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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 2017/09/14 - 12/07  Seminar Room #1323  Prof. 정광용 교수(Gacheon Univ) and etc.  Fall 2017: Physics Seminar Serises
공지 2017/09/04 - 12/04  Seminar Room 1501  Prof. Sangsu Bae(Hanyang Univ.) and etc.  Fall 2017: Physics Colloquium
141 Sep. 22 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. GilHo Lee / Department of Physics, POSTECH  Unexpected Electron-Pairing in Integer Quantum Hall Effect file
140 Sep. 22 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. GilHo Lee / Department of Physics, POSTECH  Quantum Electronic Transport in Graphene Hybrid Nanostructures file
139 Sep. 22 (Fri.), 01:00 PM  E6-2. 1st fl. #1323  Dr. EunSeong Kim / Department of Physics, KAIST  Superconductor-metal-insulator transition in thin Tantalum films file
138 Sep. 26 (Tue.), 11AM  #1323 (E6-2. 1st fl.)  Dr. Yukiaki Ishida / ISSP, University of Tokyo  Time-resolved ARPES study of Dirac and topological materials
137 Sep. 13 (Wed.), 4 PM  #1323 (E6-2. 1st fl.)  Prof. Yi. Zhou (The Zhejiang Univ.)  An Introduction to Quantum Spin Liquids file
136 Sep. 12 (Tue.), 4 PM  #1323 (E6-2. 1st fl.)  Prof. Yi. Zhou (The Zhejiang Univ.)  Exact Solution for the Interacting Kitaev Chain at Symmetric Point file
135 AUG. 31 (Thu.), 2 PM  #5318(E6-2. 5th fl.)  Prof. Hiroaki Ishizuka (The University of Tokyo)  “Berry phase and nonlinear response: photocurrent in noncentrosymmetric insulators and Weyl semimetals” file
134 Aug. 16 (Wed.), 4 PM  #1322 (E6-2. 1st fl.)  Prof. Noejung Park (UNIST)  Phonon-driven spin-Floquet valleytro-magnetism file
133 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
132 #1323(E6-2. 1st fl.)  Jul. 10th (Mon), 4pm  Dr. Duk Young Kim Los Alamos National Laboratory  “Intertwined Orders in a Heavy-fermion metal” file
131 Jun. 2 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. Euyheon Hwang(황의헌)  Quasiparticle Interference and Fourier transform scanning tunneling spectroscopy in WTe2 (Weyl semimetal) file
130 Jun. 2 (Fri.), 4:00 PM  #1323 (E6-2. 1st fl.)  Dr. Sang Wook Kim  Maxwell's demon in quantum wonderland file
129 May. 12 (Fri.), 01:30 PM  E6-2. 1st fl. #1323  Dr. Young Kuk Kim  Topological Dirac insulator
128 Apr. 27, 2017 (Thu) 4:00 pm  Seminar Room(#1323, E6-2)  Prof.Donghan Lee (Chungnam National Univ.)  반도체 양자점을 이용한 단광자 광원
127 Apr. 28 (Fri.), 04:00 PM  #1323 (E6-2. 1st fl.)  Dr. Minkyung Jung Research Institute, DGIST  Carbon nanotubes coupled to superconducting impedance matching circuits
» 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
125 April 6, 2017 (Thu), 4:00 pm  IBS CAPP seminar room, Creation Hall (3F), KAIST Munji Campus  Prof. Youngjoon Kwon (Yonsei University)  For whom the Belle tolls
124 April 5th 2017, 12:00 ~ 13:00  Room 101, Creative Learning Bldg.(E11)  Prof. Wonho Choe(Dept. of Physics),Prof. Young-chul GHIM(Dept. of Nuclear & Quantum Engineering)  2017년 4월 첫수 융합포럼 개최 안내(물리학과 & 원자력 및 양자공학과 공동 개최)/The First Wednesday Multidisciplinary Forum in April 2017 organized by Dept. of Physics & Dept. of Nuclear & Quantum Engineering file