visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2017-04-28 14:30 
연사  
장소 E6-2. 1st fl. #1323 

 

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 연사 제목
공지 2025-02-24 16:00    2025년 봄학기 콜로키움 안내
공지 2025-02-27 16:00    2025년 봄 물리학과 특별세미나 (광학/응집물리 분야)
445 2018-11-22 15:00    Experimental and Computational Study on Physical Properties based on Granular System file
444 2021-02-17 09:00    석학 대중 강연 및 강의 시리즈 file
443 2019-04-04 16:00    Chiral spin-photon interaction at nanoscale file
442 2023-11-22 10:00    [High Energy Theory Seminar] Exact Quantum Algorithms to Recognize Quantum Phases of Matter
441 2019-05-24 16:00    Infrared spectroscopy study on metal-insulator transitions in layered perovskite iridates file
440 2023-06-16 13:00    Quantum critical states under extreme conditions
439 2019-12-05 16:00    Subwavelenth Photonic Devices: From Single Photon Sources to Solar Cell file
438 2018-10-04 16:00    Engineering light absorption in an ultrathin semiconductor metafilm file
437 2019-07-10 16:00    Public Lectures file
436 2019-07-16 16:00    2019 Physics Distinguished Lecture file
435 2019-12-18 16:00    Road to Higher Tc Superconductivity file
434 2016-06-14 15:00    No-Insulation High Temperature Superconductor Magnet Technology for Compact, Reliable, and Low-Cost High Field DC Magnets
433 2018-11-21 15:00    Engineering topological quantum physics at the atomic scale file
432 2022-04-08 11:00    (응집물리 세미나) Flat-surface-assisted physical phenomena occurring in single crystal metal thin film file
431 2019-10-29 10:00    Unconventional Spin Transport in Quantum Materials file
430 2021-02-02 14:30    Quantum- & Nano-Photonics 세미나(Integrated Nanophotonics with Metamaterials, Microcomb, and Atomic Systems) file
429 2018-11-23 15:00    Entanglement string and Spin Liquid with Holographic duality file
428 2018-06-22 10:00    Success in Research Career file
427 2016-04-18 15:30    First Principles Approaches for Intermolecular Interactions: From Gas-Phase Dimers to Liquid Water and Molecular Crystal Polymorphism file
426 2020-12-02 10:00    Recent progress in Axion Dark Matter eXperiment (ADMX) technology file