Synthesis of graphene from activated carbon at liquid nitrogen temperature and its detailed structural analysis

The present study deals with the synthesis of graphene using thermal quenching of pre-heated activated carbon (a-C) (1370 K for 3 h) at liquid nitrogen temperature and its detailed structural analysis using XRD, TEM, FTIR and Raman spectroscopy. The analysis of lattice parameters (L-a, L-c,L- and d) of constituent nanographitic domains using XRD shows restoration of graphene-like structure in the resultant product (a-CL). TEM image reveals porosity and partially crystallinity (from SAED) in a-C. While thin layers of graphene are observed in the TEM images of a-CL Deconvoluted Raman spectra have been used to investigate the evolution of crystalline behaviour of a-C with temperature in view of Ferrari and Robertson's three-stage model. The evolution of G peak and increase in I-D/I-G reveals restoration of crystallinity in a-CL. The development of the D peak indicates disordering of graphite but ordering of amorphous carbon. The reported method is technologically beneficial for graphene synthesis for large number of applications such as supercapacitors, H-2 storage, gas separation and purification.

Automated summary

This study focuses on the synthesis of graphene through thermal quenching of pre-heated activated carbon at liquid nitrogen temperature, and detailed structural analysis using XRD, TEM, FTIR, and Raman spectroscopy. The analysis revealed the restoration of graphene-like structure with porosity and partial crystallinity in the resulting product, as well as the evolution of crystalline behavior with temperature. The method shows technological benefits for graphene synthesis in various applications.