Adsorption Studies of Benzoic Acid on Single Walled Carbon Nanotubes

Carbon based nanostructures, specifically carbon nanotubes due to their unique surface adsorption properties can become the choice materials for removal of toxic chemicals from water. In this study, we will present our investigations on adsorption of benzoic acid on single walled carbon nanotubes (SWNT) synthesized by direct thermal decomposition of ferrocene (Fe(C₅H₅)₂). The analysis of the adsorption isotherms of benzoic acid and its conjugate base on these carbon nanotubes indicate that the adsorption capacity of both benzoic acid and benzoate on them are significantly higher than those reported previously on other carbon based adsorbents. We also find that these SWNTs provide better adsorption capacity than commercially available multiwalled carbon nanotubes (MWNT) with different functionalization. We attributed this to the smaller nanotube sizes (diameters) of SWNT which gives rise to stronger surface potentials. A detailed discussion of these experimental results along with analysis and comparison of results obtained from Molecular Dynamics (MD) simulation on similar system will be presented.