Shouheng Sun Professor of Chemistry, Professor of Engineering

Professor Sun received his PhD in Chemistry from Brown University in 1996. He joined the IBM T. J. Watson Research Center first as a postdoctoral fellow (1996-1998) and then as a research staff member (1998-2004). He returned to Brown in 2005 as a tenured faculty member and has been the Professor of Chemistry since 2008. He serves as the Co-Director of Brown's Institute for Molecular and Nanoscale Innovation (IMNI) and as an Associate Editor to the journal "Nanoscale" (the Royal Society of Chemistry).

Brown Affiliations

Research Areas

scholarly work

W. Zhu, R. Michalsky, Ö. Metin, H. Lv, S. Guo, C. Wright, X. Sun, A. A. Peterson, S. Sun, “Monodisperse Au Nanoparticles for Selective Electrocatalytic Reduction of CO2 to CO”, J. Am. Chem. Soc. 2013, 135, 16833–16836.

S. Guo, S. Zhang, S. Sun, “Tuning Nanoparticle Catalysis for Oxygen Reduction Reaction”, Angew. Chem. Int. Ed. 2013, 52, 52, 8526 – 8544. 

S. Guo, D. Li, H. Zhu, S. Zhang, N. M. Markovic, V. R. Stamenkovic, S. Sun, “MPt (M = Fe, Co) Nanowires as Efficient Catalysts for Oxygen Reduction Reaction”, Angew. Chem. Int. Ed. 2013, 52, 3465 –3468.

S. Guo, S. Zhang, L. Wu, S. Sun, “Co/CoO Nanoparticles Assembled on Graphene for Electrochemical Reduction of Oxygen”, Angew. Chem. Int. Ed. 2012, 51, 11770-11773.

S. Guo, S. Sun, "FePt Nanoparticles Assembled on Graphene as Enhanced Catalyst for Oxygen Reduction Reaction", J. Am. Chem. Soc. 2012, 134, 2492–2495.

S. Zhang, S. Guo, H. Zhu, D. Su, S. Sun, "Structure-Induced Enhancement in Electrooxidation of Trimetallic FePtAu Nanoparticles", J. Am. Chem. Soc. 2012, 134, 5060–5063.

J. Lee, S. Lee, G. Li, M. A. Petruska, D. C. Paine, S. Sun, "A Facile Solution-Phase Approach to Transparent and Conducting ITO Nanocrystal Assemblies", J. Am. Chem. Soc. 2012, 134, 13410–13414.

X. Sun, S. Guo, Y. Liu, S. Sun, "Dumbbell-like PtPd-Fe3O4 Nanoparticles for Enhanced Electrochemical Detection of H2O2", Nano Lett. 2012, 12, 4859–4863.

S. Guo, S. Zhang, L. Wu, S. Sun, "Co/CoO Nanoparticles Assembled on Graphene for Electrochemical Reduction of Oxygen", Angew. Chem. Int. Ed. 2012, 51, 11770 –11773.

D. Ho, X. Sun, S. Sun, "Monodisperse Magnetic Nanoparticles for Theranostic Applications", Acc. Chem. Res. 2011, 44, 875-882.

C. Xu, Z. Yuan, N. Kohler, J. Kim, M. A. Chung, S. Sun, "FePt Nanoparticles as an Fe Reservoir for Controlled Fe Release and Tumor Inhibition", J. Am. Chem. Soc. 2009, 131, 15346.

C. Wang, Y. Hu, C. M. Lieber, S. Sun, "Ultrathin Au Nanowires and Their Transport Properties", J. Am. Chem. Soc. 2008, 130, 8902.

C. Xu, J. Xie, D. Ho, C. Wang, N. Kohler, E. G. Walsh, J. R. Morgan, Y. E. Chin, S. Sun, "Au-Fe3O4 dumbbell nanoparticles as dual functional probes", Angew. Chem. Int. Ed. 2007, 47, 173.

S. Sun, "Recent advance in chemical synthesis, assembly and applications of FePt nanoparticles" (invited), Adv. Mater. 2006, 18, 393.

H. Yu, M. Chen, P. M. Rice, S. X. Wang, R. L. White, S. Sun, "Dumbbell-like bifunctional Au-Fe3O4 nanoparticles", Nano Lett .2005, 5, 379.

S. Sun, H. Zeng, D. B. Robinson, S. Raoux, P. M. Rice, S. X. Wang, G. Li, "Monodisperse MFe2O4 (M = Fe, Co, Mn) nanoparticles", J. Am. Chem. Soc. 2004, 126, 273.

S. Sun, H. Zeng, "Size-controlled synthesis of magnetite nanoparticles", J. Am. Chem. Soc. 2002, 124, 8204.

H. Zeng, J. Li, J. P. Liu, Z. L. Wang, S. Sun, "Exchanged-coupled nanocomposite magnets via nanoparticle self-assembly", Nature 2002, 420, 395.

C. T. Black, C. B. Murray, R. L. Sandstrom, S. Sun, "Spin-dependent tunneling in self-assembled cobalt nanocrystal superlattices", Science 2000, 290, 1131.

S. Sun, C. B. Murray, D. Weller, L. Folks, A. Moser, "Monodisperse FePt nanoparticles and ferromagnetic FePt nanocrystal superlattices", Science 2000, 287, 1989.

research overview

Professor Sun's research in nanomaterials involves two related areas: (1) chemical synthesis and self-assembly of nanoparticles; (2) construction and elaboration of functional nanoparticles and their assemblies for applications in biomedicine, catalysis, and magnetic energy storage.

research statement

Synthesis and Self-Assembly

Fundamental understanding of NP properties relies on NP uniformity in sizes, shapes, compositions and structures. This will lead to rational design and control of NPs for specific applications. We utilize the so called “bottom-up” approach to synthesize monodisperse NPs. By controlling chemical reaction conditions in solutions, we have atoms “build-up” to certain sizes and arrangement. As a result, we are able to tune NP sizes, compositions, and shapes. We are now exploring novel “bottom-up” approaches to prepare multi-component alloy, core/shell and dumbbell-like NPs. These NPs are stabilized by a lipid-type molecule (surfactant) and are readily dispersed in a specific solvent. The stable dispersion allows further NP surface modification and self-assembly. Therefore, these NPs can be tuned to have specific physical and chemical properties for important nano-technological applications.

Magnetic Nanoparticles for Biomedical Applications

With the dimension controls achieved from the “bottom-up” synthesis, magnetic NPs can be made ferromagnetic or superparamagnetic. Superparamagnetic NPs are especially important for biological applications as they have no net magnetization at the biologically relevant temperature and therefore no strong dipolar interactions, which facilitate their long-term stabilization. They can be magnetized under an external magnetic field, reaching ferromagnet-like magnetizations. Once properly functionalized, these NPs are bio-compatible and target-specific, and have been explored extensively as sensitive probes for magnetic resonance imaging, magnetic fluid hyperthermia and smart drug delivery.

Nanoparticles for Catalytic Applications

With the decrease in NP size, a large fraction of atoms become exposed. More importantly, NPs in this nanoscale regime have a large fraction of facets, edge- and corner-sites that may dominate the interaction between NP surface and molecules. Therefore, the controls of NP size, shape, composition achieved in the “bottom-up” synthesis are essential for rational tuning of NP electronic and geometric structures for catalytic applications. At present, we are developing efficient NP catalysts for applications in next generation energy devices, such as fuel cells, metal-air batteries and water-splitting cells, as well as in selective electrochemical reduction of CO2 to CO and other hydrocarbons.

Nanocomposites for Permanent Magnet Applications

Development of strong magnet for power and magnetic applications requires new materials with high energy density (kJ/m3). Nanocomposites containing exchange-coupled “hard” and “soft” phases in nanoscale can show much enhanced ferromagnetism and may serve as ideal materials for building super-strong magnets. We have been pursing chemical synthesis and self-assembly of magnetic NPs into nanocomposite magnets. By independently tuning the size and composition of each component, we are able to tailor the composite nanostructures and therefore their magnetic properties. Our studies provide both a model for fundamental understanding of magnetic properties within the nanostructures and a practical route to novel devices for magnetic energy storage applications.

funded research

DARPA/ARO: "High performance nanocomposite permanent magnets by rational assembly of nanoparticles", 2008 - 2012.

DOE/Argonne: "Nanosegregated Cathode Catalysts with Ultra-Low Platinum Content", 2009 - 2012.

DOE/Ames: "Beyond Rare-Earth Magnets", 2009-2014.

NSF/EFRI: "Integration of Dynamic Sensing and Actuating of Neural Microcircuits", 2009-2013.

DOE/Delaware: "Center for Spintronics and Biodetection", 2007- 2013.

ARO/MURI: "Stress-Controlled Catalysis via Engineered Nanostructures", 2011-2016.

NSF/CCI: "CO2 as a sustainable feedstock for chemical commodities", 2012-2015.

ExxonMobil Corporation, "Controlled Synthesis and Assembly of PdPt Nanocatalyst for Hydrogenation Reactions," 2009 - 2012.

Advanced Technology Materials, Inc, "Synthesis and Self-Assembly of ITO Nanoparticles", 2011-2013.