Raman spectroscopy study of graphene formed by “in situ” chemical interaction of an organic precursor with a molten aluminium matrix

Abstract

A study of graphene “in situ” formed during the chemical interaction of glucose with molten aluminium under a layer of molten alkaline halides in air at temperatures of 750–850°C is presented. By means of Raman and X‐ray photoelectron spectroscopy and electron microscopy, it is shown that graphene films synthesize in the aluminium. The number and defectiveness of graphene layers inside aluminium matrix depends on synthesis temperature– at 750°C two‐layer graphene and at 850°C three‐layer graphene form. The most defective graphene films synthesized at 750°C with the formation of five‐ and seven‐membered rings in plane of the graphene grid; the number of defects of graphene films is less for composite obtained at higher temperature. The evaluated defectiveness of graphene not exceed 14%; it evidences the formation of perfect graphene in aluminium matrix. The compressive stress value is the smallest for the sample obtained at 750°C and increases with temperature and plastic deformation because of differences in the crystal lattice parameters and their thermal expansion coefficients of aluminium and graphene. This fact explains the relation of defects number in graphene with temperature and plastic deformation. No aluminium carbide and graphene oxide were formed during synthesis inside aluminium matrix because of formation of defect‐free perfect graphene with high chemical stability. The absence of aluminium carbide was proven by means Raman spectroscopy, X‐ray photoelectron, transmission electron microscopy, and corrosion test with distilled water. It allows to propose aluminium‐graphene composites for numerous practical applications as a constructive material.

Effect of Grain Size on the Properties of Aluminum Matrix Composites with Graphene

“…According to the data reported in [16][17][18][19][20], there exist various techniques of introducing carbon nanomaterials into a metal matrix: infiltration of liquid metal into the fibers [16], ball milling [17], implantation of carbon ions into the Al target [18], selective laser melting [19], SPD [20], etc. Among new experimental methods of obtaining graphenereinforced composites, one should mention the in sit synthesis of graphene nanoparticles from carbon-containing precursors directly in the metal matrix in molten salt media [21][22][23][24][25]. Among the key advantages of such a technique is the elimination of porosity, which is characteristic of composites produced ex situ, when previously obtained ultrafine nanoparticles are introduced into the metal matrix.…”

Fast-charged aluminum-ion battery with aluminum-graphene nanocomposite anode

“…1 A schematic representation and a photo of the electrochemical cell 1-working electrodes; 2-Teflon cell; 3liners for holding the electrodes and the separator; 4-electrolyte; 5-porous separator with electrolyte 1586 cm −1 ; 2D-2704 cm −1 . The intensity ratio I 2D /I G is 0.47, which implies the formation of three-layered graphene [32]. The D peak is considered to indicate the defects in the graphene layer; therefore, its low intensity confirms the formation of perfect quality graphene in the aluminum matrix.…”

Recent progress of defect chemistry on 2D materials for advanced battery anodes

“…With these two effective ways, all the information on 2D materials structure, including the electronic properties and lattice-vibrations can be extracted and exploited to survey the thickness in the case of monolayer and number of layers in the case of vdW heterostructures, biaxial and uni-axial strain, structural stability of the materials, and more especially the defects chemistry as well as a stacking orders of 2D materials. [81][82][83][84][85][86][87] Indeed, it has been recognized that Raman-spectroscopy constitutes a potential and effective way to characterize defects chemistry in 2D materials with graphene or graphene like-structure, owing to the existence of D-and D'peaks relative to defects in the spectrum of samples. [88][89][90][91] In the case of other 2D materials, namly, TMDs, there also appear some additional Raman-peaks immediately after introducing the defects chemistry with an intensity correlated to the density of the defects.…”

“…In contrast, the optical spectroscopic techniques, especially Raman and photoluminescence spectroscopies, provide an efficient and nondestructive way to characterize defect on 2D materials. With these two effective ways, all the information on 2D materials structure, including the electronic properties and lattice‐vibrations can be extracted and exploited to survey the thickness in the case of monolayer and number of layers in the case of vdW heterostructures, bi‐axial and uni‐axial strain, structural stability of the materials, and more especially the defects chemistry as well as a stacking orders of 2D materials [81–87] . Indeed, it has been recognized that Raman‐spectroscopy constitutes a potential and effective way to characterize defects chemistry in 2D materials with graphene or graphene like‐structure, owing to the existence of D‐ and D’‐peaks relative to defects in the spectrum of samples [88–91] .…”