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McKelvey School of Engineering

Brown School

EECE SEMINAR - Bryce Sadtler

Friday, February 5, 2021 | 11:00 AM - 12:00 PM

Virtual Event

Bryce Sadtler, Assistant Professor, Department of Chemistry, Washington University in St. Louis, will present:  

Nanoscale Imaging of Catalytic Activity in Semiconductor Nanostructure Using Super-Resolution Fluorescence Microscopy

Abstract:
Defect engineering is a strategy that has been widely used to design active semiconductor photocatalysts. However, understanding the role of defects, such as oxygen vacancies, in controlling photocatalytic activity remains a challenge. In this talk I will discuss the use of chemically triggered fluorogenic probes to study the spatial distribution of active regions in individual semiconductor nanostructures using super-resolution fluorescence microscopy. While this technique has been demonstrated as a powerful method to image heterogeneity in the reactivity of nano- and microstructured catalyst particles, a major challenge of applying single-molecule fluorescence to heterogeneous catalysis is that the spatial resolution it provides (typically 10 to 25 nm) still averages over many atoms across the surface of the catalyst. To overcome this limitation, we have developed in collaboration with Matthew Lew in ESE a quantitative method for the spatial colocalization of multiple chemical probes to elucidate the nature of active sites in nanostructured catalysts. The idea is that a limited number of surface features (in this case oxygen vacancies) are capable of catalyzing two orthogonal reactions (e.g., one photocatalytic and one acid-catalyzed). In one example of applying this two-color imaging of catalytic events, we have demonstrated that the distribution of oxygen vacancies is non-uniform in tungsten oxide nanowires. Clusters of oxygen vacancies activate surface-adsorbed water molecules towards photooxidation to produce hydroxyl radicals, a critical intermediate in the photocatalytic oxidation of water, methane, and environmental pollutants.
 

Event Type

Seminar/Colloquia

Schools

McKelvey School of Engineering

Topic

Science & Technology

Website

https://eece.wustl.edu/news-events/se...

Department
Energy, Environmental & Chemical Engineering
Hashtag

##seminar

Event Contact

Kim Coleman; kcole@wustl.edu

Speaker Information

Dr. Bryce Sadtler
Assistant Professor
Department of Chemistry
Washington University in St. Louis

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