ADVENTURES IN COLLOIDAL NANOCRYSTAL SURFACE CHEMISTRY
חדר סמינרים הפקולטי
Prof. Richard L. Brutchey Department of Chemistry, University of Southern California, Los Angeles, CA, USA
סמינר כימיה פיסיקלית ואנליטית
Adventures in Colloidal Nanocrystal Surface Chemistry
Colloidal nanocrystals possess high surface area-to-volume ratios; as a result, many nanocrystal properties are heavily influenced by their surfaces. At these surfaces exists a complex interface between the inorganic solid (governed by the crystal structure and particle morphology) and organic ligands. The organic ligands play a key role in controlling nucleation and growth, passivating under-coordinated surface sites, and providing steric stabilization for solvent dispersibility. Depending on the particular application of the nanocrystal, the native organic ligands may then need to be removed or exchanged. We use a complement of NMR spectroscopic techniques to understand the nature of the nanocrystal surface and ligand binding. Then, using principles of inorganic coordination chemistry, we rationally enact ligand exchange reactions on these surfaces to maximize nanocrystal functionality. This talk will briefly discuss the surface chemistry of three different platforms. (1) I will discuss how we experimentally developed an atomistic picture of perovskite nanocrystal surface termination, and then used that information to better understand how common surface treatments can “heal” nanocrystal surfaces. (2) I will discuss how different s-donating, L-type ligands were installed on the surface of metal phosphide nanocrystals, and how they affected the hydrogen evolving ability of these electrocatalysts. (3) I will discuss a new strategy for thermally activating metal carbide nanocrystal CO2 reduction catalysts using labile ligands that decompose at significantly lower temperatures than the native ligands. This circumvents issues commonly encountered with high-temperature thermolysis (coking) or acid treatments (etching, poisoning) that are traditionally used to activate nanocrystal catalysts.
Richard L. Brutchey received his B.S. in chemistry from the University of California, Irvine (2000) and his Ph.D. in chemistry from the University of California, Berkeley (2005). After a post-doctoral fellowship at the University of California, Santa Barbara, he began his independent career in 2007 at the University of Southern California where he is currently a Professor of Chemistry. The Brutchey group develops new methods of inorganic material synthesis to address challenges related to catalysis, energy storage and conversion, and sustainability. He is the recipient of a Cottrell Scholar award by the Research Corporation for Science Advancement (2010), was named a Chemical Communications Emerging Investigator and Dalton Transactions New Talent Honoree (2012), was the recipient of two Scialog® awards for solar energy conversion (2014 & 2015), the RCSA Singular Exceptional Endeavor of Discovery Award (2020) and the 2020 ACS Nanoscience Award. His work has been highlighted by Forbes, National Geographic magazine, and National Public Radio. He has held appointments as a visiting professor at the Swiss Federal Institute of Technology Zürich in 2014 and as the Joseph Meyerhoff Visiting Professor at the Weizmann Institute of Science in 2022.