Multi-walled Carbon Nanotube-CO-NH(CH2)2NH-SO3H: A New Adsorbent for Removal of Methylene Blue from Aqueous Media

In this study, multi-walled carbon nanotube-CO-NH(CH2)2NH-SO3H was prepared through a three-step functionalization of commercial multi-walled carbon nanotubes and then characterized using Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). In addition, the adsorption of methylene blue was investigated by using these nanotubes. In order to remove dye, the effects of different parameters including stirring time, pH value, initial concentration of dye, and amount of carbon nanotubes were studied. More than 99.5% of dye was removed at neutral pH within a short time. Pseudo-second-order equation was predicted by adsorption kinetic. Different isotherms were studied to define adsorption mechanism, and Langmuir model showed the best results compared to the other isotherms. This project offers a facile and efficient adsorption method for removing methylene blue from aqueous solution. Short stirring time, neutral pH and high qmax (the maximum adsorption capacity in saturated single layer) are the significant characteristics of this research