Liquid phase oxidation kinetics of an ex-cellulose activated carbon cloth by NaOCl

Abstract

The oxidation kinetics at ambient temperature of an ex-cellulose activated carbon cloth has been investigated using an aqueous solution of NaOCl. Oxidized samples were weighed and characterized by TG–TPD–MS and XPS. Weight analysis revealed three stages during the course of oxidation. The first is dominated by the creation of oxygen groups at the carbon surface with an initial oxygen uptake rate assessed at 20mgg−1min−1. The second involves a transfer of oxygenated carbonaceous matter to the liquid phase. The third corresponds to the degradation of the carbon fabric. The diameter of the fibers does not change during the first stage and decreases during the last two stages. The amount of oxygen groups fixed per gram of sample increases with oxidation time during the first two stages, and decreases during the third stage. The creation of oxygen groups progresses from the surface to the bulk. The oxidation degree of carbon atoms (CI–CIII) increases during oxidation. TPD spectra, including for water, have been examined in light of the recent literature and of the temperature-programmed surface reaction theory. The degradation of fibers is interpreted by the aromatic ring cleavage accompanying the creation of carboxylic groups.