Please note this seminar has been cancelled due to Vanderbilt COVID-19 restrictions. We are working to reschedule.
April 8, 2020
Krishnan Rajeshwar Distinguished University Professor Chemistry and Biochemistry Department University of Texas at Arlington "Fuel from the Sun: Where is that Pot of Gold?"
4:10 PM, 5326 Stevenson Center
Refreshments served at 3:45
Abstract
Even after ca. four decades of R&D effort, we still do not have a “magic bullet” inorganic semiconductor to photoelectrochemically generate fuels or chemicals from sunlight in a sustainable, efficient and environment-friendly manner. While it is unlikely that a single semiconductor candidate will emerge that simultaneously satisfies all the optical, electrical, surface chemical, and electrochemical prerequisites for efficient solar conversion, complex oxides or chalcogenides (or derivatives thereof, e.g., oxynitrides) do provide a versatile framework for rational design of the magic bullet in a chemical architectural sense. Ultimately two or more such semiconductor compositions can be combined in a composite design much like complementary functionalities are combined in photosynthetic assemblies in Nature. In such designs, the semiconductor(s) and the photoactive junction can even be separated from the electrolyte and the electrocatalyst component in a “buried junction” design. In this vein, the author’s laboratory has been engaged in the development of time-efficient methods for synthesizing new libraries of photoelectrode or photocatalyst materials. In this talk, I will provide first a context for the key role that solid-state inorganic chemistry & photochemistry paradigms and principles can play in electrode designs for driving multi-electron processes typical of solar fuel generation. Representative ternary or quaternary semiconductor systems, including, Cu-V-O, Ag-V-O and M-Ln-X (M = divalent metal, e.g., Ba, Ln = lanthanide element, e.g., La, Ce, and X = chalcogen, e.g., S) will be discussed in this talk. Finally, some perspectives will be offered for the challenges and possibilities.
Bio
Dr. Rajeshwar is a Distinguished University Professor at the University of Texas at Arlington. He is also the founding director of the Center for Renewable Energy Science & Technology (CREST) on campus. He was elected Vice President of the Electrochemical Society (ECS) and is now a past President of the ECS. He is a past Editor of the ECS Interface and currently serves on the editorial boards of several electrochemical journals. He is currently the Editor-in-Chief of the ECS Journal of Solid-State Sci. & Technol. After post-doctoral training at Colorado State University, he joined UT Arlington in 1983. His research interests span a wide spectrum and include photoelectrochemistry; solar energy conversion; renewable energy; materials chemistry; semiconductor electrochemistry; and environmental chemistry. Dr. Rajeshwar is a Fellow of the Electrochemical Society and received the Energy Technology Division Research Award of the Electrochemical Society in 2009. He will receive the Research Award of the Electrodeposition Division at the upcoming fall meeting of the ECS in Atlanta, GA. He has authored monographs and edited books, special issues of journals, and conference proceedings on energy conversion. He is the author of over 400 peer-reviewed and well-cited publications (cited over 20,000 times, h-index: 66) and can be reached at rajeshwar@uta.edu.