123rd General Meeting of the KCS

Type Poster Presentation
Area Inorganic Chemistry
Room No. Exhibition Hall 2
Time 4월 18일 (목요일) 11:00~12:30
Code INOR.P-16
Subject Electrochemical capacitances and gas sorption properties of N-doped microporous carbon nanospheres and their KOH-activated derivatives
Authors Hyun-Chul Kim, Minsun Park, Seong Huh*
Department of Chemistry, Hankuk University of Foreign Studies, Korea
Abstract Sub-200 nm N-doped microporous carbon nanospheres (MCNs) were directly prepared from the carbonization of as-prepared mesoporous silica nanospheres (MSNs) containing cetylpyridinium bromide (CTPB) template. After silica-etching by using HF, N-doped MCNs were obtained. The gas sorption properties and electrochemical capacitive behaviors of the N-doped MCNs were evaluated by standard volumetric method and 3-electrode measurement. The KOH-activated derivatives were also prepared for the enhancement of electrochemical supercapacitive properties. Different amounts of KOH were employed to prepare a series of KOH-activated MCNs: MCN-nKOH (n denotes the weight ratio of KOH to MCN used for activation). The N-doped MCN-nKOH series revealed superior gas uptake abilities than N-doped MCN. The N-doped MCN-2KOH sorbed 478.2 cm3 g-1 (21.33 mmol g-1) of CO2 at 196 K, 2.22 wt % (11.03 mmol g-1) of H2 at 77 K and 162.9 cm3 g-1 (7.27 mmol g-1) of CH4 at 196 K. Furthermore, the KOH-activated MCNs displayed enhanced rate capabilities of capacitance compared to the N-doped MCN. The N-doped MCN-2KOH showed the highest specific capacitance of 459.6 F g-1 and maximum specific energy of 37.6 Wh kg-1 at 0.1 A g-1. It also exhibited high specific power of 53,323 W kg-1 at 120 A g-1. The N-doped MCN-nKOH materials showed very excellent electrochemical cycling stabilities up to 30,000 cycles.
E-mail khc@hufs.ac.kr