Effect of surface chemistry on the adsorption of basic dyes on carbon aerogels

This paper focuses on how the surface chemical groups of carbon aerogels (CAs) affect their adsorption properties of basic dyes. First of all, the surface structures of CAs were tailored by controlling carbonization temperatures and oxidation treatments including HNO₃ oxidation, H₂O₂ oxidation and hot air oxidation. The pore structures of samples were investigated by N₂ adsorption–desorption analysis. In addition, their surface chemistries were characterized by Boehm titration, elemental analysis and XPS analysis. Subsequently, the adsorption capacities of the typical basic dyes on them were determined by UV Spectroscopy. The results show that the surface chemistry of CAs plays a key role in dye adsorption performance. HNO₃ oxidation can produce much acidic groups on the surface of sample, such as carboxyl, lactone and phenolic groups, resulting in an increase in the adsorption amounts of basic dyes.