Browsing by Author "Pan, Chien-Chung"

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Carbon Nanotube/Nitrogen-Doped Reduced Graphene Oxide Nanocomposites and Their Application in Supercapacitors
(2017-08-01)
Yang, Chih-Chieh
;
Tsai, Meng-Han
;
Huang, Chun-Wei
;
Yen, Po-Jen
;
Pan, Chien-Chung
Electrodes of carbon-based nanocomposites with high specific surface areas and suitable pore sizes have high potential for improving power and energy densities of supercapacitors. In this study, nitrogen-doped reduced graphene oxide (NrGO) nanosheets were synthesized to increase the specific surface area of reduced graphene oxide (rGO). The specific surface area of NrGO was increased to 633 m(2)g(-1) compared to that of rGO, 450 m(2)g(-1). A series of NrGO/carbon nanotubes (CNTs) nanocomposites were prepared. By using NrGO/CNTs/polyvinylidene difluoride (PVDF)/carbon black/N-methyl-pyrrolidone (NMP) nanocomposites as both of anode and cathode into two electrodes, such symmetric supercapacitor in the 1 M KOH aqueous electrolyte exhibited high specific capacitance (227 F g(-1) at 20 mV s(-1)), fast rate capability (83% capacitance of current density 1 mA cm(-2) at current density 5 mA cm(-2)), low resistance (0.98 Omega), and excellent cycling stability (87% capacitance retention after 10,000 charge/discharge cycles). Moreover, the symmetric supercapacitor in the ionic liquid (BMIMTFSI) electrolyte possessed a wide operating voltage (3 V) and high energy density (89 Wh kg(-1) at 1 mA cm(-2)). The carbon-based hybrid electrode has high potential for use in energy storage and conversion devices.
Production of few-layer MoS2 nanosheets through exfoliation of liquid N-2-quenched bulk MoS2 dagger
(2014)
Van Thanh, Dang
;
Pan, Chien-Chung
;
Chu, Chih-Wei
;
Wei, Kung-Hwa
;
材料科學與工程學系
We demonstrate an efficient method for the production of few-layer MoS2 nanosheets through exfoliation of bulk MoS2 compounds that were subject to quenching in liquid N-2 and subsequent ultrasonication. This solution- based method, which involves a "quenching cracks" phenomenon, was performed open to the atmosphere. Subsequent ultrasonication of the exfoliated MoS2 in solution provided us with MoS2 nanosheets comprising two to four layers.