Activated carbon aging processes characterization by Raman spectroscopy

Activated carbon is typically being used as an adsorbent material for various hazardous materials. It is common to impregnate the carbon with metal oxides in order to improve its adsorbing capabilities to polar hydrophilic compounds. Exposure of activated carbon to humidity causes water adsorption that leads to aging of the carbon. The aging process reduces the chemisorption capacity of the activated carbon, thus deteriorating its adsorption properties. In this research, the effect of aging on activated carbon was studied by non-destructive Raman spectroscopy, which enables chemical characterization of packed AC samples. Accelerated aging was achieved by controlling thermal oxidation of carbonaceous materials. The aging process of the activated carbon which includes carbon oxidation, as well as metal ions migrations was studied using Raman spectroscopy utilizing mainly D and G Raman band shifts, as well as energy dispersive spectroscopy.