http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Luan, Van Hoang,Bae, Daeryeong,Han, Jong Hun,Lee, Wonoh Elsevier 2018 Composites Part B, Engineering Vol.134 No.-
<P><B>Abstract</B></P> <P>To facilitate the immobilization of the silver nanoparticles with high crystallinity and stability, the mussel-inspired dopamine is functionalized on the surface of the graphene. Considering the unique adhesive property of a catechol group in the dopamine toward metallic ions, a large amount of silver nanoparticles can be coated on the surface of the dopamine-functionalized graphene. To use the high surface area of graphene, large-sized graphene sheets are prepared using the microwave heat treatment of graphite powder followed by chemical oxidation and exfoliation. In addition, the large-area graphene sheets are selectively collected by a pH-assisted fractionation technique and are confirmed by the green-light filtered optical microscopic images. The dopamine-mediated graphene hybrid with silver nanoparticles shows superior electrochemical activity with enhanced electrical conductivity by promoting the decoration of stable silver nanoparticles on the surface of graphene. The resulting hybrid exhibits 7.6 times and 1.6 times higher electrochemical capacitance than that of the bare and graphene/silver hybrid-modified glassy carbon electrodes, respectively.</P>
Luan, Van Hoang,Tien, Huynh Ngoc,Hur, Seung Hyun Elsevier 2015 JOURNAL OF COLLOID AND INTERFACE SCIENCE - Vol.437 No.-
<P><B>Abstract</B></P> <P>Hybrid 3-dimensional (3D) structures composed of zinc oxide (ZnO) nanorods and reduced graphene oxide hydrogel (rGOH) were fabricated by chemical reaction between Zn ions and GO followed by <I>in-situ</I> lateral growth of ZnO nanorods using Zn ions as seed points. The 3D networked ZnO nanorod–rGOH (ZNR–rGOH) fabricated in this study exhibited excellent methylene blue (MB) removal efficiency due to efficient physical adsorption of dye molecules because of electrostatic attractive forces and enhanced photocatalytic activity by the laterally grown ZnO nanorods. The Langmuir–Hinshelwood rate constant of ZNR–rGOH was 4-fold higher than that of pristine rGO due to the enhanced photocatalytic effects obtained by incorporating laterally grown ZnO nanorods inside the rGOH network.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The Covalently-bonded 3D networked graphene hydrogel was fabricated using Zn ions. </LI> <LI> ZnO nanorods were laterally grown inside rGOH networks using hydrothermal synthesis. </LI> <LI> Dye removal efficiency was highly enhanced by using hybrid structures. </LI> <LI> Visible light photocatalytic activity was also observed in the hybrid structures. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Luan, Van Hoang,Son, Hye Jeong,Chung, Jin Suk,Hur, Seung Hyun American Scientific Publishers 2017 Journal of Nanoscience and Nanotechnology Vol.17 No.10
<P>Herein, a three-dimensional (3D) reduced graphene oxide hydrogel (rGOH) was fabricated by crosslinking ethylene diamine (EDA) and the functional groups of GO in the presence of one-dimensional (1D) Ag nanowires (NWs). The Ag NWs increased the electrical conductivity and the pore size of the final 3D structures. The capacitance of Ag-rGOH (369 F g(-1)) was 1.7 times higher than that of EDA-rGOH (218 F g(-1)) and 1.3 times higher than that of a physically mixed sample with the same Ag content. Moreover, the Ag-rGOH electrode also exhibits excellent long-term stability with a capacitance retention of more than 90% over 1,000 cycles and a high energy of 2.2 Wh kg(-1) at 900 W kg(-1).</P>
Luan, Van Hoang,Han, Jong Hun,Kang, Hyun Wook,Lee, Wonoh Elsevier Science Ltd 2019 Composites Part B, Engineering Vol.178 No.-
<P><B>Abstract</B></P> <P>Three-dimensionally porous carbon nanostructures have been widely used in energy storage applications owing to their large specific surface areas and excellent electrical properties. In addition, copper oxide has been considered as an effective pseudocapacitive material to significantly increase the energy density. In this paper, we introduce the synergetic combination of one-dimensional copper oxide nanowires and two-dimensional graphene sheets to fabricate a highly porous and electrically conductive three-dimensional hybrid nanostructure for high-performance supercapacitor electrodes with increased capacitances. The copper oxide nanowires were synthesized by reduction of copper nitrate and sequential oxidation at a high temperature. The copper oxide nanowire/graphene hybrid three-dimensional nanostructure was obtained by a self-assembly technique through a simple hydrothermal treatment. The hybrid nanostructure had an acceptable surface area and increased thermal stability. The porous hybrid nanostructure utilized as a supercapacitor electrode provided 1.6 times higher electrochemical capacitance than that of a graphene-only nanostructure-based electrode as well as superior capacitance stability with a retention of 91.2% retention after 5,000 charge−discharge cycles. Owing to the increased capacitance, the manufactured electrode exhibited high a specific energy density of 50.6 Wh kg<SUP>−1</SUP> at a power density of 200 W kg<SUP>−1</SUP>, which demonstrates its potential for use in electrochemical energy storage devices.</P>
Yoo, Dae-Hwang,Cuong, Tran Viet,Luan, Van Hoang,Khoa, NguyenTri,Kim, Eui Jung,Hur, Seung Hyun,Hahn, Sung Hong American Chemical Society 2012 JOURNAL OF PHYSICAL CHEMISTRY C - Vol.116 No.12
<P>The photocatalytic performance of a multidimensional heterojunctioncomposed of decorated Ag nanoparticles on ZnO nanorods verticallygrown on a chemically converted graphene (CCG) was investigated. Thecombined heterojunction helps to improve photocatalytic activity byincreasing light absorption, preventing photoinduced electron–holerecombination, and providing a carrier pathway for the giant π-conjugatedsystem of CCG. A significant finding was that the low work functionvalue of Ag (−4.74 eV) at the (111) surface makes possiblethe transfer of electrons from CCG to Ag. Consequently, the degreeof photodegradation by Ag/ZnO/CCG is much higher than the sum of photodegradationsby Ag/ZnO and ZnO/CCG samples, which indicates that the combinationof metal, CCG, and semiconductor provides enhanced photocatalyticactivity through the double transference of electrons.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2012/jpccck.2012.116.issue-12/jp210216w/production/images/medium/jp-2011-10216w_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp210216w'>ACS Electronic Supporting Info</A></P>