Effects of catalyst aging on the growth morphology and oxygen reduction activity of nitrogen-doped carbon nanotubes

Bresciani, Roberto; Marzorati, Stefania; Lascialfari, A.; Sacchi, Benedetta; Santo, Nadia; Longhi, Mariangela

doi:10.1016/j.elecom.2014.12.003

Cited by 15 publications

(22 citation statements)

References 30 publications

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“…Membrane and membrane processes constitute an interdisciplinary field whose explosive evolution has been determined by the unlimited involvement of materials science, mathematics, physics, physical chemistry, biology, and engineering in every stage from theory to industrial process. A proof of this is the multiple applications in various fields such as biomedical sciences: hemodialysis [18][19][20], protein separation [21,22], osteointegration , fuel cells [26][27][28], environmental decontamination [29].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Cellulose Acetate Membranes with Self-Indicating Properties by Changing the Membrane Surface Color for Separation of Gd(III)

Serbanescu¹,

Pandele

Miculescu

et al. 2020

Coatings

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This study presents a new, revolutionary, and easy method for evaluating the separation process through a membrane that is based on changing the color of the membrane surface during the separation process. For this purpose, a cellulose acetate membrane surface was modified in several steps: initially with amino propyl triethoxysilane, followed by glutaraldehyde reaction and calmagite immobilization. Calmagite was chosen for its dual role as a molecule that will complex and retain Gd(III) and also as an indicator for Gd(III). At the contact with the membrane surface, calmagite will actively complex and retain Gd(III), and it will change the color of the membrane surface during the complexation process, showing that the separation occurred. The synthesized materials were characterized by Fourier transform infrared spectroscopy (FT-IR), thermal analysis (TGA-DTA), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy, demonstrating the synthesis of membrane material with self-indicating properties. In addition, in the separation of the Gd(III) process, in which a solution of gadolinium nitrate was used as a source and as a moderator in nuclear reactors, the membrane changed its color from blue to pink. The membrane performances were tested by Induced Coupled Plasma–Mass Spectrometry (ICP-MS) analyses showing a separation process efficiency of 86% relative to the initial feed solution.

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Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Cellulose Acetate Membranes with Self-Indicating Properties by Changing the Membrane Surface Color for Separation of Gd(III)

Serbanescu¹,

Pandele

Miculescu

et al. 2020

Coatings

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“…It has been reported in the literature that the presence of pyridinic 42,[54][55][56][57] and/or quaternary nitrogen 58,59 surface groups enhances the ORR activity of carbon electrodes. Based on XPS and ORR results, however, GH710 displays poor ORR kinetics even though it displays a higher surface density of pyridinic sites than GH900.…”

Section: 46mentioning

confidence: 99%

Template-free ultraspray pyrolysis synthesis of N/Fe-doped carbon microspheres for oxygen reduction electrocatalysis

et al. 2015

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Ultrasonic spray pyrolysis was used in a continuous flow apparatus for the template-free synthesis of ironand nitrogen-doped porous carbon materials. Solutions of glucose, histidine and Fe(CH 3 COO) 2 were nebulized and pyrolyzed yielding carbon microspheres. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Focused Ion Beam (FIB) milling revealed that microspheres initially possess empty cores and a smooth shell. Further annealing leads to a collapse of this shell, and formation of porous microspheres with high roughness and iron-rich aggregates. X-ray Diffraction (XRD) and Photoelectron Spectroscopy (XPS) were used to investigate bulk and surface chemistry: microspheres were found to undergo graphitization; Fe and Fe 3 C particles form and become encapsulated within the carbon phase, while the nitrogen present in the precursor solution results in the formation of pyridinic/pyrrolic N-centers. The microspheres were tested as electrocatalysts for the oxygen reduction reaction (ORR) in acidic solution. Polarization curves using a Rotating Disk Electrode (RDE) yielded electrocatalytic behavior, and the number of exchanged electrons n ¼ 3.7 AE 0.2 calculated from Koutecky-Levich plots suggests that direct formation of H 2 O is the preferred ORR mechanism.These results indicate that this synthetic approach offers a simple and scalable strategy for the preparation of electrode materials for polymer electrolyte membrane fuel cells.

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“…The presence of a small amount of Fe and lack of N did not lead to an increased electroactivity for the ORR, while the presence of both Fe and N atoms lead to an improved catalytic activity for ORR. Also, decreasing the N-pyridinic/pyrrolic content was found to result in a lower catalytic activity suggesting that the presence and nature of N-containing surface groups was more important in enhancing the ORR activity than the presence of metallic impurities[102].Zhong et al, have reported their studies on the usage of nitrogen doped carbon nanotubes with encapsulated ferric carbide as an excellent electrocatalyst for oxygen reduction reaction in acid and alkaline media[103]. CNTs doped with N and Fe3C nanoparticles incapsulated inside the nanotubes were synthesised by direct pyrolysis of melamine and feric chloride.…”

mentioning

confidence: 99%

“…Vertical aligned N-CNTs were found to have the highest N content 4.33-6.58wt.%. N-CNTs obtained from ethylenediamine proved to be the most electrochemically active species for the ORR reduction reaction in acid media.This very active type of catalyst possess unique properties due to the corrugated nanotubs structure with sufficient surface defects in combination with high procent of N-pyridinic and N-pyridinic oxides[101].The different effects of catalyst aging on the growth morphology and oxygen reduction activity of nitrogen-doped carbon nanotubes were also studied[102]. It was reported that the Fe/MgO used in the N-CNTs synthesis could significantly influence their activity in ORR reaction at the fuel cells cathode.…”

mentioning

confidence: 99%

Fundamentals and scopes of doped carbon nanotubes towards energy and biosensing applications

Muhulet

Miculescu

Voicu

et al. 2018

Materials Today Energy

173

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Since their first allusion, carbon nanotubes have attracted significant research interest, especially with respect to composite manufacturing as a filler material for enhancing their mechanical and electrical properties. Several methods have been developed for modifying the electrical properties of carbon nanotubes such as CNTs wall's carbon atoms substitution with other appropriate atoms including engineering of their outer surfaces by covalent and noncovalent molecules, such as CNTs channel filling and nano-chemical reactions therein. CNTs with tailored electrical conduction open large perspectives for their applicabilities in advanced technologies. Taking into consideration the innovative advantages of pure and hybrid CNTs, in this article we have comprehensively reviewed the latest state-of-art research developments in the direction of different synthesis strategies, structure-property relationships, and advanced applications towards energy storage, supercapacitors, electrodes, catalytic supports, as well as biosensing.

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Effects of catalyst aging on the growth morphology and oxygen reduction activity of nitrogen-doped carbon nanotubes

Cited by 15 publications

References 30 publications

Synthesis and Characterization of Cellulose Acetate Membranes with Self-Indicating Properties by Changing the Membrane Surface Color for Separation of Gd(III)

Synthesis and Characterization of Cellulose Acetate Membranes with Self-Indicating Properties by Changing the Membrane Surface Color for Separation of Gd(III)

Template-free ultraspray pyrolysis synthesis of N/Fe-doped carbon microspheres for oxygen reduction electrocatalysis

Fundamentals and scopes of doped carbon nanotubes towards energy and biosensing applications

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