Modern Chemistry & Applications

Catalysis using transition metal chalcogenides for energy conversions

Joint Event on 19^th International Conference on Medicinal Chemistry & Multi Targeted Drug Delivery & International Conference on Catalysis and Pyrolysis

November 05-06, 2018 | San Francisco, USA

Hyoyoung Lee

Sungkyunkwan University, Korea

Keynote: Mod Chem Appl

Abstract:

In this seminar, I will discuss an energy conversion using semiconducting catalyst materials. A control of the energy band gap of semiconducting materials including transition metal chalcogenides (TMCs) including TiO2, MoS2 and CoS2 have been paid attention for energy conversion and environmental issues. Herein, we like to introduce new findings of the visiblelight driven blue TiO2 materials for photo-catalytic hydrogen evolving reaction (HER) and for an application to remove algae from water. In addition, we like to report new layered ternary transition metal chalcogenides (TTMCs) material to overcome to the limitation of active sites which is challenging in binary transition metal chalcogenides (BTMC) such as MoS2 towards electrochemical hydrogen production. The TTMC, Cu2MoS4 has been successfully synthesized by a facile solution-processed method. Moreover, by an ion doping such as Se in as the synthesized Cu2MoS4, it has been found that TTMC can be exfoliated into single layer nanosheets and the single-layered TTMC exhibits the highest electrocatalytic activity towards HER. We also report an advanced bi-functional hybrid electrocatalyst for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), which is composed of WS2 and CNT connected via tungsten carbide (WC) bonding. WS2 sheets on the surface of CNTs provide catalytic active sites for electrocatalytic activity while the CNTs act as conduction channels and provide a large surface area. We found that four to five layers of WS2 sheets on the surface of CNTs produces excellent catalytic activity towards both ORR and OER, which is comparable to noble metals (Pt, RuO2, etc.). Finally, we like to demonstrate a new strategy to satisfy all requirements for the development of a highly active and remarkably durable HER electrocatalyst in both acidic and alkaline media via anion-cation double substitution into a CoS2 moiety for preparing 3D mesoporous pyrite-metal vanadiumcobalt phosphorus sulphide (Co1-xVxSP).

Biography :

Hyoyoung Lee has completed his PhD at Department of Chemistry, University of Mississippi, the USA in 1997. He did his Postdoctoral studies at North Carolina State University. He worked at Electronics and Telecommunications Research Institute and then moved to Department of Chemistry, Sungkyunkwan University as a full Professor. He served as a director of National Creative Research Initiatives. Currently, he has served as an Associate Director of the Centre for Integrated Nanostructure Physics, Institute of Basic Science. His current research area is 0-2D semiconducting materials and their devices. He has written more than 140 journal articles in top-tier journals and has been serving as an editorial board member of scientific reports.

E-mail: hyoyoung@skku.edu