Conversion of conducting polypyrrole nanostructures to nitrogen-containing carbons and its impact on the adsorption of organic dye

Stejskal, Jaroslav; Kohl, Miroslav; Trchová, Miroslava; Kolská, Zdeňka; Pekárek, Michal; Křivka, Ivo; Prokeš, Ján

doi:10.1039/d0ma00730g

Cited by 26 publications

(37 citation statements)

References 48 publications

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“…Such synergistic effect can again be explained by the improved brush‐like ordering of the polymer chains deposited at the substrate surface 33–35 compared with disordered form in the globules. Please note that the formation of nanotubes can also be regarded as the surface coating of the template afforded, for example, by some dyes 3 and, for that reason, the nanotubes may have better chain‐ordering and consequent higher conductivity 36 or dye adsorption 18,37 compared with the common globular form.…”

Section: Resultsmentioning

confidence: 99%

“…In order to make more general conclusions, an additional four anionic and four cationic dyes have been investigated with respect to their adsorption on the melamine sponge coated with polypyrrole nanotubes (Figure 7), which proved to be superior in the above experiments (Figure 5). The selection of anionic dyes included in addition of Reactive Black 5 also methyl red, an acidobasic indicator, Acid Blue 25 known for its ability to guide the nanofilbrilar morphology in the preparation of polypyrrole, 18 and metanil yellow used to brighten the color of turmeric. The set is completed by methyl orange, which has a special role in polypyrrole chemistry.…”

Section: Resultsmentioning

confidence: 99%

“…Although polypyrrole and its composites have been tested for dye adsorption, 3,17 polypyrrole nanotubes have been investigated for this purpose only recently 18–20 . They were also used for the removal of inorganic pollutants, such as Cr(VI) ions 21,22 .…”

Section: Introductionmentioning

confidence: 99%

“…Polypyrrole of any morphology is produced as an intractable powder, and the deposition on suitable carriers affording the materials properties is required by the particular application. A commercial macroporous open‐cell melamine/formaldehyde sponge (Figure 1b) coated with polypyrrole nanotubes or nanotubes alone have already proved to be useful in diverse applications 17,18,23–25 . Having in mind especially the design of a potential dye adsorbent, the melamine sponge has been selected as a substrate for the deposition of polypyrrole nanotubes.…”

Section: Introductionmentioning

confidence: 99%

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Adsorption of organic dyes on macroporous melamine sponge incorporating conducting polypyrrole nanotubes

Stejskal

Pekárek

Kolská

2022

J of Applied Polymer Sci

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The macropores of melamine sponge were coated with globular polypyrrole or polypyrrole nanotubes. The resulting materials have been tested for the adsorptive removal of organic dyes from aqueous medium. The nanotubes deposited on the sponge were able to remove Reactive Black 5 dye while the adsorption on analogous polypyrrole globules was marginal. For that reason, the macroporous open‐cell melamine sponge with embedded nanotubes was tested for the adsorption of five anionic and five cationic dyes. The anionic dyes were adsorbed efficiently in the contrast to cationic ones. This can be explained by the electrostatic interaction of anionic dyes with polypyrrole polycation. The fast‐starting adsorption occurred within a few minutes and was followed by a slower process extending for days. The nanotubes deposited on the sponge have always been more efficient adsorbents than free polypyrrole nanotubes or melamine sponge alone. Better organization of polymer chains in the polypyrrole nanotubes and especially those deposited on the melamine sponge is proposed to be responsible for this effect. Cationic dyes were adsorbed even by neat melamine sponge while the adsorption by polypyrrole was negligible. In this case, the indifferent role of polypyrrole can be assigned to the electrostatic repulsion of the dye.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Adsorption of organic dyes on macroporous melamine sponge incorporating conducting polypyrrole nanotubes

Stejskal

Pekárek

Kolská

2022

J of Applied Polymer Sci

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“…In experiments, the deprotonation of PPy materials generally occurs at 450–600 K [ 63 ], and the critical temperature of the pyrolysis reaction is usually 1200 K [ 19 ]. It should be noted that the theoretical critical temperature is higher than the one monitored in experiments.…”

Section: Resultsmentioning

confidence: 99%

Microstructure Evolution and Its Correlation with Performance in Nitrogen-Containing Porous Carbon Prepared by Polypyrrole Carbonization: Insights from Hybrid Calculations

Bian

et al. 2022

Materials

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The preparation of nitrogen-containing porous carbon (NCPC) materials by controlled carbonization is an exciting topic due to their high surface area and good conductivity for use in the fields of electrochemical energy storage and conversion. However, the poor controllability of amorphous porous carbon prepared by carbonization has always been a tough problem due to the unclear carbonation mechanism, which thus makes it hard to reveal the microstructure–performance relationship. To address this, here, we comprehensively employed reactive molecular dynamics (ReaxFF-MD) simulations and first-principles calculations, together with machine learning technologies, to clarify the carbonation process of polypyrrole, including the deprotonation and formation of pore structures with temperature, as well as the relationship between microstructure, conductance, and pore size. This work constructed ring expressions for PPy thermal conversion at the atomic level. It revealed the structural factors that determine the conductivity and pore size of carbonized products. More significantly, physically interpretable machine learning models were determined to quantitatively express structure factors and performance structure–activity relationships. Our study also confirmed that deprotonation preferentially occurred by desorbing the dihydrogen atom on nitrogen atoms during the carbonization of PPy. This theoretical work clearly reproduces the microstructure evolution of polypyrrole on an atomic scale that is hard to do via experimentation, thus paving a new way to the design and development of nitrogen-containing porous carbon materials with controllable morphology and performance.

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Relation between half‐cell and fuel cell activity and stability of FeNC catalysts for the oxygen reduction reaction

Scharf

Kübler

Gridin

et al. 2022

SusMat

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FeNC catalysts are promising substitutes of platinum-type catalysts for the oxygen reduction reaction (ORR). While previous research disclosed that high pyrolysis temperatures are required to achieve good stability, it was identified that a trade-off needs to be made regarding the active site density. The central question is, if a good stability can also be reached at milder pyrolysis conditions but longer duration retaining more active sites, while enabling the defect-rich carbon to heal during a long residence time? To address this, a variation of pyrolysis temperatures and durations is used in FeNC fabrication. Carbon morphology and iron species are characterized by Raman spectroscopy and Mössbauer spectroscopy, respectively. Fuel cell (FC) activity and stability data are acquired. The results are compared to ORR activity and selectivity data from rotating ring disc electrode experiments and resulting durability in accelerated stress tests mimicking the load cycle and start-up and shut-down cycle conditions. It is discussed how pyrolysis temperature and duration affect FC activity and stability. But, more important, the results connect the pyrolysis conditions to the required accelerated stress test protocol combination to enable a prediction of the catalyst stability in fuel cells.

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Conversion of conducting polypyrrole nanostructures to nitrogen-containing carbons and its impact on the adsorption of organic dye

Abstract: New types of materials can be produced by heating of conducting polymers to the elevated temperature. Three polypyrroles differing in morphology – globules, nanofibers, and nanotubes – were exposed to...

Cited by 26 publications

References 48 publications

Adsorption of organic dyes on macroporous melamine sponge incorporating conducting polypyrrole nanotubes

Adsorption of organic dyes on macroporous melamine sponge incorporating conducting polypyrrole nanotubes

Microstructure Evolution and Its Correlation with Performance in Nitrogen-Containing Porous Carbon Prepared by Polypyrrole Carbonization: Insights from Hybrid Calculations

Relation between half‐cell and fuel cell activity and stability of FeNC catalysts for the oxygen reduction reaction

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