Influence of temperature and point defects on the X-ray diffraction pattern of graphite

Phillips, Rhiannon; Jolley, Kenny; Zhou, Ying; Smith, Roger

doi:10.1016/j.cartre.2021.100124

Cited by 29 publications

(16 citation statements)

References 32 publications

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“…49 Å and 2.48 Å for V2G, NSV2G, K-V2G, and K-NSV2G, respectively. This result is in good agreement with the experimental study, mostly analyzed using X-ray and neutron diffraction the lattice vector was reported as 2.43 Å and 2.5 Å for vacant defect and doped graphene, respectively (Krishna et al, 2017;Phillips et al, 2021;Sheka et al, 2015). The divacancy graphene loses the symmetry near the vacant site, and the two opposite C-C which were connected to the same C atoms before being removed has a shortened distance of 2.06 Å than in pristine graphene (~2.46 Å) (Yin et al, 2014).…”

Section: Resultssupporting

confidence: 91%

Does Divacancy Defect Combine with N,S-Codoping Enhance the Electronic Properties of Graphene to Its Interaction with K+ Ion?

Hidayat

Rahmawati

Nugrahaningtyas

et al. 2023

molekul

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Defects in graphene alter its structure, electrical characteristics, and interaction with K+ ions. The related characteristics of divacancy defect graphene and N, S codoped divacancy graphene were effectively explored using the DFTB technique. Divacancy is essential for the band gap opening. The dopants considerably enhance the density of state (DOS) intensity and alter the graphene-character bands. The depletion of density caused by the dopant is seen on the charge density isosurface. Because the charge of the K+ ion is balanced by the dopant, the ion prefers to be adsorbed on divacancy graphene with dopants.

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Section: Resultssupporting

confidence: 91%

Does Divacancy Defect Combine with N,S-Codoping Enhance the Electronic Properties of Graphene to Its Interaction with K+ Ion?

Hidayat

Rahmawati

Nugrahaningtyas

et al. 2023

molekul

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show abstract

“…However, there is a slight blue shift and broadening from graphite to FG6 in the (002) and (004) planes. The peak shifted from 2θ ≈ 26.66 to 25.97° for the (002) plane and from 2θ ≈ 55.19 to 54.73° for the (004) plane after the functionalization of graphite, attributed to lattice strain caused by functional group substitutions in graphite . SEM was also used to compare the bulk structures of graphite and FG6 (Figure e,f), showing no major differences on the micron scale.…”

Section: Resultsmentioning

confidence: 99%

“…19 to 54.73°for the (004) plane after the functionalization of graphite, attributed to lattice strain caused by functional group substitutions in graphite. 28 SEM was also used to compare the bulk structures of graphite and FG6 (Figure 2e,f), showing no major differences on the micron scale. Acid functionalization of graphite to FG6 improves the material's dispersibility in isopropanol, which is important for producing uniform films when using the drop-casting method.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Tuning the Functionalization of Graphite for Hydrovoltaic Power Generation

Kumar

Kay

Beaton

et al. 2023

ACS Appl. Mater. Interfaces

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The recent discovery of hydrovoltaic devices for power generation has led to a rapid growth into new materials for harvesting energy specifically for this research field. Of the materials investigated, carbon materials have dominated, and graphene oxide (GO) has emerged as the leader. While graphite is conductive, it does not have functional groups to strongly interact with water, and highly functionalized GO forms strong interaction with water to generate necessary surface charges but does not typically have high conductivity. Herein, we report the fabrication and functionalization of a graphite-based structure, controlling the extent of oxidation to balance the effects of conductivity and functionalization to achieve high power outputs in hydrovoltaics. Devices prepared using the functionalized graphite achieve a power output of 53.3 μW/g. High power output and good film stability are key advances toward the practical application of hydrovoltaic devices for renewable energy.

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“…After aging Ni-based catalysts with water vapor at high temperatures, the XRD characteristic peaks of Ni move slightly to the left, while the peak positions of the other species remain unchanged. This is because Ni particles are slightly oxidized after water vapor treatment, crystal lattice distortion occurs on the surface, and the crystal lattice constant increases, resulting in a slight shift in the characteristic peaks of Ni . This suggests that the steam treatment will cause part of metallic Ni particles to be oxidized to NiO, and also some ZnAl 2 O 4 is transformed into the NiAl 2 O 4 phase.…”

Section: Resultsmentioning

confidence: 99%

“…This is because Ni particles are slightly oxidized after water vapor treatment, crystal lattice distortion occurs on the surface, and the crystal lattice constant increases, resulting in a slight shift in the characteristic peaks of Ni. 34 This suggests that the steam treatment will cause part of metallic Ni particles to be oxidized to NiO, and also some ZnAl 2 O 4 is transformed into the NiAl 2 O 4 phase. However, the peaks of NiO and NiAl 2 O 4 disappear again in the spent 35%Ni/ZnAl 2 O 4 catalyst (after a 10 h reaction at 450 °C), indicating that they can be readily converted back to Ni and ZnAl 2 O 4 , respectively, either upon in situ reduction (at 520 °C) or during the reaction.…”

Section: Catalytic Performance After Steam Treatmentmentioning

confidence: 99%

High-Stability ZnAl₂O₄ Spinel-Supported Nickel Catalyst for High-Temperature Syngas Methanation

Zhang,

Li,

Chen

et al. 2023

Ind. Eng. Chem. Res.

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The development of Ni-based syngas methanation catalysts with superior thermal stability remains a formidable challenge, which typically requires the use of a high Ni loading and a recipe containing very complex components. Herein, a novel Ni catalyst using a ZnAl 2 O 4 spinel support was designed and prepared by an isopropanol-mediated controlled hydrolysis method, which demonstrated excellent reactivity and stability toward the syngas methanation reaction. Moreover, the 35% Ni/ZnAl 2 O 4 catalyst still maintained a high reactivity after steam treatment at 750 °C, while the 35% Ni/Al 2 O 3 counterpart suffered a nearly complete loss of reactivity during such an accelerated test. The detailed characterization reveals that the drastic deactivation of Ni/Al 2 O 3 after steam treatment is attributed to the favored formation of NiAl 2 O 4 under the severe reaction atmosphere, resulting in the loss of active Ni. In contrast, the employment of the highly stable ZnAl 2 O 4 support can not only inhibit the sintering of supported Ni particles due to their strong interaction but also avoid the loss of the active Ni component by preventing the formation of NiAl 2 O 4 . This work sheds light on the critical role and the intrinsic mechanism of the spinel support for the construction of the desired methanation catalysts. The mechanistic scenario revealed in this work provides an important and novel solution to overcome the deactivation problem not only useful for methanation catalysts but also valid for most other supported metal catalysts commonly used in the reaction processes that require severe reaction conditions.

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Influence of temperature and point defects on the X-ray diffraction pattern of graphite

Cited by 29 publications

References 32 publications

Does Divacancy Defect Combine with N,S-Codoping Enhance the Electronic Properties of Graphene to Its Interaction with K+ Ion?

Does Divacancy Defect Combine with N,S-Codoping Enhance the Electronic Properties of Graphene to Its Interaction with K+ Ion?

Tuning the Functionalization of Graphite for Hydrovoltaic Power Generation

High-Stability ZnAl₂O₄ Spinel-Supported Nickel Catalyst for High-Temperature Syngas Methanation

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Influence of temperature and point defects on the X-ray diffraction pattern of graphite

Cited by 29 publications

References 32 publications

Does Divacancy Defect Combine with N,S-Codoping Enhance the Electronic Properties of Graphene to Its Interaction with K+ Ion?

Does Divacancy Defect Combine with N,S-Codoping Enhance the Electronic Properties of Graphene to Its Interaction with K+ Ion?

Tuning the Functionalization of Graphite for Hydrovoltaic Power Generation

High-Stability ZnAl2O4 Spinel-Supported Nickel Catalyst for High-Temperature Syngas Methanation

Contact Info

Product

Resources

About

High-Stability ZnAl₂O₄ Spinel-Supported Nickel Catalyst for High-Temperature Syngas Methanation