Toward a Quantitative Knob for Controlling the Synthesis of Colloidal Metal Nanocrystals: Nano Seminar Series

Seminar | April 21 | 2-3 p.m. | 390 Hearst Memorial Mining Building

 Prof. Younan Xia, Georgia Institute of Technology, BME / Chem

 Berkeley Nanosciences and Nanoengineering Institute

Recent studies suggest that reduction kinetics play an essential role in determining the outcome of a synthesis of colloidal metal nanocrystals. Reduction kinetics not only control the internal defect structure, including single-crystal, singly-twinned, multiply-twinned, and stacking-fault lined, of a seed formed in the nucleation step but also dictate the growth pattern (symmetric vs. asymmetric) or mode (island vs. layer-by-layer) of the seed in the subsequent steps.

In this talk, I will start with an introduction to our recent success in quantifying the kinetic parameters, including rate constants and activation energies, for a number of systems, and then illustrate how this knowledge can be applied to deepen our understanding of the nucleation and growth processes, moving toward the ultimate goal of achieving a quantitative and deterministic control over the synthesis. The quantitative knob based on reduction rate has enabled us to precisely and reproducibly tailor the properties of colloidal metal nanocrystals for a broad range of applications in photonics, catalysis, fuel cell technology, sensing, imaging, biomedicine.

Younan Xia did his PhD at Harvard with George Whitesides and then spent several years as chemistry professor at Univ. of Washington before moving to BME at GA Tech in 2012.