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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
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공지 2019/09/02 - 12/09  Seminar Room 1501  이호성 박사 (한국표준과학연구원) and etc.  Fall 2019: Physics Colloquium
100 May 16, 2016 (Mon) 4PM  #1323(E6-2, 1st Fl.)  Dr. Daniel Bowring , Fermi National Accelerator Laboratory  Tuning microwave cavities with biased nonlinear dielectrics for axion searches
99 May 19 (Thu) 4PM  #1323(E6-2, 1st fl.)  Dr. Heedeuk Shin, POSTECH  Nonlinear/quantum optical effect in silicon nano-photonics
98 May 19, 2016 (Thur.) 3PM  May 19, 2016 (Thur.) 3PM,  Dr. Michael Betz, CERN  The CERN Resonant WISP Search: Development, Results and Lesson-Learned
97 May 2 (Thu.), 4:00 PM  #1323, E6-2  Prof. Joon Ik Jang  Anomalous optical properties of halide perovskites file
96 May 21 (Tue.), 4:00 PM  #5318, E6-2  임준원 박사  Classification of flat bands according to the band-crossing singularity of Bloch wave functions file
95 May 24 (Fri.), 16:00 PM  #1323, E6-2  Prof. Soonjae Moon  Infrared spectroscopy study on metal-insulator transitions in layered perovskite iridates file
94 May 24 (Tue) 4 PM  E6-2. #1323(1st fl.)  Dr. Euyheon Hwang, SKKU Advanced Institute of Nanotechnology, Sung Kyung Kwan University  Electronic and magnetic properties of 2D transition-metal thiophosphates and tunability of magnetic order with carrier density
93 May 29 (Tue.), 04:00 PM  #1323, E6-2  Prof. Jae-Won Jang  Investigation on metal nanostructure/semiconductor junction and its applications file
92 May 30 (Thu.), 16:00 PM  #1323, E6-2  Prof. Chang-Hee Cho  Tuning the excitonic properties of semiconductors with light-matter interactions file
91 May 31 (Fri.), 11:00 AM  #1323, E6-2  Prof. Guido Burkard  Cavity QED with Spin Qubits file
90 May 31 (Tue.) 4 PM  #1323(E6-2, 1st fl.)  Dr. Kimin Kim, KAIST  Understanding 3D tokamak physics towards advanced control of toroidal plasma
89 May 311 (Thu.), 04:00 PM  #1323, E6-2  Prof. Teun-Teun Kim  Dynamic control of optical properties with gated-graphene metamaterials file
88 May. 8th (Wed), 16:00  E6 Room(#1323)  Jieun Lee  Imaging valley dependent electron transport in 2D semiconductors file
87 May 9 (Thu.), 16:00 PM  #1323, E6-2  Prof. Kwang Geol Lee  Quantum Optical Sensing Using Single Photons And Single Photon Emission from Single Emitters file
86 May 9 (Thu.), 16:00 PM  #1323, E6-2  Prof. Kwang Geol Lee  Quantum Optical Sensing Using Single Photons And Single Photon Emission from Single Emitters file
85 May 9 (Wed.), 04:00 PM  #1323, E6-2  Prof. Jong-Soo Rhyee  Recent advances in thermoelectric bulk composites file
84 May. 11 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. Kun Woo Kim  Disordered Floquet topological insulators file
83 May. 11 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. Nam Kim  암페어 단위 재정의와 단전자 펌프 소자 개발 file
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81 May. 17 (Thu.), 01:30 PM  E6-2. 1st fl. #1323  Prof. Yong-Baek Kim University of Toronto  Quantum Spin Liquid in Kitaev Materials file