Enhanced graphitic domains of unreduced graphene oxide and the interplay of hydration behaviour and catalytic activity

TL;DR

This study demonstrates that mild thermal treatment can significantly enlarge graphitic domains in graphene oxide without losing functional groups, impacting hydration behavior and catalytic activity.

Contribution

It provides direct TEM evidence of graphitic domain growth in GO during mild thermal treatment and links this to hydration and catalytic properties.

Findings

Graphitic domains increased from 40 nm² to 200 nm².

Functional groups remain intact during thermal treatment.

Enlarged domains influence hydration and catalytic performance.

Abstract

Previous studies indicate that the properties of graphene oxide (GO) can be significantly improved by enhancing its graphitic domain size through thermal diffusion and clustering of functional groups. Remarkably, this transition takes place below the decomposition temperature of the functional groups and thus allows fine-tuning of graphitic domains without compromising with the functionality of GO. By studying the transformation of GO under mild thermal treatment, we directly observe this size enhancement of graphitic domains from originally 40 nm2 to 200 nm2 through an extensive transmission electron microscopy (TEM) study. Additionally, we confirm the integrity of the functional groups during this process by comprehensive chemical analysis. A closer look into the process confirms the theoretically predicted relevance for the room temperature stability of GO. We further investigate the influence of enlarged graphitic domains on the hydration behaviour of GO and catalytic performance of single-atom catalysts supported by GO.