Digital Twins solve the mystery of Raman spectra of parental and reduced graphene oxides

TL;DR

This paper uses digital twins and atomic spin-density simulations to explain the origin of the D-G doublet Raman spectra in parental and reduced graphene oxides, revealing structural reasons behind their spectral features.

Contribution

It introduces a digital twin approach with atomic spin-density algorithms to analyze and explain Raman spectral features of graphene oxides, providing new insights into their structural origins.

Findings

D-G doublets originate from sp3-sp2 C-C stretchings.

Multilayer stacking influences rGO spectral features.

Oxidation and reduction processes affect C-C bond arrangements.

Abstract

A still amazing identity of the D-G doublet Raman spectra of parental and reduced graphene oxides is considered from the digital twins viewpoint. About thirty DTs, presenting different aspects of the GO structure and properties, were virtually synthesized using atomic spin-density algorithm, which allowed reliably displaying reasons for this extraordinary spectral feature. In both cases, it was established that the D-G doublets owe their origin to the sp3-sp2 C-C stretchings, respectively. This outwardly similar community of the doublets origin of GO and rGO is thoroughly analyzed to reveal different grounds of the feature in the two cases. Multilayer packing of individual rGO molecules in stacks, in the first case, and spin-influenced prohibition of the 100% oxidative reaction, the termination of which is accompanied with a particular set of highly ordered by length sp3- and sp2 C-C bonds, protecting the carbon carcass from destruction caused by the stress induced sp2-to-sp3 transformation, in the second, are the main reasons. The DT concept has been realized on the basis of virtual vibrational spectrometer HF Spectrodyn.