Combining chemistry and engineering to prepare well-defined nanostructured materials
Apr 21, 2017 | Atlanta
Younan Xia is the recipient of the 2017 Outstanding Faculty Research Author Award. Xia has joint appointments in three Georgia Tech academic units: the School of Chemistry and Biochemistry, the Wallace H. Coulter Department of Biomedical Engineering, and the School of Chemical and Biomolecular Engineering. Xia joined Georgia Tech in 2012 as the Brock Family Chair and Georgia Research Alliance Eminent Scholar in Nanomedicine.
Xia’s selection is based on creativity, breadth, insight, and leadership in various research areas, including rational syntheses of nanocrystals for catalysis, photonics, electronics, display, and medical applications. Xia’s contributions to chemistry, materials science, and biomedical engineering combine science and engineering to address the preparation and use of nanostructured materials.
A prolific researcher, Xia has been named among the Top 10 Chemists in 1999-2009 by Times Higher Education and the Top 100 Chemists and Top 100 Materials Scientists in 2000-2010 by Thomson Reuters. Xia has also been designated a Highly Cited Researcher in Chemistry and in Materials every year since the program’s launch in 2014 by Thomson Reuters.
Xia is recognized for pioneering expertise in applying physical principles to define the evolution of metal atoms to nanocrystals with well-controlled shapes and properties. Since joining Georgia Tech, Xia has focused on seed-mediated growth of metal nanocrystals. His methods enable precise control of size, shape, composition, and structure of the nanocrystals. Some key advances are illustrated by the following papers:
- “On the role of surface diffusion in determining the shape or morphology of noble-metal nanocrystals,” published in the Proceedings of the National Academy of Sciences, U.S.A. This 2013 paper reports Xia’s discovery that the relative rates of atom deposition and surface diffusion determine the growth pattern of a seed and thus the shape of products. The work led to a new protocol for coating metal nanocrystals with ultrathin shells of another metal.
- “Atomic Layer-By-Layer Deposition of Pt on Pd Nanocubes for Catalysts with Enhanced Activity and Durability toward Oxygen Reduction,” published in Nano Letters. This highly cited 2014 paper (137 citations and rising) indicates that core-shell bimetallic nanocrystals with enhanced activity, selectivity, and durability could replace heterogeneous catalysts now used in industrial processes.
- “Platinum nanocages with subnanometer-thick walls and well-defined, controllable facets,” published in Science. This 2015 paper offers a new design for next-generation catalysts. Xia prepared platinum nanocages enclosed by two different crystal facets, each with a distinct catalytic activity toward oxygen reduction, a key reaction in proton-exchange membrane fuel cells. Shortly after this paper came out, Xia received a two-year contract from Toyota Research Institute of North America to develop the platinum nanocages into catalysts for use in vehicles powered by hydrogen fuel cells.
Xia’s work on nanoparticles also have medical applications. For example, the 2014 review “Engineered nanoparticles for drug delivery in cancer therapy,” published in Angewandte Chemie International Edition, summarized the state-of-the-knowledge in cancer treatment using nanoparticles
“I am honored to receive this recognition,” says Xia. “I am grateful to my Ph.D. thesis advisor, Prof. George Whitesides at Harvard, who taught me the importance of having results published and, most importantly, how to put together a scientific publication effectively. I am also grateful to my former and current group members, as well as my collaborators, for their invaluable contributions.”