scholarly journals Dopamine-derived nitrogen-doped carboxyl multiwalled carbon nanotube-modified graphite felt with improved electrochemical activity for vanadium redox flow batteries

2020 ◽  
Vol 7 (7) ◽  
pp. 200402
Author(s):  
Qiang Li ◽  
Anyu Bai ◽  
Tianyu Zhang ◽  
Song Li ◽  
Hong Sun
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Synergetic Effect ◽  
Electrochemical Activity ◽  
Vanadium Redox Flow Battery ◽  
Multiwalled Carbon ◽  
Graphite Felt ◽  
Nitrogen Doped ◽  
Effect Of Oxygen ◽  
Vanadium Redox

Improving the electrochemical activity of electrodes is essential to the development of vanadium redox flow battery (VRFB). In this work, we prepared a novel electrode with the modification of nitrogen-doped carboxyl multiwalled carbon nanotubes using dopamine as an eco-friendly nitrogen source (carboxyl MWCNT@PDAt). Characterization and electrochemical measurements reveal that the synthesized carboxyl MWCNT@PDAt-modified graphite felt electrode (carboxyl MWCNT@PDAt/GF) exhibits excellent electrochemical performance toward VO 2+ / V O 2 + reaction. Superior battery performance was obtained with the energy efficiency of 80.54% at a current density of 80 mA cm −2 . Excellent durability of the carboxyl MWCNT@PDAt/GF electrode was confirmed by long-term charge/discharge tests. The enhanced reaction kinetics of VO 2+ / V O 2 + is ascribed to the synergetic effect of oxygen and nitrogen containing groups on graphite felt surface and the presence of nitrogen-doped carboxyl multiwalled carbon nanotubes (MWCNT). The facile approach proposed in this paper provides a new route to the fabrication of electrode with excellent performance for VRFB.

scholarly journals A Comprehensive Study on Hydroxyl Multiwalled Carbon Nanotubes Used as Catalysts for VO2+/VO2+ Reaction in Vanadium Redox Flow Battery

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Qiang Li ◽  
Anyu Bai ◽  
Zeqiang Qu ◽  
Tianyu Zhang ◽  
Jie Li ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Cell Performance ◽  
Vanadium Redox Flow Battery ◽  
High Catalytic Activity ◽  
Redox Flow Battery ◽  
Flow Battery ◽  
Multiwalled Carbon ◽  
Vanadium Redox ◽  
Comprehensive Study

A comprehensive study on the hydroxyl multiwalled carbon nanotubes (hydroxyl MWCNTs) as catalysts in a positive reaction was performed to improve the efficiency of the vanadium redox flow battery (VRFB). The physicochemical properties of the hydroxyl MWCNT-modified electrode were characterized by using a scanning electron microscope (SEM), conductivity measurement, Brunner–Emmet–Teller (BET) measurement, X-ray photoelectron spectroscopy (XPS) analysis, cyclic voltammetry (CV) tests, electrochemical impedance spectroscopy (EIS) analysis, and charge-discharge tests. The prepared composite electrode possesses a huge amount of oxygen-containing groups, high-specific surface area, high electrical conductivity, and high catalytic activity towards the VO2+/VO2+ reaction based on physicochemical characterization. The hydroxyl MWCNT-modified graphite felt (hydroxyl MWCNTs/GF) shows the best cell performance with the energy efficiency of 79.74% and remains in high stability after 50 cycles. The improved cell performance is probably ascribed to the increase in active sites, fast charge transfer, and mass transfer rate of the introduced hydroxyl MWCNTs.

Carbon sponge-type nanostructures based on coaxial nitrogen-doped multiwalled carbon nanotubes grown by CVD using benzylamine as precursor

Carbon ◽  
2017 ◽  
Vol 115 ◽  
pp. 409-421 ◽  
Author(s):  
Emilio Muñoz-Sandoval ◽  
Alejandro J. Cortes-López ◽  
Beatriz Flores-Gómez ◽  
Juan L. Fajardo-Díaz ◽  
Roque Sánchez-Salas ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Multiwalled Carbon ◽  
Nitrogen Doped

Synthesis and characterization of multiwalled carbon nanotubes-protoporphyrin IX composites using acid functionalized or nitrogen doped carbon nanotubes

2016 ◽  
Vol 70 ◽  
pp. 65-75 ◽  
Author(s):  
Miriam M. Tostado-Plascencia ◽  
Marciano Sanchez-Tizapa ◽  
Adalberto Zamudio-Ojeda ◽  
Amaury Suárez-Gómez ◽  
Rocío Castañeda-Valderrama ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Protoporphyrin Ix ◽  
Synthesis And Characterization ◽  
Multiwalled Carbon ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon

Tailoring the Seebeck Coefficient of Spray-Coated Poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonate) Films with Nitrogen Doped Multiwalled Carbon Nanotubes

2020 ◽  
Vol 20 (6) ◽  
pp. 3576-3581
Author(s):  
Ruben Sarabia-Riquelme ◽  
Camila Gomez ◽  
Dali Qian ◽  
John Craddock ◽  
Matthew Weisenberger
Keyword(s):  
Carbon Nanotubes ◽  
Seebeck Coefficient ◽  
Multiwalled Carbon Nanotubes ◽  
Thermoelectric Properties ◽  
Composite Films ◽  
Spray Coating ◽  
Multiwalled Carbon ◽  
Nitrogen Doped ◽  
Mwcnt Concentration ◽  
Polyethylene Terephthalate Substrate

The thermoelectric properties of flexible thin films fabricated from two commercial poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) formulations filled with multiwalled carbon nanotubes (MWCNT) and nitrogen-doped MWCNT (N-MWCNT) were investigated. A simple spray-coating method for the fabrication of such flexible films on a polyethylene terephthalate substrate was developed. While increasing the MWCNT concentration had little effect on the thermoelectric properties, increasing the N-MWCNT concentration resulted in the emergence of an overall n-type semiconducting behavior and, thereby, tailoring the Seebeck coefficient of the composite films from p-type to n-type was shown. The Seebeck coefficient of the two PEDOT:PSS formulation films was inverted from 4.1 to −13.3 μV/K and from 12.5 to −10.9 μV/K respectively, with increasing N-MWCNT concentration from 0 to 95 wt.%. The importance of these results for future work stems from the possibility of tailoring the behavior of a typical p-type polymer such as PEDOT:PSS and the effect that the polymer conductive grade has on the switching concentration.

Influence of growth temperature on the structure, composition and bonding character of nitrogen-doped multiwalled carbon nanotubes

2011 ◽  
Vol 26 (3) ◽  
pp. 443-448 ◽  
Author(s):  
Yu Zhang ◽  
Lujun Pan ◽  
Bin Wen ◽  
Xiaoyang Song ◽  
Chenguang Liu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Growth Temperature ◽  
Multiwalled Carbon ◽  
Nitrogen Doped ◽  
Image Position

Abstract

scholarly journals Nitrogen-Doped Multiwalled Carbon Nanotubes Inhibit Fat Deposition via Immunomodulatory Actions

2021 ◽  
Author(s):  
Haifang Li ◽  
Xue Xiao ◽  
Geng Hu ◽  
Dalin He ◽  
Wenqian Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Mammalian Cells ◽  
Fat Metabolism ◽  
Fat Deposition ◽  
The Body ◽  
Inflammatory Factors ◽  
Multiwalled Carbon ◽  
Nitrogen Doped

Abstract Multiwalled carbon nanotubes (MWCNTs) offer immense opportunities to deliver drug and biomolecules to targeted tissues. However, it’s unclear for us about their effects on fat metabolism. Here, we demonstrate that nitrogen-doped carboxylate-functionalized MWCNTs (N-MWCNTs) inhibit fat deposition both in vivo and in vitro primarily by suppressing adipogenesis. N-MWCNTs show good biocompatability in HEK293 mammalian cells. Intramuscular administration of N-MWCNTs does not affect the body weight gain and feed intake of mice, but reduces the fat mass. In in vitro-cultured adipocytes, N-MWCNTs suppress fat accumulation, accompanying with decreased and increased expression of adipogenic and lipolysis genes, respectively. Transcriptome analysis further certified the N-MWCNT alteration of fat metabolism-related genes. Interestingly, we observed the phagocytosis of N-MWCNTs by macrophage-like cells via TEM imaging. The mRNA sequencing data also showed remarkable variation of the genes involved in TLRs pathway, ultimately leading to down- or up-regulation of inflammatory factors, of which Tnfα, Il1, Il7, Il10, and Il12 are decreased, whereas Il6 and Il11 are increased. In conclusion, N-MWCNTs induce the production of inflammatory cytokines through immune responses, which trigger the reduction of fat deposition. These findings support the usage of N-MWCNTs as a promising delivery for anti-obesity agents.

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