Topic: Studies on Photoelectrodes, Catalysts, and Interfaces for Photoelectrochemical Water Splitting

Speaker: Professor Kyoung-Shin Choi - Dept of Chemistry, University of Wisconsin-Madison

Host: Professor Aaron Odom

Date: Tuesday, October 9, 2018

Time: 4:10 PM

Location: 136 CEM

More Information:

Harvesting energy directly from sunlight as nature accomplishes through photosynthesis is a very attractive and desirable way to solve the energy challenge.  Many efforts have been made to find appropriate materials and systems that can utilize solar energy to produce chemical fuels. One of the most viable options is the construction of a photoelectrochemical cell (PEC) that can directly utilize solar energy to drive chemical reactions (e.g. reduction of water to H2). For successful construction of photoelectrochemical cells, simultaneous developments of photoelectrodes, which will efficiently capture photons to generate and separate electron-hole pairs, and catalysts, which will facilitate the use of photogenerated electrons and holes for desired interfacial charge transfer reactions, are necessary. Optimally interfacing photoelectrodes and catalysts is critical because the photoelectrode/catalyst interface can govern the overall efficiency of the integrated photoelectrode system. Furthermore, as the performance of photoelectrodes continues to improve, concurrent improvement of their photostabilities has become another important issue.

In this presentation, we will discuss various strategies to improve photoelectrode performances and photoelectrode/catalyst interfaces using a BiVO4 photoanode as an example.  Also, we will present new insights we gained regarding the photocorrosion process of BiVO4, which resulted in a simple yet effective strategy to enhance the photostability of BiVO4 during water oxidation over 500 hours. The collective discussions on the key factors that govern photocurrent generation and photostability of BiVO4 will provide a good foundation to develop new strategies to improve the performance and photostability of other photoelectrodes for use in PECs for solar fuel production.