Synthesis of Carbon/Carbon Core/Shell Nanotubes with a High Specific Surface Area

Abstract

Novel carbon/carbon core/shell nanotubes (C/C-NTs) composed of well-crystallized core carbon nanotubes (CNTs) and structurally disordered carbon shells were prepared for obtaining a new type of nanotube material with high specific surface area (SSA). The disordered carbon shells were prepared by coating polyaniline (PANI) layers on the core CNTs through in situ polymerization and subsequent carbonization. Chemical activation was conducted for the C/C-NTs with KOH at 1123 K to prepare activated C/C-NTs (AC/C-NTs). Scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction, Raman spectroscopy, and an adsorption analyzer were used to characterize the nanotube samples. The outer carbon shells thermally converted from the PANI layers are much less ordered and thus much more reactive than the CNTs. The AC/C-NTs tend to have much higher SSA than that obtained by directly activating the CNTs, and the obtained SSA for the AC/C-NTs is as high as 2924 m 2 /g, which is the highest among the existing nanotube materials. TEM shows that the hollow structure and high crystallinity of the core CNTs were well preserved during carbonization and activation. The novel AC/C-NTs may find important applications in many areas such as supercapacitors, catalyst supports, adsorption, and hydrogen storage due to their superhigh SSA and nanotubular structure. The present work provides a way for preparing other core/shell nanotube or nanowire materials with high SSA.

Cotton-derived carbon fibers with high specific capacitance by ZnCl2 activation for supercapacitor application

“…In contrast, the CCFs0 without adding ZnCl 2 during carbonization show much lower adsorption capacity with a specific surface area of 89.6 m 2 g -1 . It is noted that the CCFs activated by ZnCl 2 possess higher mesopore percentage than the activated carbon prepared by the KOH [13], which is beneficial for supercapacitor applications [8,14]. The pore size distribution of CCFs2 and CCF3 in Fig.…”

Pyrolyzed polyaniline and graphene nano sheet composite with improved rate and cycle performance for lithium storage

“…The fitting values from this equivalent circuit are presented in Table 1. As it can be seen, the R SEI and R ct of the PAGNS0.5 and PAGNS1 electrode are 30.76 and 21.00, 16.59 and 20.87 X, respectively, much lower than those of the GNS electrode (R SEI and R ct of the GNS electrode are 31.12 and 56.22 X, respectively). Similarly, with the increase of content of pyrolyzed PANI, the R SEI and R ct of PAGNS tend to decrease.…”

“…The composite materials take advantages of synergistic effects and multiple functionalities resulting from interactions between the two compositions [15]. The pyrolysis of polymers such as polypyrrole, polypyrrolidone and polyaniline, used as carbon precursors, has also been investigated extensively [16][17][18][19].…”

Morphology control and high electrochemical performance of flower-like N-enriched porous carbons for supercapacitor

“…For porous carbon materials containing nitrogen, nitrogen-containing carbon precursors are prepared using polypyrrolidone (PPy), polyacrylonitrile (PAN), polyaniline (PANI), and melamine [16,17]. A number of methods have been developed for the preparation of porous activated carbons.…”