Raman study of D* band in graphene oxide and its correlation with reduction

Lee, A Young; Yang, Kyung Chae; Anh, Nguyen Duc; Park, Chulho; Lee, Seung Mi; Lee, Tae Geol; Jeong, Mun Seok

doi:10.1016/j.apsusc.2020.147990

Cited by 291 publications

(139 citation statements)

References 45 publications

Supporting

Mentioning

111

Contrasting

Unclassified

Order By: Relevance

“…[ 7 ] The D 2 band is associated with carbon atoms around the grain boundaries of crystalline graphene, regarded as edge defects. [ 7 , 8 ] In addition, the D 3 band is related to the amorphous sp 3 carbon, the intensity of which is inversely related to G band. [ 8 , 9 ] The intensity ratios of I D1 / I G , I D2 / I G , and I D3 / I G based on peak area were shown in Figure 2d and Table S2 (Supporting Information).…”

Section: Resultsmentioning

confidence: 99%

“…[ 7 , 8 ] In addition, the D 3 band is related to the amorphous sp 3 carbon, the intensity of which is inversely related to G band. [ 8 , 9 ] The intensity ratios of I D1 / I G , I D2 / I G , and I D3 / I G based on peak area were shown in Figure 2d and Table S2 (Supporting Information). The values are found to increase first when the temperature is increased from 800 to 1000 °C, then decreased at 1100 °C, indicating that highest content of carbon defects is achieved at 1000 °C, in agreement with XRD results.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Superstructured Macroporous Carbon Rods Composed of Defective Graphitic Nanosheets for Efficient Oxygen Reduction Reaction

Wang

Zhang

et al. 2021

Advanced Science

View full text Add to dashboard Cite

Rationally designed carbon materials with superstructures are promising candidates in applications such as electrocatalysis. However, the synthesis of highly porous carbon superstructures with macropores and carbon defects from a simple crystalline solid remains challenging. In this work, superstructured macroporous carbon rods composed of defective graphitic nanosheets are synthesized by direct carbonization of crystalline poly tannic acid (PTA) rods as precursors. During carbonization, PTA rods with a highly ordered lamellar structure induce a spatially confined two-step localized contraction that takes place in different dimensions and directions in each step. The unexpected contraction behavior results in the sponge-like macroporous carbon superstructure with large surface area, high porosity, and abundant defects, thus showing a superior electrocatalytic performance with high activity and selectivity for oxygen reduction reaction. The study provides new understandings in the design of functional carbon materials with distinctive structures and applications.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Superstructured Macroporous Carbon Rods Composed of Defective Graphitic Nanosheets for Efficient Oxygen Reduction Reaction

Wang

Zhang

et al. 2021

Advanced Science

View full text Add to dashboard Cite

show abstract

“…The Raman spectra of GO and rGO showed typical D and G bands at ~1350 and ~1580 cm −1 , respectively (Figure 5d) [44]. To obtain an accurate estimation of the intensity ratio of the D peak to the G peak, I D /I G , the broad D and G bands were deconvoluted into five components, as shown in Figure 6: G (~1580 cm −1 ), D (~1350 cm −1 ), D* (~1150-1200 cm −1 ), D (~1500-1550 cm −1 ), and D (~1620 cm −1 ) [45][46][47][48]. Three pseudo-Voigt (for D, G, and D' peaks) and two Gaussian (for D* and D peaks) functions were used to fit the Raman spectra in the range of 1000-1800 cm −1 [48].…”

Section: Electrical Conductivity Of Thermally Reduced Graphene Oxide Flakesmentioning

confidence: 99%

Measurements of the Electrical Conductivity of Monolayer Graphene Flakes Using Conductive Atomic Force Microscopy

et al. 2021

View full text Add to dashboard Cite

The intrinsic electrical conductivity of graphene is one of the key factors affecting the electrical conductance of its assemblies, such as papers, films, powders, and composites. Here, the local electrical conductivity of the individual graphene flakes was investigated using conductive atomic force microscopy (C-AFM). An isolated graphene flake connected to a pre-fabricated electrode was scanned using an electrically biased tip, which generated a current map over the flake area. The current change as a function of the distance between the tip and the electrode was analyzed analytically to estimate the contact resistance as well as the local conductivity of the flake. This method was applied to characterize graphene materials obtained using two representative large-scale synthesis methods. Monolayer graphene flakes synthesized by chemical vapor deposition on copper exhibited an electrical conductivity of 1.46 ± 0.82 × 106 S/m. Reduced graphene oxide (rGO) flakes obtained by thermal annealing of graphene oxide at 300 and 600 °C exhibited electrical conductivities of 2.3 ± 1.0 and 14.6 ± 5.5 S/m, respectively, showing the effect of thermal reduction on the electrical conductivity of rGO flakes. This study demonstrates an alternative method to characterizing the intrinsic electrical conductivity of graphene-based materials, which affords a clear understanding of the local properties of individual graphene flakes.

show abstract

“…The D* is known to be in connection with sp 3 orbitals in disordered amorphous carbon [ 33 ] and nanocrystalline diamond [ 34 ]. The D* was also observed in graphene oxide where vibration restrictions were posed by the presence of oxygen-containing groups [ 35 ] and few-layer wrinkled graphene (FLwG) [ 36 ]. However, both bands were postulated by Ferarri et al [ 34 ] to be in connection with sp 2 -bonded configurations of transpolyacetylene segments at grain boundaries and surfaces of CVD carbon.…”

Section: Resultsmentioning

confidence: 99%

Thermal Transport and Thermoelectric Effect in Composites of Alumina and Graphene-Augmented Alumina Nanofibers

et al. 2021

View full text Add to dashboard Cite

The remarkable tunability of 2D carbon structures combined with their non-toxicity renders them interesting candidates for thermoelectric applications. Despite some limitations related to their high thermal conductivity and low Seebeck coefficients, several other unique properties of the graphene-like structures could out-weight these weaknesses in some applications. In this study, hybrid structures of alumina ceramics and graphene encapsulated alumina nanofibers are processed by spark plasma sintering to exploit advantages of thermoelectric properties of graphene and high stiffness of alumina. The paper focuses on thermal and electronic transport properties of the systems with varying content of nanofillers (1–25 wt.%) and demonstrates an increase of the Seebeck coefficient and a reduction of the thermal conductivity with an increase in filler content. As a result, the highest thermoelectric figure of merit is achieved in a sample with 25 wt.% of the fillers corresponding to ~3 wt.% of graphene content. The graphene encapsulated nanofibrous fillers, thus, show promising potential for thermoelectric material designs by tuning their properties via carrier density modification and Fermi engineering through doping.

show abstract

Raman study of D* band in graphene oxide and its correlation with reduction

Cited by 291 publications

References 45 publications

Superstructured Macroporous Carbon Rods Composed of Defective Graphitic Nanosheets for Efficient Oxygen Reduction Reaction

Superstructured Macroporous Carbon Rods Composed of Defective Graphitic Nanosheets for Efficient Oxygen Reduction Reaction

Measurements of the Electrical Conductivity of Monolayer Graphene Flakes Using Conductive Atomic Force Microscopy

Thermal Transport and Thermoelectric Effect in Composites of Alumina and Graphene-Augmented Alumina Nanofibers

Contact Info

Product

Resources

About