visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
장소 E6-2. 1st fl. #1323 
일시 Apr. 28 (Fri.), 02:30 PM 
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 일시 장소 연사 제목
공지 2019/09/18 - 12/5  Seminar Room #1323  Prof. David Schuster and etc.  Fall 2019: Physics Seminar Serises
공지 2019/09/02 - 12/09  Seminar Room 1501  이호성 박사 (한국표준과학연구원) and etc.  Fall 2019: Physics Colloquium
217 2015/09/07, 3PM  E6-2. 1st fl. #1318  Dr. Jasbinder Sanghera (U.S. Naval Research Laboratory (NRL))  Advanced Optical Materials and Devices at NRL
216 Apr. 12 (Tue.), 4 PM  E6-2. 1st fl. #1323  Dr. Jeehoon Kim, POSTECH  Confinement of Superconducting Vortices in Magnetic Force Microscopy
» Apr. 28 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. JeongYoung Park Graduate School of EEWS, KAIST  Hot electron generation at surfaces and its impact to catalysis and renewable energy conversion
214 2015/12/11, 3:45PM  E6-2, #1323  Dr. Ji Hun Sim (POSTECH)  Dynamical mean field theory studies on heavy fermion system
213 Apr.19 (Fri.), 11:00 AM  #1323, E6-2  Dr. Ji-Sang Park  First-principles studies of semiconductors for solar cell applications file
212 Sep. 27 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. Jindong Song  0D/1D/2D/3D III-V materials grown by MBE for Optelectronics file
211 Mar. 16 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. JinHee Kim  산화물 다층박막에서의 다양한 물리현상 file
210 Dec. 8(Thu) 4p.m.  #1323(E6-2. 1st fl.)  Dr. Jinhyoung Lee, Hanyang University  Dynamical Resonance between Two Optical Cavities via Optomechanical Oscillator
209 Mar. 2nd (Thu), 4:00 p.m  #1323(E6-2. 1st fl.)  Dr. Jonathan Denlinger, Lawrence Berkeley National Lab  “Progress in the comparison of ARPES to DMFT for d and f strongly correlated electron systems”
208 Apr. 01 (Fri.) 4:15 PM  E6-2. 1st fl. #1501  Dr. JONG SOO LIM, KIAS  Cotunneling drag effect in Coulomb-coupled quantum dots
207 2015/08/03,10:30AM  E6-2, #1323 (Seminar Room)  Dr. Jonghee Yoo (Fermi National Accelerator Laboratory, USA )  Axion Search
206 Nov. 04 (Fri), 1:30 PM  E6-2. #1323(1st fl.)  Dr. Jonghyun Song, Department of Physics, Chungnam National University  Exotic phenomena at oxide LaAlO3/SrTiO3 hetero-interface and their applications
205 October 19 (Fri.), 10:00 AM  #1323, E6-2  Dr. Jongsoo Yoo  Energy conversion processes during magnetic reconnection in a laboratory plasma file
204 Dec. 7 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. Joon Ho Jang  Novel probes of interacting electrons in 2D systems file
203 Sep. 27 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. Joon Sue Lee  Spin-charge conversion in topological insulators for spintronic applications file
202 Nov. 1 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. Ju-Jin Kim  Electron transport through weak-bonded contact metal with low dimensional nano-material file
201 July. 14 (Fri.), 3:00 PM  #1323 (E6-2. 1st fl.)  Dr. Jun Hyun Lee / University of Maryland  Chiral anomaly in disordered Weyl semimetals file
200 June 27 (Wed.), 13:30 PM  #1323, E6-2  Dr. Jung Sik Park  Magnetic reversal of artificial spin ice file
199 2015/12/17, 11:00AM  E4(KI Building), Matrix Hall (2nd fl.)  Dr. Jung-Hoon Park (Purdue University)  Wavefront engineering for in-vivo Deep brain imaging
198 Oct. 18 (Tue.), 3PM  E6-2. 1st fl. #1323  Dr. JunHo Suh, Korea Research Institute of Standards and Science  “Hybrid quantum systems with mechanical oscillators”