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
306 2019-06-04 17:00  #1323, E6-2  Stochastic nature of bacterial eradication using antibiotics file
305 2022-06-03 09:30  Online seminar  (Quantum-&Nano-Photonics Webinar) Seeing glass in a new light: reimagine chalcogenide photonics file
304 2023-06-30 11:00  E6-6 #1501  The Dual Mode Quantum Computer file
303 2022-06-03 11:00  E6-2 #1323  (응집물리 세미나) Theoretical Investigation of Exotic Quantum States in Low-dimensional Materials
302 2019-06-28 13:30  #1323, E6-2  Magnetic domains and domain wall conduction in pyrochlore iridate thin films and heterostructures file
301 2018-07-27 13:30  #1323, E6-2  Magnetic reversal of artificial spin ice file
300 2018-07-27 13:30  #1323, E6-2  Magnetic reversal of artificial spin ice file
299 2019-06-27 14:00  #2502, E6-2  Gapless Kitaev Spin Liquid to Loop and String Gases file
298 2023-06-26 11:00  E6, Rm#1323  Quantum computing on magnetic racetracks with flying domain wall qubits
297 2022-06-23 11:00  E6 Room(#1322)  JILA’s search for the electron’s Electric Dipole Moment (eEDM) to probe physics beyond the standard model file
296 2023-06-22 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  [CAPP Seminar] The muon g-2 puzzle file
295 2018-06-22 16:00  #1323, E6-2  Tuning functional properties of BiFeO3 films using strain and growth chemistry file
294 2018-06-22 16:00  #1323, E6-2  Tuning functional properties of BiFeO3 films using strain and growth chemistry file
293 2019-06-17 10:30  #1323, E6-2  Chiral Spintronics file
292 2023-06-16 13:00  E6-2, #2502  Quantum critical states under extreme conditions
291 2023-06-15 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  [CAPP Seminar] Cryogenic electronics for ion traps file
290 2023-06-14 16:00  E6-2, #2502  [High-Energy Theory Seminar]Vertex algebras and extended operators in 4d N=2 SCFTs
289 2016-06-14 15:00  #1323 (E6-2 1st fl.)  No-Insulation High Temperature Superconductor Magnet Technology for Compact, Reliable, and Low-Cost High Field DC Magnets
288 2023-06-14 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  [CAPP seminar] EMC at CERN file
287 2018-06-14 10:00  E6-2, 2nd fl. #2502  Phonons and polariton-like particles in trapped ions for quantum computation and quantum simulation file