Effects of nitrogen plasma treatment on the surface characteristics of olive stone-based activated carbon

ABSTRACT

Nitrogen plasma treatment (NPT) of activated carbon (AC) at different conditions was carried out to introduce nitrogen-containing groups onto olive stone-activated carbon (OSAC) surfaces. Textural characteristics of raw and irradiated samples were analyzed by N₂ and CO₂ adsorption. Surface chemical functional groups were analyzed by X-ray photoelectron spectrometry (XPS) and Fourier Transformed Infrared spectroscopy. The results showed that after NPT, the surface textural properties of irradiated OSAC were slightly damaged, and a gradual decrease in surface area and pore volume was observed during the irradiation. XPS revealed that NPT could change the distribution of oxygen functional groups on the OSAC surface and there were more nitrogen atoms incorporated into the aromatic ring. A tentative explanation for the modification process is proposed. Phenol adsorption was enhanced from 110 mg/g for untreated AC to 635 mg/g for 30-min plasma-treated OSAC.

KEYWORDS:

• Activated carbon
• plasma treatment
• surface characteristics
• phenol adsorption

Acknowledgements

The authors extend their gratitude to Professor Dr. Fco Javier Lopez Garzon from Granada University of Spain for his valuable advices and his assistance in the textural analysis of AC samples which are BET-specific surface area, XPS and FT-IR analysis.

Disclosure statement

No potential conflict of interest was reported by the authors.