Investigation of defects generated in vertically oriented graphene

Quinlan, Ronald A.; Cai, Meng‐Ting; Outlaw, R. A.; Butler, Sue M.; Miller, John R.; Mansour, A. N.

doi:10.1016/j.carbon.2013.07.040

Cited by 50 publications

(43 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, the O/C ratio of the fresh samples is 5.5%, as compared to 19.5% in the aged CNW. The chemical composition of our aged CNW layers is in agreement with previously reported results and the fitting procedure was carried out in the same manner as for other similar materials: carbon nanowalls, nanoflakes, nanosheets, and vertical graphene …”

Section: Resultssupporting

confidence: 86%

“…Taking into consideration all the observations and the above results, the transformations related to aging of CNW samples can be explained as follows: at the edges of fresh CNW, there are intrinsic defects, trapping locally electrical charges which favor the incorporation of oxygen and hydroxyl radicals from the environment . We believe that in our case, the healing of defects occurs in time.…”

Section: Resultsmentioning

confidence: 62%

See 1 more Smart Citation

Aging phenomena and wettability control of plasma deposited carbon nanowall layers

Vizireanu

Ionita

et al. 2017

Plasma Process Polym

View full text Add to dashboard Cite

This paper reports on the aging of carbon nanowalls (CNW) and modification of their wettability by the storage time, growth conditions, and post‐fabrication plasma treatments. The as‐deposited CNW initially exhibit marked hydrophilic behavior (fresh CNW), but within a few days they become highly hydrophobic (aged CNW). Their final hydrophobicity is closely related to their topography which is controlled by the deposition parameters. In addition, subsequent fluorinated plasma treatments result in super‐hydrophobic CNW layers, irrespective of the hydrophilic or hydrophobic character of the pre‐treated samples. To explain this, we show that the CNW edges contain many defects initially, but such defects become passivated in time. As a result, the surfaces become highly hydrophobic after aging or fluorination, having inert stable terminations.

show abstract

Section: Resultssupporting

confidence: 86%

Section: Resultsmentioning

confidence: 62%

Aging phenomena and wettability control of plasma deposited carbon nanowall layers

Vizireanu

Ionita

et al. 2017

Plasma Process Polym

View full text Add to dashboard Cite

show abstract

“…The D band at ∼1350 cm −1 and G band at ∼1585 cm −1 are indexed to the disordered structure and ordered sp 2 ‐hybrid orbits of graphitized carbon, respectively ,. The intensity ratio of D band to G band ( I D / I G ) is commonly used to characterize the defect level in graphitic materials . The I D / I G was calculated to be ∼2.5 for CWF, which was closely associated with the abundance of exposed sharp edges.…”

Section: Resultsmentioning

confidence: 99%

“…In addition to the frequency response, it's highly desirable to prepare supercapacitor with wide voltage window for AC line filtering ,. Under an operating voltage of 4.0 V (Figure d), the volumetric capacitance C vol of our CWF supercapacitor is 480 mF cc −1 , which is ∼250 folds higher than that of commercial AEC device (1.88 mF cc −1 ).…”

Section: Resultsmentioning

confidence: 99%

Hierarchical, Vertically‐Oriented Carbon Nanowall Foam Supercapacitor using Room Temperature Ionic Liquid Mixture for AC Line Filtering with Ultrahigh Energy Density

Yang

et al. 2019

ChemElectroChem

View full text Add to dashboard Cite

Supercapacitors have been considered as a promising alternative of aluminum electrolytic capacitors (AECs) for AC line filtering applications. However, realizing supercapacitors with fast frequency response and superior energy density still remains an open issue. Herein, we demonstrate a hierarchical, vertically‐oriented carbon nanowall foam (CWF) supercapacitor using mixed room temperature ionic liquids (RTILs) for high‐performance AC line filtering. Hierarchical CWF exhibits macrospores as electrolyte reservoirs to shorten ion transport distance, vertically‐oriented, open channels to enable fast ion diffusion and consecutive scaffolds to promote electron transfer. CWF supercapacitor using RTIL mixture realizes a recorded‐high areal energy density of 1.23 μWh cm−2 at 120 Hz (almost ∼2.0 times/∼10.0 times larger than those of organic/aqueous electrolytes, respectively) and fast frequency response (RC time constant=∼1.3 ms). More importantly, CWF supercapacitor achieves a capacitance advantage over commercial AECs up to 1,000 V, substantially larger than those reported in state‐of‐the‐art literatures (maximum of ∼250 V).

show abstract

“…We suppose that the defects (dangling bonds) are terminated with hydrogen atoms. However, well-ordered CNT and CNW contain a lower defect density [26,27] in comparison to amorphous carbon nanoparticles.…”

Section: Erda Measurementsmentioning

confidence: 99%

Morphology, Microstructure, and Hydrogen Content of Carbon Nanostructures Obtained by PECVD at Various Temperatures

Gentoiu

Betancourt-Riera

Vizireanu

et al. 2017

Journal of Nanomaterials

View full text Add to dashboard Cite

Carbon nanostructures were obtained by acetylene injection into an argon plasma jet in the presence of hydrogen. The samples were synthesized in similar conditions, except that the substrate deposition temperatures were varied, ranging from 473 to 973 K. A strong dependence of morphology, structure, and graphitization upon was found. We obtained vertical aligned carbon nanotubes (VA-CNTs) at low temperatures as 473 K, amorphous carbon nanoparticles (CNPs) at temperatures from about 573 to 673 K, and carbon nanowalls (CNWs) at high temperatures from 773 to 973 K. Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, elastic recoil detection analysis, X-ray photoelectron spectroscopy, and Raman spectroscopy were used to substantiate the differences in these material types. It is known that hydrogen concentration modifies strongly the properties of the materials. Different concentrations of hydrogen-bonded carbon could be identified in amorphous CNP, VA-CNT, and CNW. Also, the H : C ratios along depth were determined for the obtained materials.

show abstract

Investigation of defects generated in vertically oriented graphene

Cited by 50 publications

References 42 publications

Aging phenomena and wettability control of plasma deposited carbon nanowall layers

Aging phenomena and wettability control of plasma deposited carbon nanowall layers

Hierarchical, Vertically‐Oriented Carbon Nanowall Foam Supercapacitor using Room Temperature Ionic Liquid Mixture for AC Line Filtering with Ultrahigh Energy Density

Morphology, Microstructure, and Hydrogen Content of Carbon Nanostructures Obtained by PECVD at Various Temperatures

Contact Info

Product

Resources

About