Speaker: Vincent Tung
Affiliation: University of California-Merced
Dr. Vincent Tung
School of Engineering, University of California, Merced
Electrohydrodynamic-assisted Crumpling of MoS2 for Highly Efficient Hydrogen Evolution Reaction
Recent interest in reconfiguring the global energy infrastructure away from fossil fuels and toward carbon-neutral energy has continuously propelled the resurging research interest in Hydrogen Evolution Reaction (HER). While platinum (Pt) remains the current benchmark for HER, the elemental scarcity, high cost and poor stability against nanoparticle coarsening and agglomeration impose practical limitations. To qualify as a viable alternative to Pt, the catalyst must simultaneously fulfill the following essential factors, (a) high total electrode activities, e.g., overpotentials, Tafel slope, cathodic and exchange current densities at a low geometric mass loading, (b) tailored intrinsic activity, e.g., turnover frequency (TOF), (c) structural integrity and (d) scalability and easy to integrate process. The rise of 2-dimensional (2D) molybdenum disulfide (MoS2) offers intriguing possibilities for realization of a transformative new catalyst capable of replacing Pt for driving the HER in next generation energy conversion devices. Harnessing the outstanding catalytic properties of 2D MoS2 requires the exposure of catalytically active edges, and activation of its inert basal plane while maintaining its single-layered-form, structural integrity, and scalability. In this talk, I will discuss our recent discovery on the first stimuli-induced dimensional transition enabled by a template-free, high throughput electrohydrodynamic approach, that synergistically isolates and transforms 2D chemically-exfoliated-MoS2 (ce-MoS2) to 3D crumpled nanostructures (c-MoS2). Specifically, the combination of highly accessible surface area emanating from hierarchically porous morphology, internal edges, and sulfur (S) vacancies intrinsic to ce-MoS2 coupled with localized conformational strain at both atomic- and nano-scales via self-crumpling allows us to simultaneously achieve state-of-art total electrode and intrinsic activities among MoS2-based catalysts while using a fully scalable processing route.
Vincent Tung is an Assistant Professor at the School of Engineering, University of California, Merced. He received his Ph.D. degree in materials science and chemistry from the University of California, Los Angeles in 2009 with honor and became an Initiative for Sustainability and Energy at Northwestern (ISEN) postdoctoral research fellow at the Northwestern University in 2010. His main research interest is in the general area of material chemistry and assembly for energy harvesting and storage. He is the recipient of an America Chemical Society Petroleum Fund New Doctoral Investigator Award, and the Research Excellence Early Career Investigator Award by the Graduate Council at the University of California. He is also a die-hard fan of Red Sox and enjoys a cup of coffee at Blue Bottle and Sight glass.
Date(s) - Apr 07, 2017
10:30 am - 12:00 pm