G
Geunsik Lee
Researcher at Ulsan National Institute of Science and Technology
Publications - 146
Citations - 6556
Geunsik Lee is an academic researcher from Ulsan National Institute of Science and Technology. The author has contributed to research in topics: Graphene & Catalysis. The author has an hindex of 31, co-authored 125 publications receiving 5118 citations. Previous affiliations of Geunsik Lee include Pohang University of Science and Technology & University of Texas at Dallas.
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Journal ArticleDOI
The Role of Oxygen during Thermal Reduction of Graphene Oxide Studied by Infrared Absorption Spectroscopy
Muge Acik,Geunsik Lee,Cecilia Mattevi,Adam Pirkle,Robert M. Wallace,Manish Chhowalla,Kyeongjae Cho,Yves J. Chabal +7 more
TL;DR: In this article, the role of trapped water and the evolution of oxygen during annealing of reduced graphene oxide (GO) is investigated, and the interactions between randomly arranged nearby oxygen species are found to affect the spectral response (red and blue shifts) and the overall chemistry during the reduction process.
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Unusual infrared-absorption mechanism in thermally reduced graphene oxide
Muge Acik,Geunsik Lee,Cecilia Mattevi,Cecilia Mattevi,Manish Chhowalla,Manish Chhowalla,Kyeongjae Cho,Yves J. Chabal +7 more
TL;DR: The observation of a giant-infrared-absorption band in reduced graphene oxide is reported, arising from the coupling of electronic states to the asymmetric stretch mode of a yet-unreported structure, consisting of oxygen atoms aggregated at the edges of defects.
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Multicomponent electrocatalyst with ultralow Pt loading and high hydrogen evolution activity
Jitendra N. Tiwari,Siraj Sultan,Chang Woo Myung,Taeseung Yoon,Nannan Li,Miran Ha,Ahmad M. Harzandi,Hyo Ju Park,Dong Yeon Kim,Srinivasan Chandrasekaran,Wang-Geun Lee,Varun Vij,Hoju Kang,Tae Joo Shin,Hyeon Suk Shin,Geunsik Lee,Zonghoon Lee,Kwang S. Kim +17 more
TL;DR: In this article, a multicomponent catalyst with an ultralow Pt loading (1.4μg per electrode area (cm2)) supported on melamine-derived graphitic tubes (GTs) that encapsulate a FeCo alloy and have Cu deposited on the inside tube walls.
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First-principles study of metal–graphene interfaces
TL;DR: In this paper, first-principles calculations were applied to twelve metal-graphene interfaces and investigated the detailed interface atomic and electronic structures of physisorption and chemisorsorption interfaces, showing that external electric field can be used to modulate graphene energy-levels and the corresponding control of doping or energy range of hybridization.
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The role of intercalated water in multilayered graphene oxide.
Muge Acik,Cecilia Mattevi,Cheng Gong,Geunsik Lee,Kyeongjae Cho,Manishkumar Chhowalla,Yves J. Chabal +6 more
TL;DR: IR spectroscopy, XPS analysis, and DFT calculations all confirm that the water molecules play a significant role interacting with basal plane etch holes through passivation, via evolution of CO(2) leading to the formation of ketone and ester carbonyl groups.