Oxidation of Single-Walled Carbon Nanotubes under Controlled Chemical Conditions

Abstract

Single-walled carbon nanotubes are oxidized in the presence of H 2 SO 4 /HNO 3 mixtures containing distinct concentrations of the nitronium ion, [NO 2 + ]. The spectroscopic analyses of the final samples suggest a higher structural disorder in the oxidized systems with increasing [NO 2 + ]. This is due to a considerable oxygen amount on the tube surface, reaching up to 30%, depending on the reaction time and [NO 2 + ]. Interestingly, if long reaction time is considered, the oxygen amount on the tube surface is maximum for low [NO 2 + ] and reduces slightly for larger [NO 2 + ]. On the other hand, the oxidation process occurs gradually at 4 h, allowing a fine control of the oxidation process. Therefore, if fine tuning of the oxidation degree is desirable, the reaction must be conducted during short time (4 h) using increasing [NO 2 + ] as those obtained from 2:1, 2.5:1 and 3:1 H 2 SO 4 /HNO 3 acid mixtures to produce increasing content of functionalization.

Membranes of Multiwall Carbon Nanotubes in Chitosan–Starch with Mechanical and Compositional Properties Useful in Li-Ion Batteries

“…A significant decrement in the D/G ratio in comparison with the MWNTs is observed in the lithium-modified samples, in accordance with various publications [92][93][94][95][96][97][98][99], indicating a possible exfoliation of carbon nanotubes. It is also important to mention that the small peaks that appear in the spectra refer to normal vibration modes that are affected in position due to the oxidation of multiwall carbon nanotubes [100]. Furthermore, the G'/G and G'/D are larger in RLi than in SLi, indicating that there is an increment in the G' band with respect to the The samples intercalated with lithium show a drop in G'/D compared to MWOHs due to the decrement in the area of G' caused by the exfoliating action of LiOH, which degrades carbonaceous materials [89,90].…”

A Concise Guide to Silicone-Based Spring-Roll Actuator Assembly

“…Prior to dispersing, CNTs were functionalised according to an established procedure [30]. CNTs were oxidised using a 1:2 mixture of H 2 SO 4 :HNO 3 , where the weight ratio of CNTs to the mixture was chosen as 1:50.…”

Strongly coupled C@MoSe2@OMWCNT heterostructure as an anode for Na+ batteries

“…Strongly coupled hybrids (SC-hybrids) of inorganic nanomaterials and oxidized carbon (C) materials, such as oxidized carbon nanotubes (OCNTs), are produced by the bonding of the functional groups of the OCNTs [1][2][3][4][5][6]. The bonding between inorganic materials and oxidized carbon affords enhanced electron transport and an increased rate ability of the hybrids as anodes for SIBs [2][3][4][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. MoSe 2 has become an anode material for SIBs due to its high theoretical capacity [22][23][24][25].…”

“…In addition, after acid treatment, oxidized functional groups (-OH, -COOH, C = O, etc.) were introduced [19,[34][35][36]. Inorganic nanomaterials (MoSe 2 ) can be rmly anchored by functional groups on oxidized carbon nanotubes (OCNTs) [6,31,32].…”