Crystal design leads to enhanced performance

Crystal growth and structural design are critical for achieving high efficiency in (photo)electrochemical and photocatalytic processes. The performance of semiconducting materials depends on key parameters, such as photon absorption, charge generation, separation, and transport, and surface reactivity. These parameters can be systematically modulated through control of crystal morphology, size, dimension, porosity, and facet exposure, which govern defect density, crystallinity, electronic structure, surface area, and the distribution of active sites. Rational design of these structural attributes enables precise tuning of light harvesting efficiency, charge carrier dynamics, and interfacial reaction kinetics. Transition metal (oxy)nitrides often suffer from performance limitations due to high defect densities arising from conventional synthesis routes. To overcome these challenges, we employ a range of synthetic strategies, from soft chemical synthesis to high-temperature solid-state reactions, in our research lab. Particularly, we apply flux-mediated crystal growth as one of the effective techniques to grow (oxy)nitride crystals with well-defined morphologies, sizes, and facet orientations. Systematic investigation of these crystal growth and design parameters provides deeper insights into optimizing transition metal (oxy)nitrides for solar energy conversion and related catalytic applications.

Relevant Publications

[1] M. Hojamberdiev and K. Kawashima, Exploring flux-grown perovskite transition metal oxynitrides for photocatalytic water splitting: A minireview, Energy Reports, 2020, 5, 13–24.
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[2] M. Hojamberdiev, Y. Cai, Junie J.M. Vequizo, M. Mansoob Khan, R. Vargas, K. Yubuta, A. Yamakata, K. Teshima and M. Hasegawa, Binary flux-promoted formation of trigonal ZnIn₂S₄ layered crystals using ZnS-containing industrial waste and their photocatalytic performance for H₂ production, Green Chemistry, 2018, 20, 3845–3856.
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[3] M. Hojamberdiev, M.F. Bekheet, E. Zahedi, H. Wagata, Y. Kamei, K. Yubuta, A. Gurlo, N. Matsushita, K. Domen and K. Teshima, New Dion−Jacobson Phase Three-Layer Perovskite CsBa₂Ta₃O₁₀ and Its Conversion to Nitrided Ba₂Ta₃O₁₀ Nanosheets via Nitridation-Protonation-Intercalation-Exfoliation Route For Water Splitting, Crystal Growth and Design, 2016, 16, 2302−2308.
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[4] M. Hojamberdiev, K. Yubuta, J.J. M. Vequizo, A. Yamakata, S. Oishi, K. Domen and K. Teshima, NH₃-Assisted Flux Growth of Cube-Like BaTaO₂N Submicron Crystals in a Completely Ionized Nonaqueous High-Temperature Solution and Their Water Splitting Activity, Crystal Growth and Design, 2015, 15, 4663–4671.
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