Oxidation and stability of multi-walled carbon nanotubes in hydrogen peroxide solution
Artikel i vetenskaplig tidskrift, 2018

The oxidation and stability of multi-walled carbon nanotubes (CNTs) have been investigated by exposing CNTs in 30% w/v H2O2 solution at room temperature (RT) for up to 8 weeks and at 80 degrees C for up to 8 h. H2O2 oxidation not only generated surface oxygen-containing groups, but also created surface defects, as disclosed by results of temperature-programmed desorption and X-ray Photoelectron Spectroscopy. The total surface oxygen content was found to be correlated to the final H2O2 concentration. The higher the total surface oxygen content on CNTs, the lower the final H2O2 concentration. Meanwhile, the carbon oxidation and simultaneous H2O2 decomposition were observed and confirmed by an online analysis of evolved gases during the oxidation stepwise heated from room temperature to 80 degrees C. Raman study showed that the DIG and D'/G ratios of the CNTs oxidized at RT first decreased with an oxidation time of 4 weeks and then increased when prolonging the oxidation time up to 8 weeks. Similar trend was also observed on the CNTs oxidized at 80 degrees C. The size of CNTs was gradually reduced with increasing oxidation time as shown by SEM studies. Our work reveals the critical changes in the surface oxygen groups as well as the changes in morphology at two distinct stages of hydrogen peroxide treatment, purification and then functionalization. CNTs can withstand 30% w/v H2O2 oxidation for only a certain time, while they may be damaged or consumed eventually in long-term applications. Our study contributes to filling in the knowledge gap about CNT surface oxidation and structural changes with H2O2 treatment under industrial conditions.

Functionalization

Purification

Oxidation

H2O2

Carbon nanotubes

Författare

Isaac Adjei Safo

Ruhr-Universität Bochum

Carl von Ossietzky Universität Oldenburg

Fang Liu

Chalmers, Industri- och materialvetenskap, Material och tillverkning

Kunpeng Xie

Chalmers, Kemi och kemiteknik, Kemiteknik, Kemisk reaktionsteknik

Wei Xia

Ruhr-Universität Bochum

Materials Chemistry and Physics

0254-0584 (ISSN)

Vol. 214 472-481

Ämneskategorier

Oorganisk kemi

Materialkemi

Annan kemi

DOI

10.1016/j.matchemphys.2018.05.001

Mer information

Senast uppdaterat

2018-08-22