Detailed thermal reduction analyses of Graphene Oxide via in-situ TEM/EELS studies

TL;DR

This study provides a detailed in-situ TEM/EELS analysis of graphene oxide's thermal reduction, revealing the transformation of oxygen groups, water desorption, and graphitization across a wide temperature range, informing its thermal behavior and applications.

Contribution

It introduces a comprehensive in-situ TEM/EELS methodology to analyze the thermal reduction process of graphene oxide in detail.

Findings

Identification of oxygen functional group transformations

Water desorption mechanisms at different temperatures

Graphitization process observed up to 1200°C

Abstract

We report an in-depth study of the reduction of graphene oxide (GO) by in-situ thermal transmission electron microscopy (TEM) analysis. In-situ heating high-resolution TEM (HRTEM) imaging and electron energy-loss spectroscopy (EELS) measurements have been combined to identify the transformations of different oxygen functional groups, the desorption of physisorbed and chemisorbed water and the graphitization as a function of the temperature in the range from 70 up to 1200{\deg}C. A model for the general removal of water and OFGs is proposed based on different chemical and physical parameters that have been monitored. All this unique information provides a detailed roadmap of the thermal behaviour of GO at an extended range of temperature. This is not only of interest to understand the thermal reduction process of GO but also of critical relevance to the response of GO in applications when exposed to thermal effects.