Abstract
Although the first documented synthesis of colloidal metal nanocrystals can be traced back to the beautiful work on gold colloids by Michael Faraday in 1856, only within the last decade have methods become available for generating samples with the quality, quantity, and reproducibility needed for a systematic study of their properties as a function of size, shape, and structure, and for exploration of their applications. Of particular importance is to control the shape of colloidal metal nanocrystals, which may initially seem like a scientific curiosity but with implications going far beyond aesthetic appeal. For nanocrystals made of noble metals, the shape determines their chemical, plasmonic, and catalytic properties, as well as their relevance for electronic, photonic and catalytic applications. For more than 15 years, the speaker and his group have been working diligently to understand the nucleation and growth mechanisms leading to the formation of nanocrystals with specific shapes and structures. They have discovered that the shape of metal nanocrystals are dictated by surface capping and the crystallinity and structure of seeds, which are, in turn, controlled by factors such as reduction kinetics and oxidative etching.
In this talk, the speaker will discuss some of the recent developments in this field, with a focus on shape-controlled synthesis of metal nanocrystals via seed-mediated growth in the presence/absence of a capping agent and under a thermodynamic or kinetic control. The success of these syntheses has enabled him to tailor the properties of metal nanocrystals for a broad range of applications in photonics, sensing, imaging, biomedicine, catalysis, and fuel cell technology.
About the speaker
Prof Younan Xia received his PhD in physical chemistry from Harvard University in 1996 and moved the University of Washington as an Assistant Professor in 1997. In 2007, he was appointed the James M. McKelvey Professor for Advanced Materials by the Washington University in St. Louis. He subsequently joined Georgia Institute of Technology in 2012 and is currently the Brock Family Chair and Georgia Research Alliance Eminent Scholar in Nanomedicine.
Prof Xia’s current research focuses on the design and synthesis of novel nanomaterials for a broad range of applications, including nanomedicine, regenerative medicine, cancer theranostics, tissue engineering, controlled release, catalysis, and fuel cell technology.
Prof Xia was elected Fellow of the American Chemical Society (2014); the American Institute for Medical and Biological Engineering (2011); and the Materials Research Society (2009). He received numerous honors including the Nano Today Award (2013); the National Award in the Chemistry of Materials by the American Chemical Society (2013); the Fred Kavli Distinguished Lectureship in Nanoscience by the Materials Research Society (2013) and the NIH Director's Pioneer Award by the US National Institutes of Health (NIH)(2006).
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