• 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




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
332 March 18(Fri.) 11:00  Online seminar  Dr. Dirk Wulferding (IBS-Center for Correlated Electron Systems, Seoul National University, Seoul)  (응집물리 세미나) Illuminating exotic states of matter: Raman spectroscopy as an experimental tool to characterize quantum spin liquids file
331 April 15(Fri.) 11:00  Online seminar  Prof.Jaekwang Lee (Department of Physics, Pusan National University)  (응집물리 세미나) First-principles studies of polar oxides and their applications file
330 June 3rd, Fri. 9:30 AM  Online seminar  Prof. Juejun Hu ( Massachusetts Institute of Technology)  (Quantum-&Nano-Photonics Webinar) Seeing glass in a new light: reimagine chalcogenide photonics file
329 Jun. 10 (Fri.), 11:00 AM  Online seminar  Dr. Yoon Jang Chung(Laboratory for Physical Sciences, University of Maryland)  Record-quality two-dimensional electron systems file
328 May. 14 (Fri.), 02:30 PM  Online seminar  Dr. Suyong Jung(KRISS)  Electrically tunable spin valve effect in vertical van-der-Waals magnetic tunnel junctions file
327 Jan.28(Thu), 06:00PM  Online Seminar  Alexandre Zagoskin(Loughborough Univ.)  Quantum metamaterials: concept, theory, prototypes and possible applications file
326 7월 29일(목) 오후 2시 ~ 오후 4시  Online seminar  Dr. Kunio Kaneta(KIAS)  Gravitationally Induced Dark Sector and Inflationary Dynamics file
325 Jun. 11 (Fri.), 02:30 PM  Online seminar  Dr. Jin Woong Cha(KRISS)  Engineering sound waves and vibrations in multi-mode nanomechanical systems file
324 Jun. 11 (Fri.), 04:00 PM  Online seminar  Dr. Keun Su Kim(Yonsei University)  Pseudogap in surface-doped black phosphorus file
323 May. 14 (Fri.), 04:00 PM  Online seminar  Dr. Je-Hyung Kim(UNIST)  Spatial and temporal separation of environmental dephasing sources from solid-state quantum emitters file
322 4pm, 31th March  online  최현용 (서울대학교 물리천문학부)  (광학분야 특별세미나)Ultrafast time-resolved spectroscopy in topological materials
321 3pm, 19th May  online  Jonghee Yoon, PhD (Assistant professor, Department of Physics, Ajou University)  (광학분야 특별세미나)Development of a multimodal optical system for improved disease diagnosis
320 3pm, 19th May  online  Jonghee Yoon, PhD (Assistant professor, Department of Physics, Ajou University)  (광학분야 특별세미나)Development of a multimodal optical system for improved disease diagnosis
319 Nov. 20 (Fri.), 02:30 PM  Online  Dr. Doohee Cho  Lumpy Cooper pairs in an iron-based superconductor
318 Mar 2 (Tue.), 16:00  Online  Dr. Dmitry Svintsov  Sensitive terahertz detection with graphene-based transistors file
317 Dec. 11 (Fri.), 04:00 PM  online  Hyobin Yoo(Sogang Univ.)  Atomic and electronic reconstruction at van der Waals interface in twisted 2D materials
316 Dec. 11 (Fri.), 02:30 PM  online  Myung Hwa Jung(Sogang Univ.)  Antisymmetric interlayer exchange coupling in magnetic multilayers
315 Dec.23(Wed), 10:00~16:00  Online  Prof. YongKeun Park (KAIST) and etc.  Online workshop for Quantitative Phase Imaging file
314 Nov. 20 (Fri.), 04:00 PM  Online  Dr. Dohun Kim  Coherent control of field gradient induced quantum dot spin qubits
313 Feb.17(Wed)~19(Fri), 09:00~11:00AM  Online  Prof. Subir Sachdev (Harvard University)  석학 대중 강연 및 강의 시리즈 file