Comparatively studying the ultrasound present in a mild two-stage approach on the content of functional groups in modified MWCNT

Tian, Run; Liang, Shaolei; Li, Guangfen; Zhang, Yanxia; Shi, Le

doi:10.1016/j.cplett.2016.02.050

Cited by 9 publications

(6 citation statements)

References 24 publications

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“…Furthermore, a π−π* transition loss peak is identified at 290.6 eV, which is similar to previous work. 49 The four components of the C 1s XPS spectrum of UCNTs are assigned to the carboxyl group O− C�O (288.2 eV), the hydroxyl group C−O (286.0 eV), sp 3 hybridized C−C (284.8 eV), and sp 2 -hybridized C�C (284.1 eV), respectively. 50,51 These four components can also be found in the C 1s spectrum of AcUCNTs.…”

Section: Resultsmentioning

confidence: 99%

Acetylation Strategy for Unzipping Carbon Nanotubes in High-Performance Lithium-Ion Batteries

Yang

Zhang

et al. 2022

ACS Appl. Nano Mater.

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Although carbon nanotubes (CNTs) have attracted tremendous attention as the lithium-ion battery (LIB) anode material considering their excellent electrochemical and mechanical properties, their low theoretical specific capacity severely limits the practical applications. The high specific capacities of organic carbonyl compounds in LIBs can be introduced to increase the specific capacity of CNTs. However, the inherent electrical insulating properties and low utilization of active sites of organic carbonyl compounds, as well as a high solubility in aprotic electrolytes, are severe concerns. Herein, we report a strategy of combining organic acetyl groups on unzipped CNTs (UCNTs) to address above issues, which not only tackles the poor conductivity and rapid dissolution of small organic molecules but also improves the specific capacity of CNTs. Acetylated UCNTs (AcUCNTs) display an admirable electrochemical performance in LIBs, with the first cycle discharge and charge capacities reaching 987.1 and 875.2 mA h g–1 at 200 mA g–1, respectively. More impressively, AcUCNTs retains a high capacity of 540.0 mA h g–1 after 87 cycles, which is dramatically higher than that of pristine CNTs. This research is important for providing a technology for combining organic and inorganic materials to achieve superior electrode materials, which is significant in the development of LIBs.

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Section: Resultsmentioning

confidence: 99%

Acetylation Strategy for Unzipping Carbon Nanotubes in High-Performance Lithium-Ion Batteries

Yang

Zhang

et al. 2022

ACS Appl. Nano Mater.

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“…So, although care must be taken to select the optimum conditions, dispersion of CNTs can be carried out with sonochemical assistance at much lower acid concentrations than are usually used and can hence offer a csafer, more environmentally friendly method. Cavitation also produces a large degree of turbulence and motion and the high shear forces generated break the CNTs, shortening the average length and leading to more open ends [11]. This is even more obvious when a higher ultrasound intensity was used (18 W cm -2 , Fig.…”

Section: Effect Of Ultrasound On Cnt Structurementioning

confidence: 99%

“…To reduce the severity of the reaction conditions necessary for CNT modification, sonochemical modification has recently been studied [11,12]. Among its many other applications, sonochemistry has also been widely applied in the synthesis of polymers and nanoparticles [13,14].…”

Section: Introductionmentioning

confidence: 99%

Sonochemical modification of carbon nanotubes for enhanced nanocomposite performance

Price

Nawaz

Yasin

et al. 2018

Ultrasonics Sonochemistry

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Multi-walled carbon nanotubes (CNTs) have been treated using 20kHz ultrasound in combination with dilute nitric and sulfuric acids at much lower concentrations than previously reported. The measurements revealed an optimum set of sonication conditions (in this case 30min at 12Wcm) exists to overcome aggregation of the nanotubes and to allow efficient dispersion in ethanol or in chitosan. Transmission electron microscopy and Raman spectroscopy suggested the removal of amorphous material and reduction of the CNT diameter as well as modifications to their defect structures. The surface oxidation was determined by FTIR spectroscopy. At longer times or higher ultrasound intensities, degradation such as nanotube shortening and additional defect generation in the graphitic network occurred and the benefits of using ultrasound decreased. The modified CNTs were used as fillers for chitosan films and gave a tenfold increase in tensile strength and integrity of the films. The methodology was combined with sonochemical generation of gold or iron oxide nanoparticles to produce a range of functional membranes for catalytic reductive hydrogenation or dye degradation under conditions that are more environmentally benign than those previously used. Our results further add to the usefulness of sonochemistry as a valuable tool in preparative materials chemistry but also illustrate the crucial importance of careful control over the experimental conditions if optimum results are to be obtained.

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“…Longer treatment, even at the same intensity, causes significant breakage of CNTs and mechanical damage to their surface. Cavitation also produces a large degree of turbulence and the motion and hence high shear forces generated in the fluid could break [18] the CNTs, leading to more open ends. This can be seen when a higher ultrasound intensity was used (SH30, Fig 4(d) inset).…”

Section: Structural Evolution During Sonochemical Treatmentmentioning

confidence: 99%

“…To illustrate its potential, some years ago Yang et al suggested that ultrasound-assisted functionalization methods might replace conventional acid treatments opening up the possibility of more efficient and cleaner treatment methods [17]. Tian and co-workers also showed that sonication could speed up permanganate oxidation and increase the number of oxygen-containing functional groups at the surface [18]. In further studies, Ng and Manickam demonstrated [19] that the extent of surface reaction could be controlled by varying the sonication time and Huang et al indicated that ultrasound could be used to vary the mean length of the CNTs as well as to prepare the surface for further reaction with a polymer [20].…”

Section: Introductionmentioning

confidence: 99%

Comparative study of the modification of multi-wall carbon nanotubes by gamma irradiation and sonochemically assisted acid etching

Bibi

Yasin

Nawaz

et al. 2018

Materials Chemistry and Physics

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Comparatively studying the ultrasound present in a mild two-stage approach on the content of functional groups in modified MWCNT

Cited by 9 publications

References 24 publications

Acetylation Strategy for Unzipping Carbon Nanotubes in High-Performance Lithium-Ion Batteries

Acetylation Strategy for Unzipping Carbon Nanotubes in High-Performance Lithium-Ion Batteries

Sonochemical modification of carbon nanotubes for enhanced nanocomposite performance

Comparative study of the modification of multi-wall carbon nanotubes by gamma irradiation and sonochemically assisted acid etching

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