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
292 Sep. 4 (Tue), 02:30 PM  E6-2. 2st fl. #2502  Dr. Changmin Lee, MIT  Ultrafast time- and angle-resolved photoemission spectroscopy (tr-ARPES) with extreme ultraviolet laser pulses file
291 May. 3 (Fri), 11:00 AM  E6-2. 2st fl. #2502  Prof. Changhee Sohn  Exotic Magnetism file
290 NOV. 23 (Fri), 03:00 PM  E6-2. 2st fl. #2501  Prof. Sang-Jin Sin  Entanglement string and Spin Liquid with Holographic duality file
289 MAR. 26 (TUE), 0300 PM  E6-2. 2st fl. #2501  Prof. Jung Hoon Han  Consideration of thermal Hall effect in frustrated and un-frustrated quantum magnets file
288 JAN. 7 (Mon), 03:00 PM  E6-2. 2st fl. #2501  Dr. Byoung min Kang  Many-Body Invariants for Multipoles in Higher-Order Topological Insulators file
287 Jun. 18 (MON), 10:00 AM  E6-2. 2nd fl. #2502  Dr. Thibault VOGT  Rydberg electromagnetically induced transparency and microwave-to-optical conversion using Rydberg atoms file
286 2015/10/16, 4PM  E6-2. 2nd fl. #2501  Prof. Yung-Fu Chen(Solid-state Laser Physics Laboratory,National Central University)  Fluctuations of entropy production in partially masked electric circuits
285 Jan.9 (Wed.), 04:00 PM  E6-2. 2nd fl. #2501  Dr. Heung-Sik Kim  Molecular Mott state in the deficient spinel GaV4S8 file
284 2015/09/14, 2PM  E6-2. 2nd fl. #2501  Dr. Hae Ja Lee ( Stanford University, SLAC )  Ultrafast X-ray Studies on Dynamics Matter in Extreme Conditions
283 Apr. 01 (Fri.) 2:30 PM  E6-2. 1st fl. #1501  Dr. KICHEON KANG, Chonnam National University  Interference of single charged particles without a loop and dynamic nonlocality
282 Apr. 01 (Fri.) 4:15 PM  E6-2. 1st fl. #1501  Dr. JONG SOO LIM, KIAS  Cotunneling drag effect in Coulomb-coupled quantum dots
281 2016/03/11 4 PM  E6-2. 1st fl. #1501  Dr. Tae-Hwan KIM (POSTECH)  Jan. Switching handedness of of chiral solitons in Z4 topological insulators
280 Apr. 08 (Fri.), 13:30 PM  E6-2. 1st fl. #1501  Dr. Yunkyu Bang, Chonnam National Univ.  Theoretical Overview of Iron-based superconductors and its future
279 2016/03/11 1:30 PM  E6-2. 1st fl. #1501  Dr. Kwon Park  Topological phases of matter in nonequilibrium: Topology of the Wannier-Stark ladder
278 May. 25(Wed), 4pm  E6-2. 1st fl. #1323 / Zoom  Dr. Sungwoo Hong (Enrico Fermi Institute at University of Chicago)  Uncovering New Lampposts for Dark Matter: Continuum or Conformal
277 Jun. 10 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. Seunghun Lee(Department of Physics, Pukyong National University)  Combinatorial strategy for condensed matter physics: study on rare earth hexaborides thin films file
276 Jun. 10 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. Sanghoon Kim(Department of Physics, University of Ulsan)  Fe5GeTe2의 나선형 자성특성과 자기저항의 전류밀도 의존성 연구 file
275 May. 11 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. Nam Kim  암페어 단위 재정의와 단전자 펌프 소자 개발 file
274 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
273 Dec. 7 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. Gyung Min Choi  Spin generation from heat and light in metals file