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
575 2018-09-07 15:00  학술문화관 (E9), 2층 양승택 오디토리움  Recent developments in density functional theory: From new functionals to the nature of the chemical bond file
574 2016-05-17 11:00  창의학습관(E11), 406호  The CERN Resonant WISP Search: Development, Results and Lesson-Learned
573 2022-05-13 16:00  자연과학동(E6-2) 1st fl. #1323  High-fidelity iToffoli gate for fixed-frequency superconducting qubits file
572 2024-09-03 12:00  자연과학동(E6-2) 1323  2024 가을학기 물리학과 특별세미나 전체 일정 (응집물리 및 광학분야) file
571 2021-11-02 16:00  자연과학동(E6-2) #1323  Metrology of Band Topology via Resonant Inelastic X-ray Scattering file
570 2017-12-13 13:30  자연과학동 대형강의실 (1501호)  KAIST-KIAS Joint Workshop in Theoretical Sciences 개최 file
569 2024-09-02 16:00  자연과학동 1501호(공동강의실)  2024학년도 가을학기 물리학과 콜로키움(Physics Colloquium) file
568 2024-10-17 16:00  온라인 (https://kaist.zoom.us/j/89289652931?pwd=eNz6xnTFrEMGXYj9fXpdBJsW9fEpJX.1)  Photonic Methods for Quantum Levitodynamics Beyond the Rayleigh Regime
567 2021-05-27 16:00  온라인  찾아가는 물리연구 현장(유럽 입자물리학연구소 소개) file
566 2018-08-01 11:00  양분순 빌딩 (E16-1) 207호  Future of AI: Is the brain a computer? file
565 2022-04-01 16:00  Zoom webinar  High-field Electron Transport and Interaction Induced Phenomena in 2D Materials file
564 2020-09-14 17:30  Zoom webinar  KAIST Global Forum for Spin and Beyond (Third Forum) file
563 2020-09-22 09:30  Zoom webinar  Physics and applications of soliton microcombs(Quantum- & Nano-Photonics) file
562 2021-04-19 19:00  Zoom webinar  Evidence of Electrical Switching in Antiferromagnets and Coherent Spin Pumping file
561 2021-06-08 10:00  Zoom webinar  Photonic crystal devices for sensing file
560 2022-05-13 14:30  Zoom webinar  Topological Superconducting Spintronics Towards Zero-Power Computing Technologies file
559 2020-08-17 20:00  Zoom webinar  Using magnetic tunnel junctions to compute like the brain file
558 2020-09-28 17:30  Zoom webinar  KAIST Global Forum for Spin and Beyond(Fourth Forum) file
557 2020-08-25 20:00  Zoom webinar  KAIST Global Forum for Spin and Beyond (Second Forum) file
556 2021-12-03 16:00  Zoom webinar  Nonequilibrium Heat Transport in Elemental Metals Probed by an Ultrathin Magnetic Thermometer file