Evolution in the formation of graphene nanocapsules from coal tar pitch

Abstract

It has recently been reported that coal tar pitch (CTP) can be utilised as raw material for the production of graphene nanocapsules (GNCs) because it is formed by a great quantity of aromatic organic compounds (which promote the rearrangement of double bonds by a process of polymerisation). Due to the importance of graphene and the search for a non-expensive methodology to produce it, this work used CTP to synthesise GNCs using an in situ activation technique at low temperatures and evaluating the effect of the working temperature on the formation of such nanostructures. In other words, analysing the form of the particle as the temperature rises from 600 to 900°C. As result of the experimentation, powders were obtained and analysed by the techniques of X-Ray Diffraction, Raman Spectroscopy and Microscopy, employing Field Emission Scanning Electron Microscopy by normal mode as well as by Scanning Transmission Electron Microscopy and a High-Resolution Scanning Electron Microscopy. The results show that working with temperatures between 800 and 850°C promotes the production of GNCs, considering that their size reduces as the working temperature rises.

Graphene/Graphene Derivatives from Coal, Biomass, and Wastes: Synthesis, Energy Applications, and Perspectives

“…(Figure ). ,,,, Similar to the conventional source-derived graphene, the LCP-based graphene derivatives also show similar charge storing ability and efficiency as reported by different studies. ,,,,,− As mentioned earlier, the coal-based graphene derivatives are found to be efficient electrode materials for energy storage applications, as supported by several research studies. Zhou et al reported the use of graphitized anthracite-based graphene derivatives for their electrochemical analysis with 6 M KOH (aqueous electrolyte) in a three-electrode supercapacitor cell at room temperature.…”

“…(Figure 19). 46,84,96,100,125 Similar to the conventional sourcederived graphene, the LCP-based graphene derivatives also show similar charge storing ability and efficiency as reported by different studies. 57,72,80,84,98,126−128 As mentioned earlier, the coal-based graphene derivatives are found to be efficient electrode materials for energy storage applications, as supported by several research studies.…”

“…Coal tar pitch (CTP) is a highly aromatic material with a mixture of heterocyclic systems. Because of its structural favorability, it can be easily transformed into graphitic materials by the application of controlled thermal processes. ,, In a study, Puente-Siller et al successfully utilized CTP for the synthesis of graphene nanocapsules (GNCs) through pulverization of the CTP with nano-Zn and potassium hydroxide (KOH) in the solid state followed by their thermal treatment under N 2 flow. They found that at temperatures of 600 and 700 °C, there is difficulty in the removal of inorganic impurities, whereas the samples with the best structural characteristics were obtained at the temperatures of 800 and 850 °C with the formation of spherical particles of nanometric size.…”

Low-Grade Coal Feedstock for the Synthesis of High-Valued Graphene Derivatives for Energy Storage Application

“…13−15 Among these, the naturally available coal is seen as a promising candidate for graphene synthesis with optimal quality and yield, as reported in the literature. 18,21 Several studies have described the use of coal as a potential carbonaceous source for high-valued graphene production. 22−25 However, most of the techniques involved require high energy, high temperature, and drastic treatments with high maintenance, resulting in the high cost of the synthesized graphene derivatives, and the highgrade coals were utilized as precursors.…”

“…With the emergence of graphene applications and its continuous introduction into newer fields, there has been a huge demand for this unique functional carbon material in large scale. , Therefore, researchers are now exploring other natural carbonaceous materials for their suitability as a precursor for low cost, environment friendliness, and large-scale production of graphene and its derivatives. − Among these, the naturally available coal is seen as a promising candidate for graphene synthesis with optimal quality and yield, as reported in the literature. , Several studies have described the use of coal as a potential carbonaceous source for high-valued graphene production. − However, most of the techniques involved require high energy, high temperature, and drastic treatments with high maintenance, resulting in the high cost of the synthesized graphene derivatives, and the high-grade coals were utilized as precursors. ,, This drawback in the synthesis strategy of coal-derived graphene has motivated the researchers for the investigation of a simpler yet more effective synthetic pathway for graphene derivatives, using low-grade coal feedstock as the starting material.…”