Dr. Janet McDonald (Vanderbilt University) will present “Nanostructures of Cu and Mo Sulfides: New chemistry from the surface to the core” to the department.

Abstract: Since our community began focusing on the “bottom-up” synthesis of nanoparticles and nanomaterials, our synthetic control has developed from control of the size of spherical, single component nanoparticles, to materials of increasing compositional complexity and structural design. These added design components lead to heightened functionality. In the Macdonald research laboratory, we allow a desired function, such as electrocatalytic reactivity or photocatalytic activity, to inspire new designs of nanoparticles. Our journey to achieve these goals leads to making fundamental discoveries about surface chemistry, crystalline order and reactivity. Our efforts have focused lately on a new binding mode of thiols on nanoparticle surfaces, that makes particles less prone to oxidation or ligand loss, and improves charge transfer in photocatalytic reactions. In a second project, we study the formation mechanism, the NIR luminescence and its origin in wurtzite CuInS2, a form only found in nanocrystals. Along the way we discovered an unreported type of crystalline order in mixed cation sulfides such as CuInS2 with sweeping implications for opto-electronic and thermo-electronic properties for these materials. In the last project presented here, we have developed petaled nanostructured cathodes of MoS2 that outperform Pt in Quantum Dot Sensitized Solar Cells.