visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2017-04-28 14:30 
일시 Apr. 28 (Fri.), 02:30 PM 
장소 E6-2. 1st fl. #1323 
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 날짜 장소 제목
143 2017-11-03 14:30  #1323 (1st fl., E6-2.)  Quantum Resistor-Capacitor Circuit with Majorana Edge States file
142 2017-10-10 16:00  E6-2 #1323  Discovery of New 2D Materials with Diverse Physical Properties
141 2017-09-26 11:00  #1323 (E6-2. 1st fl.)  Time-resolved ARPES study of Dirac and topological materials
140 2017-09-22 16:00  E6-2. 1st fl. #1323  Unexpected Electron-Pairing in Integer Quantum Hall Effect file
139 2017-09-22 14:30  E6-2. 1st fl. #1323  Quantum Electronic Transport in Graphene Hybrid Nanostructures file
138 2017-09-22 13:00  E6-2. 1st fl. #1323  Superconductor-metal-insulator transition in thin Tantalum films file
137 2017-09-13 16:00  #1323 (E6-2. 1st fl.)  An Introduction to Quantum Spin Liquids file
136 2017-09-12 16:00  #1323 (E6-2. 1st fl.)  Exact Solution for the Interacting Kitaev Chain at Symmetric Point file
135 2017-08-31 14:00  #5318(E6-2. 5th fl.)  “Berry phase and nonlinear response: photocurrent in noncentrosymmetric insulators and Weyl semimetals” file
134 2017-08-16 16:00  #1322 (E6-2. 1st fl.)  Phonon-driven spin-Floquet valleytro-magnetism file
133 2017-07-14 15:00  #1323 (E6-2. 1st fl.)  Chiral anomaly in disordered Weyl semimetals file
132 2017-07-10 16:00  Jul. 10th (Mon), 4pm  “Intertwined Orders in a Heavy-fermion metal” file
131 2017-06-02 16:00  #1323 (E6-2. 1st fl.)  Maxwell's demon in quantum wonderland file
130 2017-06-02 14:30  E6-2. 1st fl. #1323  Quasiparticle Interference and Fourier transform scanning tunneling spectroscopy in WTe2 (Weyl semimetal) file
129 2017-05-12 13:30  E6-2. 1st fl. #1323  Topological Dirac insulator
128 2017-04-28 16:00  #1323 (E6-2. 1st fl.)  Carbon nanotubes coupled to superconducting impedance matching circuits
» 2017-04-28 14:30  E6-2. 1st fl. #1323  Hot electron generation at surfaces and its impact to catalysis and renewable energy conversion
126 2017-04-27 16:00  Seminar Room(#1323, E6-2)  반도체 양자점을 이용한 단광자 광원
125 2017-04-06 16:00  IBS CAPP seminar room, Creation Hall (3F), KAIST Munji Campus  For whom the Belle tolls
124 2017-04-05 12:00  Room 101, Creative Learning Bldg.(E11)  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