Oxygen Functionalized and Pristine Carbon Nanotubes Efficiency for Adsorption of Methyl Orange Dye

Pristine and oxygen functionalized multi-walled carbon nanotubes were used as adsorbent for removal of Methyl Orange (MO) dye. The adsorption was carried out under different pH values. The analysis of results indicated that the adsorption characteristics of the MO dye by pristine carbon nanotubes (P-CNTs) and oxygen functionalized carbon nanotubes (O2-CNTs) are highly influenced by the pH of the medium. The study report that the best pH medium of solution for the adsorption of MO on both CNTs was acid medium. The point of zero charge (pzc) of O2-CNTs and P-CNTs were determined as function of pH. The pzc of P-CNTs and O2-CNTs are found to be 4.7 and 3.9, respectively. The adsorption data have been analyzed using Langmuir and Freundlich. Fitting the equilibrium adsorption data by Langmuir and Freundlich models shows that experimental data well explained by the Langmuir equation.