Voltammetric studies of the gradual thermal decomposition of activated carbon surface oxygen complexes

Effect of surface modification of an engineered activated carbon on the sorption of 2,4-dichlorophenoxy acetic acid and benazolin from water

“…The higher BET surface area of F400AN and its lower elemental oxygen content (given in Table 2) also gives further evidence of the elimination of some surface functional groups due to heat treatment. A similar phenomenon has also been observed by other researchers [6][7][8]. The appearance on the graph of a 'well' in the region between 9 and 10 Å is caused by the DFT model which cannot model values in that region and it does not suggest a decrease in pore volume [9][10][11].…”

Influence of the surface chemistry of modified activated carbon on its electrochemical behaviour in the presence of lead(II) ions

“…The surface elemental compositions (in %) as well as the range of separate peak positions (BE) and their relative peak area (rpa in %) are shown in Tables 2-4. Deconvolution of the C 1s spectra ( Table 2) These assignments agree very well with the extensive XPS studies performed on commercially available activated carbons used as catalyst supports and a number of other carbonaceous materials [27,[43][44][45][46][47]. Heat treatment under vacuum or in an ammonia-and/or oxygen-containing atmosphere raises the atomic percentage of surface carbon in relation to an unmodified sample, whereas oxidation with nitric acid decreases this quantity.…”

“…2) of an HTA carbon electrode. On the other hand, the electric double layer capacity of PACE was correlated with H 3 O + ion adsorption [47,59].…”

“…Three main peaks, corresponding to the C@O (530.6 eV), CAO (532.3 eV) and adsorbed water molecules (536.3 eV), are observed for all the samples studied. The other two peaks, with binding energies 533.5 and 534.3 eV, can be ascribed to CAOAC and C@NAO moieties, respectively, in different surface oxygen-as well as oxygen-and nitrogen-containing functional groups [45][46][47][48]. The higher relative concentration of surface carbonyl groups on ammonia-treated carbons (HTA, OPA) suggests their higher ability to chemisorb dioxygen with the formation of a superoxide species (in the first stage) and then carbonyl moieties (surface autocatalytic oxidation) according to oxygen carbon electrode action [50][51][52].…”

Reduction and oxidation of a Pd/activated carbon catalyst: evaluation of effects

“…Because the negative polarization of an electrode reduces palladium oxides to metallic Pd, the electrode material (activated carbon and dispersed metal crystallites) electrosorbs hydrogen ions more strongly in an acidic environment (a nearly fourfold increase in electric double layer capacity) but negative ions (probably hydride ions [39]) less strongly in a basic environment (2.5-fold increase).…”