Laser modification of optical properties of a carbon nanotube suspension in dimethylformamide

Mikheev, G. M.; Kuznetsov, V. L.; Mikheev, K. G.; Mogileva, T. N.; Shuvaeva, M. A.; Мосеенков, С. И.

doi:10.1134/s1063785013040093

Cited by 20 publications

(10 citation statements)

References 15 publications

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“…The microstructure of the prepared materials was analyzed by HRTEM, using a JEM‐2010 microscope (JEOL). The samples were dispersed in dimethylformamide, drop cast onto a micromesh copper grid and transferred to the vacuum chamber where the solvent was evaporated. The microscope was operated at an accelerating voltage of 200 kV (nominal resolution 1.4 Å).…”

Section: Methodsmentioning

confidence: 99%

Trimetallic Mn‐Fe‐Ni Oxide Nanoparticles Supported on Multi‐Walled Carbon Nanotubes as High‐Performance Bifunctional ORR/OER Electrocatalyst in Alkaline Media

Morales

Kazakova

Dieckhöfer

et al. 2019

Adv Funct Materials

235

151

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Discovering precious metal-free electrocatalysts exhibiting high activity and stability toward both the oxygen reduction (ORR) and the oxygen evolution (OER) reactions remains one of the main challenges for the development of reversible oxygen electrodes in rechargeable metal-air batteries and reversible electrolyzer/fuel cell systems. Herein, a highly active OER catalyst, Fe 0.3 Ni 0.7 O X supported on oxygen-functionalized multi-walled carbon nanotubes, is substantially activated into a bifunctional ORR/OER catalyst by means of additional incorporation of MnO X . The carbon nanotube-supported trimetallic (Mn-Ni-Fe) oxide catalyst achieves remarkably low ORR and OER overpotentials with a low reversible ORR/ OER overvoltage of only 0.73 V, as well as selective reduction of O 2 predominantly to OH − . It is shown by means of rotating disk electrode and rotating ring disk electrode voltammetry that the combination of earthabundant transition metal oxides leads to strong synergistic interactions modulating catalytic activity. The applicability of the prepared catalyst for reversible ORR/OER electrocatalysis is evaluated by means of a fourelectrode configuration cell assembly comprising an integrated two-layer bifunctional ORR/OER electrode system with the individual layers dedicated for the ORR and the OER to prevent deactivation of the ORR activity as commonly observed in single-layer bifunctional ORR/OER electrodes after OER polarization.

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Section: Methodsmentioning

confidence: 99%

Trimetallic Mn‐Fe‐Ni Oxide Nanoparticles Supported on Multi‐Walled Carbon Nanotubes as High‐Performance Bifunctional ORR/OER Electrocatalyst in Alkaline Media

Morales

Kazakova

Dieckhöfer

et al. 2019

Adv Funct Materials

235

151

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“…Carbon nanotubes (CNTs) are among the key nanostructures that have been actively developed and investigated during the last two decades due to their unique electrophysical properties, such as high electrical and thermal conductivity, high mechanical strength, relative chemical inertness, the ability to absorb electromagnetic radiation over a wide range of wavelengths, etc. CNTs are considered as promising candidates for many potential applications such as nanocomposite materials, catalyst and catalyst supports, field emitters, sensors, energy storage devices, hydrogen storage, fuel cells, nanoelectronics, bionanomaterials, and nanomedicine . Generally, most of multi‐walled carbon nanotubes (MWCNTs) are used to improve the physical and chemical characteristics of numerous composite materials based on polymeric, metal and oxide matrices .…”

Section: Introductionmentioning

confidence: 99%

Fe–Mo and Co–Mo Catalysts with Varying Composition for Multi‐Walled Carbon Nanotube Growth

Kazakova

Кузнецов

Bokova‐Sirosh

et al. 2017

Physica Status Solidi (b)

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The formation of active component of Fe-Mo and Co-Mo catalysts for carbon nanotube growth with variable Mo content is studied with in situ XRD, XPS, and STEM&EDX. The activation of bimetallic Fe-Mo catalysts under the growth conditions leads to the formation of Fe-Mo alloy particles in contrast to Co-containing catalysts in which active alloy incorporates only a small portion of Mo (<2-3 at.%). The stable carbide formation for these systems is not detected. The effect of Mo content in Fe-Mo and Co-Mo catalysts on the properties of MWCNTs is additionally investigated using the Raman spectroscopy in combination with measurements of the temperature dependence of conductivity. It is shown that MWCNT defectiveness depends on the active component composition for both Fe-Mo and Co-Mo catalysts. The current carrier concentration for the MWCNTs grown on Fe-Mo catalysts slightly increases with the Mo content. The opposite effect is observed for the tubes grown on Co-Mo catalysts, showing a decrease in the current carrier concentration with the increase of Mo concentration.

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“…Mikheev et al reported that the optical properties of MWCNT suspended in DMF change significantly after laser irradiation; the suspension was bleached and its optical density reduced in a wide wavelength range from 225 to 900 nm. They showed that bleaching was due to laser stimulated chemical reactions between DMF molecules and MWCNT [33]. Concerning other nanomaterials, Usui et al reported that fragmented TiO nanoparticles showed higher transmittance in the visible region compared with the non-fragmented ones [12].…”

Section: Optical Propertiesmentioning

confidence: 99%

“…Literature indicates that over-exposition to laser beam results in the modification of the firstly produced nanostructures. For example, Mikheev et al [33] reported that photochemical reactions occurring between MWCNT and DMF lead to the formation of new chemical bonds, absent in the initial suspension, besides of impurities and a large number of defects in the nanotubes. Also, Hu et al [9] showed that when a single carbon black particle is heated by a laser beam, only neighboring graphitic segments within a particle bond grow, which favors the formation of large carbon nanocages.…”

Section: Morphologymentioning

confidence: 99%

“…For the best of our knowledge, the only report on the use of LFS technique for the modification of CNT in suspension deals with the bleaching of an SWCNT/DMF solution after its irradiation with ns laser pulse [33]. Herein, we report on the laser pulse effect using as the target chemically modified multi-walled carbon nanotubes (MWCNT) suspended in tetrahydrofuran (THF).…”

Section: Introductionmentioning

confidence: 99%

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Optical properties of carbon nanostructures produced by laser irradiation on chemically modified multi-walled carbon nanotubes

Vigueras-Santiago

López

Camacho-López

et al. 2016

Optics & Laser Technology

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This research focused on the nanosecond (Nd: YAG-1064 nm) laser pulse effect on the optical and morphological properties of chemically modified multi-walled carbon nanotubes (MWCNT). Two suspensions of MWCNT in tetrahydrofuran (THF) were prepared, one was submitted to laser pulses for 10 min while the other (blank) was only mechanically homogenized during the same time. Following the laser irradiation, the suspension acquired a yellow-amber color, in contrast to the black translucent appearance of the blank. UV-vis spectroscopy confirmed this observation, showing the blank a higher absorption. Additionally, photoluminescence measurements exhibited a broad blue-green emission band both in the blank and irradiated suspension when excited at 369 nm, showing the blank a lower intensity. However, a modification in the excitation wavelength produced a violet to green tuning in the irradiated suspension, which did not occur in the blank. Lastly, the electron microscopy analysis of the treated nanotubes showed the abundant formation of amorphous carbon, nanocages, and nanotube unzipping, exhibiting the intense surface modification produced by the laser pulse. Nanotube surface modification and the coexistence with the new carbon nanostructures were considered as the conductive conditions for optical properties modification.

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Laser modification of optical properties of a carbon nanotube suspension in dimethylformamide

Cited by 20 publications

References 15 publications

Trimetallic Mn‐Fe‐Ni Oxide Nanoparticles Supported on Multi‐Walled Carbon Nanotubes as High‐Performance Bifunctional ORR/OER Electrocatalyst in Alkaline Media

Trimetallic Mn‐Fe‐Ni Oxide Nanoparticles Supported on Multi‐Walled Carbon Nanotubes as High‐Performance Bifunctional ORR/OER Electrocatalyst in Alkaline Media

Fe–Mo and Co–Mo Catalysts with Varying Composition for Multi‐Walled Carbon Nanotube Growth

Optical properties of carbon nanostructures produced by laser irradiation on chemically modified multi-walled carbon nanotubes

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