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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
230 Oct. 17th (Mon) 11:00 AM  #1323,(E6-2, 1st fl.)  Nguyen Quang Liem, Institute of Materials Science, VAST, Viettnam  IMS and examples of the studies on optoelectronic materials
229 Oct. 12 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. HyungWoo Lee  Direct observation of a two-dimensional hole gas at oxide interfaces file
228 Oct. 12 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. Daniel Kyungdeock Park  Quantum Advantage in Learning Parity with Noise file
227 Oct. 10(Tue) 4PM  E6-2 #1323  김성웅 교수 (성균관대학교 에너지과학과)  Discovery of New 2D Materials with Diverse Physical Properties
226 Oct. 07 (Fri), 4:00 PM  E6-2. #1323(1st fl.)  Dr. Choong Hyun Kim,IBS-CCES, Seoul National University  “Tilt engineering of 4d and 5d transition metal oxides?”
225 Oct. 07 (Fri), 1:30 PM  E6-2. #1323(1st fl.)  Dr. Suk Bum Chung, IBS-CCES , Seoul National University  “Symmetry and topology in transition metal dichalcogenide?”
224 November 8 (Thu.), 16:00 PM  #1323, E6-2  이종완 박사  Conformality lost file
223 November 29 (Thu.), 16:00 PM  #1323, E6-2  Dr. Kee suk Hong  양자 칸델라 실현을 위한 단일 광자 발생장치 개발 file
222 November 21 (Wed.), 15:00 PM  #1323, E6-2  Prof. Seongshik Oh  Engineering topological quantum physics at the atomic scale file
221 November 1 (Thu.), 16:00 PM  #1323, E6-2  Dr. KyeoReh Lee  Direct holography from a single snapshot file
220 Nov. 9 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. Donghun Lee  Quantum sensing and imaging with diamond defect centers for nano-scale spin physics file
219 Nov. 9 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. Pilkyung Moon  Moiré superlattices – from twisted bilayer graphene to quasicrystal file
218 Nov. 8 (Wed.), 1:00 PM  #5318 (E6-2. 5th fl.)  Prof. Y. Matsuda Department of Physics, Kyoto University  “Emergent exotic quasiparticles in quantum spin liquids” file
217 Nov. 3 (Fri.), 4:00 PM  #1323 (1st fl., E6-2.)  Dr. SungDae Ji (Max Planck POSTECH/Hshinchu Center (MPK))  Expedition to the Kitaev Quantum Spin Liquid: Hunting for Majorana fermions file
216 Nov. 3 (Fri.), 2:30 PM  #1323 (1st fl., E6-2.)  Dr. MinChul Lee(Department of Applied Physics, Kyung Hee Univ.)  Quantum Resistor-Capacitor Circuit with Majorana Edge States file
215 Nov. 29(Tue) 4p.m.  #1323(E6-2. 1st fl.)  Dr. SungBin Lee, KAIST  Symmetry Protected Kondo Metals and Their Phase Transitions
214 Nov. 28 (Tue.), 4:00 PM  #1323 (E6-2. 1st fl.)  Samindranath Mitra, Editor at Physical Review Letters  Physics after the lab and the desk: Your work in PRL file
213 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
212 NOV. 23 (Fri), 03:00 PM  E6-2. 2st fl. #2501  Prof. Sang-Jin Sin  Entanglement string and Spin Liquid with Holographic duality file
211 Nov. 22th (Thur), 15:00  E6 Room(#1323)  Prof. Suprijadi Haryono  Experimental and Computational Study on Physical Properties based on Granular System file