HRTEM low dose: the unfold of the morphed graphene, from amorphous carbon to morphed graphenes

Abstract

We present experimental evidence under low-dose conditions transmission electron microscopy for the unfolding of the evolving changes in carbon soot during mechanical milling. The milled soot shows evolving changes as a function of the milling severity or time. Those changes are responsible for the transformation from amorphous carbon to graphenes, graphitic carbon, and highly ordered structures such as morphed graphenes, namely Rh6 and Rh6-II. The morphed graphenes are corrugated layers of carbon with cross-linked covalently nature and sp2- or sp3-type allotropes. Electron microscopy and numerical simulations are excellent complementary tools to identify those phases. Furthermore, the TEAM 05 microscope is an outstanding tool to resolve the microstructure and prevent any damage to the sample. Other characterization techniques such as XRD, Raman, and XPS fade to convey a true identification of those phases because the samples are usually blends or mixes of the mentioned phases.

N-Doped few-layer graphene encapsulated Pt-based bimetallic nanoparticles via solution plasma as an efficient oxygen catalyst for the oxygen reduction reaction

“…The lattice fringes of thin layers revealed double layers with d-spacing of approximately 0.34 nm, which corresponded to that of a few layers graphene that was previously reported. 29 This coating has been reported that it helps in stabilizing the structure of the metal core, which enhances the durability of the metal catalyst. 30 Besides, it was also reported that the heteroatomcontaining carbon-shell, on metals enhanced the electrical conductivity, leading to the promotion of the catalytic activity.…”

Mesoporous onion-like carbon nanostructures from natural oil for high-performance supercapacitor and electrochemical sensing applications: Insights into the post-synthesis sonochemical treatment on the electrochemical performance

“…Upon sonication, an increase in the intensity of the D and D′ bands is observed in the OLCs, implying an increase in the concentration of defects. The occurrence of D** band confirms the presence of amorphous carbon and different functional moieties in OLCs [28] , [29] , [30] . D* band, the lower energy shoulder of the D band is due to the sp 2 -sp 3 disordered graphitic lattice of the OLCs.…”

Gram‐Scale Bottom‐Up Synthesis of Macrographene

“…Few mono crystalline large sheets were also observed suggesting loss of crystallinity with increase in size of the sheets. The FFT analysis shows 6‐fold reflection spots which confirm hexagonal crystal lattice for graphene sheets with an in‐plane lattice spacing of approximately 3.1 Å, corresponding to the reflection from (002) plane …”

“…The CAP was subjected to Scholl oxidation in 2:1 AlCl 3 ‐NaCl melt at 165 °C for 6 h. The reaction mixture was quenched with water and worked up to get MG in good yields (see supporting information (SI) for details of synthesis). We have applied a variety of techniques (FTIR, UV‐Vis, XPS, Raman, XRD, TEM and AFM) for characterization of the product, and the data obtained were compared with literature to confirm our assignment of the product as graphene sheets.…”