Role of surface chemistry in modified ACF (activated carbon fiber)-catalyzed peroxymonosulfate oxidation

• Published in: Applied surface science 2016-10, Vol.383, p.142-150
• Main Authors: Yang, Shiying, Li, Lei, Xiao, Tuo, Zheng, Di, Zhang, Yitao
• Format: Article
• Language: English
• Subjects: Activated carbon; Activated carbon fiber; Carbon fibers; Catalysis; Catalysts; Catalytic peroxymonosulfate oxidation; Heat treatment; Nitration; Nitrogen-containing functional groups; Oxidation; Surface chemistry; Surface modification; XPS spectra deconvolution
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2016.04.163

[Display omitted] •ACF can efficiently activate peroxymonosulfate to degrade organic pollutants.•Basic functional groups may mainly increase the adsorption capacity of ACF.•C1, N1, N2 have promoting effect on the ACF catalyzed PMS oxidation.•Modification by heat after nitric acid is also a way of ACF regeneration. A commercial activated carbon fiber (ACF-0) was modified by three different methods: nitration treatment (ACF-N), heat treatment (ACF-H) and heat treatment after nitration (ACF-NH), and the effects of textural and chemical properties on the ability of the metal-free ACF-catalyzed peroxymonosulfate (PMS) oxidation of Reactive Black 5 (RB5), an azo dye being difficultly adsorbed onto ACF, in aqueous solution were investigated in this work. Surface density of functional groups, surface area changes, surface morphology and the chemical state inside ACF samples were characterized by Boehm titration, N2 adsorption, scanning electron microscopy in couple with energy dispersive spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS), respectively. XPS spectra deconvolution was applied to figure out the importance of surface nitrogen-containing function groups. We found that π-π, pyridine and amine have promoting effect on the catalytic oxidation while the −NO2 has inhibitory effect on the ACF/PMS systems for RB5 destroy. Sustainability and renewability of the typical ACF-NH for catalytic oxidation of RB5 were also discussed in detail. Information about our conclusions are useful to control and improve the performance of ACF-catalyzed PMS oxidation for organic pollutants in wastewater treatment.