Electron Spin Echo Studies of Hydrothermally Reduced Graphene Oxide

Maria A Augustyniak-Jabłokow,Ryhor Fedaruk,Raanan Carmieli,Krzysztof Tadyszak,Roman Strzelczyk

doi:10.1021/acs.jpcc.0c11316

Abstract

Ecofriendly hydrothermal reduction of graphene oxide is widely used for producing hydrogels and aerogels, but it yields partly reduced graphene oxide (prGO) containing oxygen groups and some number...

Highlights

The reduction of graphene oxide (GO)[1] allows the production of the chemically derived form of graphene known as reduced graphene oxide.[2]
The continuous wave (CW) electron paramagnetic resonance (EPR) spectrum of partly reduced GO (prGO) is dominated by two Lorentzian lines of conduction electrons and paramagnetic centers exchange-coupled via RKKY (Ruderman−Kittel− Kasuya−Yosida) interactions.[34]
We have studied the properties of paramagnetic centers (PCs) in prGO using electron spin echo spectroscopy

Summary

■ INTRODUCTION

The reduction of graphene oxide (GO)[1] allows the production of the chemically derived form of graphene known as reduced graphene oxide (rGO).[2]. Hydro- and aerogels of the hydrothermally reduced GO, referred to here as partly reduced GO (prGO), can be used as supercapacitor electrodes[4] and a base for hybrid materials with a broad application range.[5−7] according to X-ray photoelectron spectroscopy (XPS) and electron dispersive spectroscopy (EDS) of prGO materials,[8,9] only 30% of functional groups are removed by hydrothermal reduction Such reduction results in significant carbon loss.[10] Created defects introduce disorder into the graphene structure.[11] Phenomena characteristic of the pure graphene are modified, and new properties can appear.[2] Understanding processes responsible for modifying the properties of graphene is important for further developments of its production technology. Fourier transform infrared spectra were obtained with a JASCO Spectrometer FT/IR-4700 in the spectral range 400− 4000 cm−1 with 1 cm−1 resolution at 21 °C

■ RESULTS AND DISCUSSION

■ CONCLUSIONS

■ REFERENCES