Catalytic graphene formation in coal tar pitch- derived carbon structure in the presence of SiO2 nanoparticles

Gubernat, Maciej; Frączek-Szczypta, Aneta; Tomala, Janusz; Błażewicz, S.

doi:10.1016/j.ceramint.2017.11.072

Cited by 12 publications

(4 citation statements)

References 24 publications

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“…In the case mentioned, low-temperature thermal annealing specifically impacts the size of carbon clusters or crystallites along the c -axis more significantly than those along the a -axis. This implies that the heat treatment has a greater effect on the arrangement and size of carbon structures in the c -axis direction compared to the a -axis direction. , Besides that, the graphite lignins used to produce GOs are of varying quality, which results in the inequivalence of nominal sheet sizes and stacking. The non-catalyzed graphite lignin spectrum had a considerably larger diffraction angle at (002), indicating a lack of graphitic lamellae development (in other words, a higher composition of disordered carbon microstructures), while the Fe-catalyzed graphite lignin spectrum showed a very indicative graphitic phase formation.…”

Section: Resultsmentioning

confidence: 99%

Structural Metamorphosis of Graphitic Derivatives Produced from Fractionated Bamboo Lignin

Ahmad Farid,

Lease,

Zheng

et al. 2023

ACS Sustainable Resour. Manage.

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The demand for sustainable and renewable materials has prompted extensive research on lignocellulosic biomass as a potential feedstock for advanced nanomaterials. This article describes the sequential processes of iron-catalyzed graphitization, improved Hummer's method, and low-temperature thermal annealing designed to transform ethanosolv lignin into bio-based graphene products. The lignin undergoes a metamorphosis during graphitization, transforming into turbostratic crystallite with a unique flake-like configuration at high temperatures in a tightly sealed muffle furnace. Following oxidation, the structure of the resultant graphite undergoes dynamic changes, leading to exfoliation-induced distancing of the sheets of graphene layers. Notwithstanding the reduction process, the geometrical morphology of its oxidized state remains unaltered, preserving the lamellar configuration. Notably, the resulting graphitized lignin showcases a substantial carbon content exceeding 75 wt % and a relatively low oxygen content below 16 wt %. In contrast, graphene oxides (GOs) exhibit elevated oxygen levels resulting from the introduction of oxygen moieties during the oxidation step, which subsequently diminishes following thermal annealing. Diffraction patterns confirm the presence of ( 001), (002), and (100) planes in all graphene-based materials, indicating an aromatic ring orientation. Oxidation affects interlayer spacing with GOs exhibiting larger distances than graphitized lignin and reduced graphene oxides (rGOs). Graphitization increases the sp 2 carbon composition by removing volatiles and mineral matter. Oxidation increases the sp 3 carbon composition, but it decreases after thermal annealing due to the partial removal of oxygen species, leading to a reorientation of the sp 2 carbon configuration.

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Section: Resultsmentioning

confidence: 99%

Structural Metamorphosis of Graphitic Derivatives Produced from Fractionated Bamboo Lignin

Ahmad Farid,

Lease,

Zheng

et al. 2023

ACS Sustainable Resour. Manage.

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“…As shown in Figure , the structure and composition of the char for EP nanocomposites were analyzed by XRD and XPS. The (002) diffraction peak of graphite (2θ = 23°) appears in the XRD spectrum of EP and its nanocomposites (Figure a), indicating that graphitized char is formed after the cone calorimetric experiment . However, the characteristic diffraction peaks of the BP crystal did not appear in the spectrum, indicating that the BP moiety in the BP and BP–NH–MCA hybrid structures completely degraded during combustion.…”

Section: Resultsmentioning

confidence: 99%

Conceptually Novel Few-Layer Black Phosphorus/Supramolecular Coalition: Noncovalent Functionalization Toward Fire Safety Enhancement

Qiu

Zhou

Xing

et al. 2021

Ind. Eng. Chem. Res.

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Black phosphorus (BP) has been widely concerned in the field of composite materials because of its special geometrical and physicochemical properties. As a red phosphorus allotrope, BP has the dual function of physical barrier and catalytic carbonization and has the potential to be a highly effective flame retardant. In this article, the aminated BP/melamine cyanurate (BP–NH–MCA) coalition with a sandwich structure was prepared by an in situ self-assembly of MCA supramolecules on the surface of aminated BP. TEM, SEM, and the surface distribution scan results showed that the hybrid nanosheets were successfully fabricated and uniformly distributed in the matrix. The analysis of the data of cone calorimetry showed that with the loading of BP–NH–MCA increasing from 0.5 to 2.0 wt %, the peak value of heat release rate of composites decreases by 21.9–47.2%, and the total heat release value decreases by 26.7–42.3%. In addition, the EP/BP–NH–MCA2.0 nanocomposite has the lowest emission intensity of typical volatile products, including toxic CO during combustion, compared to EP/BP2.0 and pure EP samples, significantly improving the fire safety of composites. This work provides a reference for the application of BP in flame-retardant fields and reveals the flame-retardant mechanism of its hybrid materials.

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“…Coal-tar pitch is an abundant and cheap natural resource which has been proposed as the carbon source for the low-cost synthesis of graphene and related materials [ 33 , 34 , 35 ]. Using coal pitch and aluminum powder as raw materials, we have prepared GNs with aluminum carbide as the intermediate by high-temperature pyrolysis and the acid pickling method [ 36 , 37 ].…”

Section: Introductionmentioning

confidence: 99%

Influence of Al-O and Al-C Clusters on Defects in Graphene Nanosheets Derived from Coal-Tar Pitch via Al4C3 Precursor

et al. 2022

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By treating Al4C3 as the precursor and growth environment, graphene nanosheets (GNs) can efficiently be derived from coal-tar pitch, which has the advantages of simple preparation process, high product quality, green environmental protection, low equipment requirements and low preparation cost. However, the defects in the prepared GNs have not been well understood. In order to optimize the preparation process, based on density functional theory calculations, the influence mechanism of Al-O and Al-C clusters on defects in GNs derived from coal-tar pitch via Al4C3 precursor has been systematically investigated. With minute quantities of oxygen-containing defects, Al-O and Al-C clusters have been realized in the prepared GNs from X-ray photoelectron spectroscopy analysis. Therefore, the influences of Al-O and Al-C clusters on graphene with vacancy defects and oxygen-containing defects are systematically explored from theoretical energy, electron localization function and charge transfer analysis. It is noted that the remaining Al-O and Al-C clusters in GNs are inevitably from the thermodynamics point of view. On the other hand, the existence of defects is beneficial for the further adsorption of Al-O and Al-C clusters in GNs.

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Catalytic graphene formation in coal tar pitch- derived carbon structure in the presence of SiO2 nanoparticles

Cited by 12 publications

References 24 publications

Structural Metamorphosis of Graphitic Derivatives Produced from Fractionated Bamboo Lignin

Structural Metamorphosis of Graphitic Derivatives Produced from Fractionated Bamboo Lignin

Conceptually Novel Few-Layer Black Phosphorus/Supramolecular Coalition: Noncovalent Functionalization Toward Fire Safety Enhancement

Influence of Al-O and Al-C Clusters on Defects in Graphene Nanosheets Derived from Coal-Tar Pitch via Al4C3 Precursor

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