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Nanoparticle Synthesis 목록
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Nanoparticle Synthesis

Nanoparticles can be made using different methods. Our group has developed a versatile synthetic technique called the "heat-up process." It allows us to produce uniformly sized nanoparticles of various transition metals, oxides, and semiconductors without needing a size selection step. With this process, we can synthesize monodisperse nanocrystals on a large scale (up to tens of grams). Additionally, we use non-hydrolytic sol-gel reactions to synthesize different transition metal oxide nanocrystals.

Moreover, we employ "Galvanic replacement" to synthesize nanomaterials with substituted metals. These materials exhibit interesting physical properties compared to their original forms. We're also interested in synthesizing sub-nanometer materials called nanoclusters, which have unique properties. Ultimately, our research focuses on understanding the mechanism behind nanoparticle synthesis, particularly in the early stages, based on our studies of nanoclusters.

Also, understanding shape control in nanocrystals is crucial for leveraging their structure-property relationship. The high surface-to-volume ratio of nanocrystals leads to dynamic surface reactions, like adsorption and diffusion of surface atoms, influencing shape transformation. However, tracking these transformations at the facet level is challenging. We investigate individual facet changes in shape of nanocrystals transformation using liquid phase TEM and kinetic Monte Carlo simulations. This shows that surface atom diffusion governs shape transformation, driving unstable facets to a truncated morphology with lower surface energy. This insight into surface diffusion aids in understanding nanocrystal formation mechanisms.

References

Jongnam Park, Kwangjin An, Yosun Hwang, Je-Geun Park, Han-Jin Noh, Jae-Young Kim, Jae-Hoon Park, Nong-Moon Hwang & Taeghwan Hyeon "Ultra-large-scale syntheses of monodisperse nanocrystals", Nature Materials 2004, 3, 891–895

Myoung Hwan Oh, Taekyung Yu, Seung-Ho Yu, Byungkwon Lim, Kyung-Tae Ko, Marc-Georg Willinger, Dong-Hwa Seo, Byung Hyo Kim, Min Gee Cho, Jae-Hoon Park, Kisuk Kang, Yung-Eun Sung, Nicola Pinna, Taeghwan Hyeon "Galvanic Replacement Reactions in Metal Oxide Nanocrystals", Science 2013, 340 (6135), 964-968.

Back Kyu Choi, Jeongwon Kim, Zhen Luo, Joodeok Kim, Jeong Hyun Kim, Taeghwan Hyeon*, Shafigh Mehraeen*, Sungho Park, and Jungwon Park "Shape Transformation Mechanism of Gold Nanoplates", ACS Nano 2023, 17 (3), 2007–2018