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).

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

Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.pmatsci.2025.101427

Web of Science

Scopus

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Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Abstract

Tin halide perovskites are promising candidates for lead‐free perovskite solar cells due to their ideal bandgap and high charge‐carrier mobility. However, poor crystal quality and rapid degradation in ambient conditions severely limit their stability and practical applications. This study demonstrates that incorporating UiO‐66, a zirconium‐based MOF, significantly enhances the performance and stability of tin halide perovskite solar cells (TPSCs). The unique porous structure and abundant carboxylate groups of UiO‐66 improve the crystallinity and film quality of FASnI₃, reduce defect density, and prolong charge carrier lifetimes. Consequently, the power conversion efficiency (PCE) of UiO‐66‐integrated TPSCs increases from 11.43% to 12.64%, and the devices maintain over 90% of their initial PCE after 100 days in a nitrogen glovebox. These findings highlight the potential of UiO‐66 in addressing the efficiency and stability challenges of tin halide perovskites.

DOI： 10.1002/smll.202411346

Web of Science

PubMed

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Publishing type：Research paper (scientific journal)  

DOI： 10.1093/bulcsj/uoae136

Web of Science

Scopus

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Language：English   Publisher：ACS Nano  

Although hierarchical porous carbon materials have been widely used for electrocatalysis, the role of curvature in carbon nanostructures during electrochemical reactions remains poorly understood due to a lack of experimental models featuring clearly defined curved geometries and periodic structures. In this study, we fabricate hierarchical porous cobalt- and nitrogen-containing carbon nanoplates with trimodal porosity (macro-, meso-, and micropores) and continuous, homogeneous curved edges (Co/N-CNP-CURV) using a polystyrene-directed templating approach. The Co/N-CNP-CURV catalyst exhibits excellent catalytic activity and stability for the alkaline oxygen reduction reaction, with a half-wave potential of 0.82 V and a minimal potential shift of 8 mV after 5000 cycles. The enhanced electrocatalytic activity is attributed to synergistic combinations of the trimodal porosity, abundant Co-Nx active sites, a high density of curved edges, and graphitic carbon encapsulated with cobalt nanoparticles. Density functional theory calculations reveal that the presence of curvature in Co/N-CNP-CURV is beneficial for enhancing the charge transfer from the catalyst to O2, lowering the adsorption energy of O2, and reducing the activation free energy barrier for the rate-determining step (*O2 + (H+ + e-) → *OOH). The study provides compelling experimental evidence supporting the critical role of the curvature effect in enhancing the electrocatalytic performance of nanoporous metal-containing carbon materials.

DOI： 10.1021/acsnano.4c06404

Scopus

PubMed

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Informa UK Limited  

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

Open Access

Web of Science

Scopus

PubMed

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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  

Event date： 2012.8

Language：Japanese   Presentation type：Poster presentation  

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