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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
240 Nov. 24(Thu) 4p.m.  #1323(E6-2. 1st fl.)  Dr. Jai-Min Choi, Chonbuk National Univiersity  Harmonic oscillator physics with single atoms in a state-selective optical potential
239 Nov. 29(Tue) 4p.m.  #1323(E6-2. 1st fl.)  Dr. SungBin Lee, KAIST  Symmetry Protected Kondo Metals and Their Phase Transitions
238 Dec. 8(Thu) 4p.m.  #1323(E6-2. 1st fl.)  Dr. Jinhyoung Lee, Hanyang University  Dynamical Resonance between Two Optical Cavities via Optomechanical Oscillator
237 Dec. 9(Fri), 1:30 p.m.  #1323(E6-2. 1st fl.)  Dr. Jae Yoon Cho, POSTECH  Entanglement area law in strongly-correlated systems
236 Feb. 1 (Wed.), 2p.m.  #1323(E6-2. 1st fl.)  Dr. Michihisa Yamamoto, Department of Applied Physics, The University of Tokyo  Quantum electron optics using flying electrons
235 October 18 (Thu.), 16:00 PM  #1323, E6-2  Prof. Jongseok Lee  Applications of nonlinear optics for condensed matter researches file
234 October 4 (Thu.), 16:00 PM  #1323, E6-2  Prof. Soo Jin Kim  Engineering light absorption in an ultrathin semiconductor metafilm file
233 October 11 (Thu.), 16:00 PM  #1323, E6-2  Prof. Joung-Real Ahn  Dirac electrons in a graphene quasicrystal file
232 October 15 (Mon.), 16:00 PM  #1323, E6-2  Dr. Yongjoo Baek  Universal properties of macroscopic current-carrying systems file
231 October 16 (Tue.), 10:00 AM  #1323, E6-2  Dr. Won-Ki Cho  Capturing protein cluster dynamics and gene expression output in live cells file
230 October 18 (Thu.), 10:00 AM  #1323, E6-2  Dr. Duyoung Min  Understanding membrane protein folding using single-molecule force techniques file
229 October 19 (Fri.), 10:00 AM  #1323, E6-2  Dr. Jongsoo Yoo  Energy conversion processes during magnetic reconnection in a laboratory plasma file
228 September 5 (Wed.), 16:00 PM  #1323, E6-2  Dr. Dirk Wulferding  Shining a light on fractional excitations file
227 September 20 (Thu.), 16:00  #1323, E6-2  Prof. Joo-Hiuk Son  Toward Cancer Treatment Using Terahertz Radiation: Demethylation of Cancer DNA file
226 June 27 (Wed.), 13:30 PM  #1323, E6-2  Dr. Jung Sik Park  Magnetic reversal of artificial spin ice file
225 May 9 (Wed.), 04:00 PM  #1323, E6-2  Prof. Jong-Soo Rhyee  Recent advances in thermoelectric bulk composites file
224 May 29 (Tue.), 04:00 PM  #1323, E6-2  Prof. Jae-Won Jang  Investigation on metal nanostructure/semiconductor junction and its applications file
223 May 311 (Thu.), 04:00 PM  #1323, E6-2  Prof. Teun-Teun Kim  Dynamic control of optical properties with gated-graphene metamaterials file
222 June 22 (Fri.), 04:00 PM  #1323, E6-2  Dr. Daniel Sando  Tuning functional properties of BiFeO3 films using strain and growth chemistry file