Presenter: Dr. Wei Sun (University of Toronto)
Topic: Synthesis and Surface Reactions of Hydride Terminated Silicon Nanocrystals with Strong Quantum Size Effect
Time: 02:00 PM, Oct. 17th (Monday)
Location: Conference Room B, BLDG 909-1F
Silicon nanocrystals (ncSi) are drawing increasing attention because of their earth-abundance, low cost, and purported lack of toxicity. To synthesize freestanding ncSi, we employed several methods that could all yield hydride-terminated ncSi. A high yield synthesis was developed that produced polydispersions of decyl-capped, hexane-soluble ncSi predominantly with NIR photoluminescence. Using size-selective precipitation, these polydispersions were separated into monodisperse fractions, which allowed their photoluminescence absolute quantum yield to be studied as a function of ncSi size. Finally, we describe the unprecedented observation that ncSi:H can function as a single component heterogeneous reducing agent for converting gaseous CO2 selectively to CO. This work presented provides opportunities for applications of size-selected near infrared emitting ncSi in biomedical imaging, photothermal therapy, and CO2 reduction for the production of chemicals and fuels.
Dr. Wei Sun received his B.S. degree in chemistry from Jilin University in 2010, and worked as student researcher at the State Key Lab of Supramolecular Structure and Materials under the supervision of Prof. Bai Yang. Recently obtained his doctoral degree from the chemistry department at University of Toronto working with Prof. Geoffrey Ozin. His research interest is in functional nanomaterials, specifically related to silicon and germanium nanostructures. He has published more than 10 scientific articles, including in Nature Communications, Adv. Mater., JACS and Adv. Funct. Mater. He has received a number of awards including Chinese Government Award for Outstanding Self-Financed Students Abroad and Connaught Scholarship.
Contact: Prof. Le He