered structures, which enhanced specific surface areas (approximately 20 m2/g) in the intermetallic compounds. In the initial deoxidation stage, Li2TiO3-like compounds were observed as an intermediate, suggesting the substitution of M in MTiO3 by Li from the molten LiCl. Compound MTiO3 has a layered structure perpendicular to the c axis of the trigonal structure, suggesting that the layered structures may originate from the crystal structure of the precursors. Formation of the Li2TiO3-like intermediate may help maintain the original layered structure during deoxidation and the subsequent alloying at temperatures as low as 600 °C.

DOI： 10.1002/chem.202300194

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PubMed

Language：English   Publisher：Chemical Communications  

Pyrolysis-free metal-organic frameworks (MOFs) with optimized particle sizes were used as capacitive deionization (CDI) materials in oxygenated saline water. Upon decreasing the particle size of the MOFs, excellent cycling stability and higher CDI performance were achieved. This was possibly due to the improvement in charge transfer and electrolyte permeation, uncovering the significance of particle size control in improving CDI performance.

DOI： 10.1039/d2cc06460j

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PubMed

Event date： 2017.4

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Country：Japan  

Event date： 2024.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2023.7

Language：English  

Country：Japan