Carbon materials (namely activated carbon) are well known “universal” adsorbents and present unique advantages due to their low cost, high adsorption capacity and easy disposal [17,18]. The
performance of these materials depends greatly on their texture and surface chemistry [18,19]. The presence of oxygen atoms on their surface originates a variety of functional groups that can
interact with the adsorbents [18–21]. The effect of surface oxygen groups on the adsorption of organic compounds has been studied on oxidised activated carbons [17,22,23], carbon xerogels [24] and carbon nanotubes [25–27]. In general, it has been found that increasing the presence of oxygenated groups (i.e., more acidic samples), has detrimental effects on adsorption.