Contact
G-10 CHVRNPittsburgh, PA 15260
412-624-8430
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Research Overview
Professor Waldeck's research program uses methods of spectroscopy, electrochemistry, and microscopy to examine the nature of the Chiral-Induced Spin Selectivity (CISS) effect and to explore ways in which it can be exploited technologically. First discovered in 1999, CISS refers to the preference for a chiral molecule or chiral material to preferentially transmit electrons of one spin orientation over that of the other. This spin-filtering of electron currents has important implications for electron transfer and electrochemical processes. In addition to spin-filtered currents, charge displacement currents in chiral molecules are spin-polarized, and this has important implications for enantioselective intermolecular interactions.
The Waldeck Lab is currently accepting new graduate students.
Chiral Nanomaterials
The Waldeck group is exploring design features of chiral symmetry that promote the efficient flow of electron charge and electron spin in nanoparticle-based materials which form by self-assembly. Chiral molecules and nanostructures manifest unusual electronic and magnetic properties; for example, chiral materials are able to filter electron spins. These recent findings establish new opportunities across a range of applications in optically coupled electronic devices, electronic devices whose function is derived from the spin of electrons, and devices that are important in quantum information science. The Waldeck group is elucidating how a chiral nanostructured material’s architecture and optical properties may be designed to promote efficient charge and spin transport - properties that are essential for developing efficient energy conversion and optoelectronic devices.
Electrochemistry
Waldeck’s group explores the use of spin-polarized electrons to improve the chemical selectivity, and energy efficiency, in electrocatalysis. By building on ideas from the CISS effect, they are developing new electrode materials and electrode designs for generating spin polarized electrons and evaluating their performance as electrocatalysts. The idea that chiral catalysts and chiral electrodes can be used to generate spin polarized electron currents which can then be used to promote particular chemical reaction pathways represents a fundamentally new approach for electrocatalysis and electrosynthesis. Their recent work on the oxygen evolution reaction, which is critically important for energy technologies, shows that chiral electrocatalysts can be used to improve the faradaic efficiency of electrochemical reactions that involve the generation of high spin products, i.e., triplet oxygen.
Enantioselectivity and Homochirality
The Waldeck group is exploring how the homochirality of biological molecules (oligopeptides, proteins, and nucleic acids) and of molecular assemblies affect electron transfer, enantioselective molecular recognition, and biological allostery. Conventional wisdom considers that enantiospecific interactions between molecules is dominated by stereoisomeric effects, however recent work shows that spin polarization of chiral molecules can be comparable to stereoisomeric effects. Moreover, protein voltammetry studies show that electron transfer through homochiral assemblies is more efficient than that through heterochiral assemblies. Given the ubiquitous homochirality of living organisms, the connection between the electron spin and chirality holds important implications for biochemical and biological processes.
Awards
- Fellow of the American Chemical Society, 2020
- ISE Bioelectrochemistry Prize, 2018
- American Association for the Advancement of Science Fellow, 2017
- ACS-WCC Award for Encouraging Women in Chemistry 2016
- ACS Pittsburgh Award 2014
- Fellow of the American Physical Society, 2005
- Belkin Visiting Professor, Weizmann Institute 1998 - 1999
- Chancellor's Distinguished Research Award, University of Pittsburgh, 1994