Time: July 10, 2017, 10:00 am
Venue: Conference Room on the First Floor, Basic Energy Building
Lecturer: Prof. CHEN Peng, Cornell University
I will present two stories that use single-molecule fluorescence imaging to interrogate the catalysis and photoelectrocatalysis of nanoscale particles. In the first story, I will present our work in using single-molecule fluorescence microscopy to study the catalytic properties of individual metal nanoparticles at single-turnover resolution and nanometer precision. I will describe the insights we gained into the catalytic activity and dynamics of individual metal nanoparticles, and the surprising spatial reactivity patterns within single facets at the nanoscale. In the second story, I will present our work in using redox-selective super-resolution reaction imaging and sub-particle photocurrent measurements to determine the relation between charge-carrier surface activity and water oxidation efficiency on a semiconductor photoanode during photoelectrochemical water oxidation. We determine that on a semiconductor nanostructure, how much the sites reactive for water oxidation also contribute to recombination, and how the photocurrent efficiency and onset potential are correlated at the nanoscale. Guided by hole and electron reactivity maps, site-selective catalyst deposition on individual nanorods reveals the optimal sites for oxygen evolution catalysts, leading to a strategy for rationally engineering photoelectrodes with catalysts.
Peng Chen is the Peter Debye Professor of Chemistry at Cornell University. He received his B.S. in Chemistry from Nanjing University, China in 1997. After a year at University of California, San Diego with Prof. Yitzhak Tor learning organic synthesis, he moved to Stanford University and did his Ph.D. with Prof. Edward Solomon in bioinorganic/physical inorganic chemistry. In January 2004, he joined Prof. Sunney Xie’s group at Harvard University for postdoctoral research in single-molecule biophysics. He started his faculty appointment at Cornell University in July 2005. His current research focuses on single-molecule imaging of nanoscale (photo)(electro)catalysis, as well as of metal homeostatic machineries in vitro and in living cells. He has received Dreyfus New Faculty Award, NSF Career Award, Sloan Fellowship, Paul Saltman Award, CAPA Distinguished Junior Faculty Award, Coblentz Award, ACS Phys Division Early-Career Award in Experimental Physical Chemistry, and Excellence in Catalysis Award from the Catalysis Society of Metro NY, etc.
Contact: MAO Jia, Group 505