visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2017-04-28 14:30 
일시 Apr. 28 (Fri.), 02:30 PM 
장소 E6-2. 1st fl. #1323 
연사 Dr. JeongYoung Park Graduate School of EEWS, KAIST 

 

Hot electron generation at surfaces and its impact to catalysis and renewable energy conversion

 

Dr. JeongYoung Park

Graduate School of EEWS, KAIST

Apr. 28 (Fri.), 02:30 PM

E6-2. 1st fl. #1323

 

 

Abstract: 

A pulse of high kinetic energy electrons (1–3 eV) in metals can be generated after surface exposure to external energy, such as the absorption of light or exothermic chemical processes. These energetic electrons are not at thermal equilibrium with the metal atoms and are called ‘‘hot electrons’’. The detection of hot electrons and understanding the correlation between hot electron generation and surface phenomena are challenging questions in the surface science and catalysis community. Hot electron flow generated on a gold thin film by photon absorption (or internal photoemission) appears to be correlated with localized surface plasmon resonance. 

In this talk, I will show strategy to quantify the non-adiabatic energy transfer and detect hot electron flux during the elementary steps of the energy conversion process and catalytic reaction processes occurring at both of solid-gas and solid-liquid interfaces. To detect and utilize the hot electron flows, the nanodiodes consisting of metal catalyst film, semiconductor layers, and Ohmic contact pads were constructed It was shown that the chemicurrent or hot electron flows were well correlated with the turnover rate of CO oxidation or hydrogen oxidation separately measured by gas chromatography, suggesting the intrinsic relation between catalytic reaction and hot electron generation. We show a novel scheme of graphene catalytic nanodiode composed of a Pt NPs array on graphene/TiO2 Schottky nanodiode, which allows detection of hot electron flows induced by hydrogen oxidation on Pt NPs. By analyzing the correlation between the turnover rate (catalytic activity) and hot electron current (chemicurrent) measured on the graphene catalytic nanodiodes, we demonstrate that the catalytic nanodiodes utilizing a single graphene layer for electrical connection of Pt NPs are beneficial for the detection of hot electrons due to not only atomically thin nature of graphene but also reducing the height of the potential barrier existing at the Pt NPs/graphene interface. I will show that hot electron flow generated on a gold thin film by photon absorption (or internal photoemission) is amplified by localized surface plasmon resonance. Finally, The effect of surface plasmons on the catalytic and photocatalytic activity on metal–oxide hybrid nanocatalysts is also highlighted. These phenomena imply the efficient energy conversion from the photon energy to the chemical energy, with the potential application of hot electron-based photocatalytic devices.

 

 

 

번호 날짜 장소 제목
226 2018-07-27 13:30  #1323, E6-2  Magnetic reversal of artificial spin ice file
225 2019-06-28 13:30  #1323, E6-2  Magnetic domains and domain wall conduction in pyrochlore iridate thin films and heterostructures file
224 2022-06-03 11:00  E6-2 #1323  (응집물리 세미나) Theoretical Investigation of Exotic Quantum States in Low-dimensional Materials
223 2023-06-30 11:00  E6-6 #1501  The Dual Mode Quantum Computer file
222 2022-06-03 09:30  Online seminar  (Quantum-&Nano-Photonics Webinar) Seeing glass in a new light: reimagine chalcogenide photonics file
221 2019-06-04 17:00  #1323, E6-2  Stochastic nature of bacterial eradication using antibiotics file
220 2023-06-08 16:00  E6-2, #1323  Thermal decoupling in high-Tc cuprate superconductors
219 2024-03-28 11:00  E6, #2501  Geometric characterization of thermoelectric performance of two-dimensional quadratic band-crossing semimetals
218 2021-03-02 16:00  Online  Sensitive terahertz detection with graphene-based transistors file
217 2023-03-22 16:00  E6-2, #2502  (High Energy Theory Seminar) Boltzmann or Bogoliubov? A Case of Gravitational Particle Production
216 2024-03-27 16:00  E6-2, #2502  [High Energy Theory Seminar] The Callan Rubakov Effect
215 2023-03-02 11:00  E6-2, #1322  Probing Anomalies of Non-Invertible Symmetries with Symmetry TFTs
214 2024-03-13 16:00  E6-2 #2502  [High-Energy Theory Seminar] The Schwarzschild Black Hole from Perturbation Theory to all Orders
213 2018-03-16 14:30  E6-2. 1st fl. #1323  산화물 다층박막에서의 다양한 물리현상 file
212 2018-03-16 14:30  E6-2. 1st fl. #1323  산화물 다층박막에서의 다양한 물리현상 file
211 2018-03-16 16:00  E6-2. 1st fl. #1323  Van der Waals Heterostructures from Quantum Transport to Ultrafast Optoelectronics file
210 2018-03-16 16:00  E6-2. 1st fl. #1323  Van der Waals Heterostructures from Quantum Transport to Ultrafast Optoelectronics file
209 2023-03-16 16:00  E6-2 #1323  (광학분야 세미나) Investigation of 3D cell mechanics using refractive-index tomography
208 2023-03-17 11:00  E6-2 #1323  (응집물리 세미나)Operando electron microscopy investigation of domain dynamics in twisted van der Waals materials file
207 2024-03-20 16:00  E6-2 #2502  [High-Energy Theory Seminar] Black hole states at finite N