Série přednášek prof. Kamata
Invitation to the series of lectures
Prof. Prashant V. Kamat
(John A Zahm Professor of Science), email:pkamat@nd.edu
Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana, USA
Prashant V. Kamat is a Rev. John A. Zahm, C.S.C., Professor of Science in the Department of Chemistry and Biochemistry and Radiation Laboratory at the University of Notre Dame. He is also a Concurrent Professor in the Department of Chemical and Biomolecular Engineering. Professor Kamat has for more than three decades worked to build bridges between physical chemistry and material science to develop advanced nanomaterials that promise cleaner and more efficient light energy conversion. He has published more than 500 scientific papers that have been well recognized by the scientific community (85000 citations, h-index 146 –Source Web of Science). Thomson-Reuters has featured him as one of the most cited researchers each year since 2014 (2014 -2023). He is a Fellow of ACS, ECS, MRS and AAAS. He is also Pravasi Fellow of the Indian National Science Academy. He is currently serving as the Editor-in-Chief of ACS Energy Letters.
Lecture room: University of Chemistry and Technology Prague, building A, Uhelna – ground floor.
Thursday, 19th September 2024
13.00: Light energy conversion with semiconductor nanostructures, from fundamentals to applications
14.30: Harvesting light energy with perovskite nanocrystals. Energy versus Electron transfer
Friday, 20th September 2024
10.00: Electrocatalytic and photocatalytic processes for energy applications
11.00: Informal discussion with students and researchers– two topics
- How to make your next paper even more effective
- How ChatGPT is changing the scientific publication
Light energy conversion with semiconductor nanostructures, from fundamentals to applications
Prashant V. Kamat
Department of Chemistry and Biochemistry and Radiation Laboratory, University of Notre Dame, Notre Dame, IN46556, USA
Semiconductor nanostructures are finding new ways to design light energy conversion devices (e.g., thin film solar cells and light emitting devices). The decreased consumption of energy during the manufacture and the lessened use of semiconductor materials lowers the overall carbon footprint with energy payback time less than a year for such devices. The early studies focused on the synthesis of various semiconductor nanostructures and exploration of their size dependent optical and electronic properties. Careful engineering efforts in recent years have led to their integration in high efficiency thin film solar cells. Metal halide perovskite solar cells, in particular can now deliver efficiencies greater than 26%, thus matching the power conversion efficiency of silicon solar cells. In addition, semiconductor nanostructure-based assemblies also provide new ways to generate solar fuels (e.g., H2 generation). Unlike solar cell devices, photocatalytic processes are yet to deliver conversion efficiencies and stability that can make them compatible for practical applications. Understanding the limitations imposed by interfacial charge transfer processes remains a key to further advance photocatalytic systems for chemical energy storage. Recent developments in utilizing semiconductor nanostructures for light energy conversion and storage will be discussed.
Harvesting light energy with perovskite nanocrystals. Energy versus Electron transfer
Prashant V. Kamat
Department of Chemistry and Biochemistry and Radiation Laboratory, University of Notre Dame, Notre Dame, IN46556, USA
Surface interaction of chromophore or redox active molecule which dictate the efficiency of energy/electron transfer, plays an important role in realizing photocatalytic and optoelectronic applications. Metal halide perovskite nanocrystals are interesting in the sense that they can either transfer energy or selectively transfer electrons or holes to the adsorbed molecules.1,2 The presentation will focus on two specific scenarios of the flow of energy and electron processes in CsPbX3 (X= Br, I) nanocrystal-molecular hybrids. The energy transfer is probed through three moleculr acceptors – rhodamine B (RhB), rhodamine isothiocyanate (RhB-NCS), and rose Bengal (RoseB), which contain an increasing degree of heavy atom pendant groups. Electron and/or hole transfer from excited CsPbX3 nanocrystals to a molecular relay present near the interface offers another avenue to directly convert light energy into chemical energy. Such interfacial electron transfer of semiconductor nanocrystals has been widely explored in photocatalytic processes. A basic understanding of the fundamental differences between the two excited deactivation processes (energy and charge transfer) and ways to modulate them should enable design of more efficient light harvesting assemblies with semiconductor and molecular systems.
References:
Electrocatalytic and photocatalytic processes for energy applications
Prashant V. Kamat*
Department of Chemistry and Biochemistry and Radiation Laboratory, University of Notre Dame, Notre Dame, IN46556, USA
In recent years new opportunities have emerged in photocatalytic and electrocatalytic hydrogen evolution and CO2 reduction. Design of new photocatalysts and electrocatalysts offer new opportunities to tackle the energy and environmental issues. The talk will focus on identifying new opportunities in electrocatalytic and photocatalytic applications for energy conversion processes. Artifacts encountered while conducting these experiments will also be discussed. Some of these artifacts include contribution of sacrificial donor oxidation to overall products,1,2 photocatalyst degradation/transformation,3,4 impurity effects,5 counter electrode reactions6 etc. Ways to assess the merits of photocatalytic experiments and establish the right reaction mechanism will be discussed.
References:
2.Kamat, P. V.; Jin, S. ACS Energy Lett. 2018, 3, 622-623.
3. Jin, S. Are Metal Chalcogenides, ACS Energy Lett. 2017, 2, 1937-1938.
