visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2017-04-28 14:30 
연사  
장소 E6-2. 1st fl. #1323 

 

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 연사 제목
공지 2025-02-24 16:00    2025년 봄학기 콜로키움 안내
공지 2025-02-27 16:00    2025년 봄 물리학과 특별세미나 (광학/응집물리 분야)
385 2019-04-11 16:00    Massive screening for cathode active materials using deep neural network file
384 2018-09-20 16:00    Toward Cancer Treatment Using Terahertz Radiation: Demethylation of Cancer DNA file
383 2018-09-20 16:00    Toward Cancer Treatment Using Terahertz Radiation: Demethylation of Cancer DNA file
382 2018-10-18 16:00    Applications of nonlinear optics for condensed matter researches file
381 2018-05-09 16:00    Recent advances in thermoelectric bulk composites file
380 2017-01-09 16:00    Topological Defects and Phase Transitions" file
379 2016-07-28 16:00    Low Dimensional Electrons: On the Road to Hybrid Quantum Systems
378 2019-04-23 16:00    From Mott physics to high-temperature superconductivity file
377 2022-07-21 16:00    Quintessential axions file
376 2019-11-14 16:00    Semi-classical model of polariton propagation file
375 2017-12-15 09:20    Workshop on Magnetism in Unconventional Superconductors 개최 file
374 2024-05-01 16:00    [High Energy Theory Seminar] Across the Mass Spectrum: Utilizing Small-Scale Structures to Probe Dark Matters
373 2019-11-07 16:00    Integrated quantum photonics with solid-state quantum emitters file
372 2018-05-29 16:00    Investigation on metal nanostructure/semiconductor junction and its applications file
371 2020-10-23 14:00    Plasmon spectroscopy of low-dimensional superconductors in fluctuating regime file
370 2025-02-25 14:00  Prof. Igor Di Marco  Dynamical mean-field theory for strongly correlated materials file
369 2024-05-16 16:00    [High Energy Theory Seminar] Conformal Collider Physics
368 2018-07-13 14:00    Loop Induced Single Top Partner Production and Decay at the LHC
367 2018-12-11 16:00    Natural compact representation of Matsubara Green’s functions: applications to analytic continuation and quantum many-body simulations file
366 2017-08-31 14:00    “Berry phase and nonlinear response: photocurrent in noncentrosymmetric insulators and Weyl semimetals” file