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 Sep.22 2022  E6-1 #1323    2022 가을학기 응집물리 및 광학 세미나 전체 일정
341 November 21 (Wed.), 15:00 PM  #1323, E6-2  Prof. Seongshik Oh  Engineering topological quantum physics at the atomic scale file
340 November 20 (Wed.), 4:00 PM  #5302, E6-2  Dr. Shigeyuki Ishida  Correlation between superconducting transition temperature and critical current density in irradiated iron-based superconductors file
339 November 14 (Thu.), 16:00 PM  #1323, E6-2  Prof. Ji-Hun Kang  Semi-classical model of polariton propagation file
338 November 1 (Thu.), 16:00 PM  #1323, E6-2  Dr. KyeoReh Lee  Direct holography from a single snapshot file
337 Nov.26(Thu), 04:00PM  Online(Zoom)  Myung-Ki Kim  2020 가을학기 광학분야 특별세미나(Light Engineering Beyond the Diffraction Limit)
336 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
335 Nov. 9 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. Pilkyung Moon  Moiré superlattices – from twisted bilayer graphene to quasicrystal file
334 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
333 Nov. 3 (Thu), 4:00PM  E6-2 #1323  문효원(한국과학기술원연구원 박사)  (광학분야 세미나) Single-photon emission from low-dimensional materials
332 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
331 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
330 Nov. 29(Tue) 4p.m.  #1323(E6-2. 1st fl.)  Dr. SungBin Lee, KAIST  Symmetry Protected Kondo Metals and Their Phase Transitions
329 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
328 Nov. 25 (Fri), 11:00AM  E6-2 #1323  이승섭(서울대 물리천문학부 교수)  (응집물리 세미나) DMFT+ NRG: From models to real materials, from local to nonlocal correlations
327 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
326 Nov. 24 (Thu) 2022, 4:00PM  E6-2 #1323  유정완(기초과학연구원, Center for Theoretical Physics of Complex Systems 교수)  (광학분야 세미나) Non-Hermitian physics and non-Hermitian singularity
325 NOV. 23 (Fri), 03:00 PM  E6-2. 2st fl. #2501  Prof. Sang-Jin Sin  Entanglement string and Spin Liquid with Holographic duality file
324 Nov. 22th (Thur), 15:00  E6 Room(#1323)  Prof. Suprijadi Haryono  Experimental and Computational Study on Physical Properties based on Granular System file
323 Nov. 20 (Fri.), 04:00 PM  Online  Dr. Dohun Kim  Coherent control of field gradient induced quantum dot spin qubits
322 Nov. 20 (Fri.), 02:30 PM  Online  Dr. Doohee Cho  Lumpy Cooper pairs in an iron-based superconductor