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Pr. Jyh-Chiang Jiang

Department of Chemical Engineering, National Taiwan University of Science and Technology, Taiwan

 

Talk Title
First Principles Studies for Efficient Energy Conversion and Storage

Talk Abstract
 

In the 21st century, Dye-sensitized solar cells (DSSCs) have been considered as an alternative to the conventional silicon-based devices in the generation of energy. The overall photovoltaic performance of DSSCs depends on many factors, such as molecular design of the dyes, dye adsorption characteristics on the semiconductor surface and dye regeneration mechanism. Thus, we aimed to improve the efficiency by considering the above factors using state of the art theoretical tools.  In designing efficient sensitizer, we have proposed a design strategy and identified the suitable electron donors and acceptors and its effects on overall optoelectronic properties. In addition, finding an ideal adsorption configuration for a dye on the semiconductor surface is an important task. We also investigated the different adsorption configurations of designed model dyes on TiO2 anatase (101) surface. We also proposed a new regeneration mechanism for organic dyes by assuming the probability of two-electron injection from the stable dye-iodide intermediate complex and reported their UV-vis absorption spectra.

Besides, hydrogen has been concerned as clean energy carrier among the other renewable energy sources because of its environmental friendliness. However, some challenges have to be addressed before hydrogen will become a conventional and commonly available energy carrier. Carbon-based materials such as graphene and carbon nanotubes have been designed for hydrogen storage due to their large surface area, lightweight, and tunable properties. Recently, we proposed a new strategy in which we considered three pure transition metal (TM) atoms or/and a combination of two TM atoms and one alkali earth metal atom (AEM) with high, medium and low hydrogen adsorption energies. These different metal atoms are used to decorate the Boron doped graphene sheet (BDG) and investigated their performance towards hydrogen storage capacity through spillover mechanism using first-principles calculations. Our results indicate that that the activation energies for H atom diffusion are much smaller, indicating that a fast H diffusion on this proposed surface can be achieved.  These TM and AEM atoms decorated BDG surface can have the maximum hydrogen gravimetric capacity of 6.4% for double-sided adsorptions. To achieve higher gravimetric density, we also considered the Boron and Nitrogen co-doped graphene surface (BNDG) because B–N pair is isoelectronic to the C–C pair. The designed medium will be a good candidate for the efficient Hydrogen storage at ambient conditions.

Short Biography

Dr. Jyh-Chiang Jiang is a Professor in Department of Chemical Engineering, National Taiwan University of Science & Technology, Taiwan.  Currently, has worked extensively in the development of combined electronic structure and kinetics methods for simulating processes that involve the reaction mechanisms of H2 production, Hydrogen storage, NH3 oxidation on metal oxide surface. Dr. Jiang is also involved in High throughput screening of many new materials for Li ion batteries based on quantum mechanics calculation. In addition, he has been active for many years in design of the optoelectronic materials for DSSCs using quantum mechanics simulation. He has more than 160 papers in peer-reviewed journals. His research has also resulted in 4 patents.

 
Talk Keywords
Dye-sensitized solar cells, Dyes, UV/Vis spectra, Hydrogen Storage, Graphene.
 
Target Audience
Students, Post doctoral, Industry, Doctors and professors
 
Speaker-intro video
TBA 
 

The International Conference on Innovative Applied Energy (IAPE’18)