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
469 2023-06-01 16:00  E6-2 #1323  (광학분야 세미나)Quantum sensing using a squeezed light from hot Rb vapor
468 2023-05-31 16:00  E6-2, #2502  [High-Energy Theory Seminar] Resurgence and complex Chern-Simons theory
467 2023-05-26 11:00  E6-2 #1323  (응집물리 세미나)Spectral Analyses of Stochastic Charge Trapping in Oxide Heterostructures file
466 2023-05-22 13:00  E6-6 119  Design & Development of Electrochemical Biosensors for the Detection of T2DM Biomarkers
465 2023-05-19 11:00  E6-2 #1323  (응집물리 세미나)Dipole condensations in Tilted Bose-Hubbard Chains
464 2023-05-18 16:00  E6-2 #1323  (광학분야 세미나)Dielectric metasurfaces for optimized optical system and spatial light modulators
463 2023-05-17 16:30  Zoom  Detecting Hidden Photon Dark Matter via the Excitation of Qubits file
462 2023-05-17 14:00  E6 #1323  Optical Response in the multilayer thin films
461 2023-05-15 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  Role of dark Higgs boson in DM physics and cosmology file
460 2023-05-12 11:00  E6-2 #1323  (응집물리 세미나)Interlayer conductivity and plasmon in weakly coupled layered systems
459 2023-05-03 16:00  E6-2, #2502  Probing microscopic origins of axions by the chiral magnetic effect
458 2023-04-28 11:00  E6 #1323  Tkachenko wave: From the modern field theory viewpoint
457 2023-04-27 16:00  E6-2 #1323  (광학분야 세미나)On-chip spectrometers based on CMOS image sensors
456 2023-04-27 11:00  E6-2 #1322  Inverse Shapiro steps and coherent quantum phase slip in superconducting nanowires
455 2023-04-14 12:00  E6-2 #1323  (응집물리 세미나)Exotic quantum phenomena in two-dimensional materials file
454 2023-04-13 11:00  Zoom  [High Energy Theory Seminar]Noninvertible Gauss Law and Axions
453 2023-04-06 16:00  E6-2 #1323  (광학분야 세미나)Nanophotonics-based approaches to explore Berry physics
452 2023-04-05 16:00  E6-2, #2502  [High Energy Theory Seminar]Anomalies of Discrete 1-Form Symmetries in QCD-like Theories
451 2023-04-04 16:00  Room 2501, KAIST Natural Sciences Lecture Hall(E6)  Chiral Magnetism: A Geometric Perspective
450 2023-03-30 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  Detecting axions with chiral magnetic effects file