Synthesis of amine functionalization carbon nanotube-low symmetry porphyrin derivatives conjugates toward dye and metal ions removal

Carbon nanotubes were successfully functionalized with amine groups and conjugated with two low-symmetry prophyrine derivatives to increase their active sites. Batch adsorption tests were performed to examine the applicability of the prepared materials for the adsorption of methylene blue (MB) from waters. Compound 3 displayed better adsorption efficiency compared with other compounds at different values of pH. High MB adsorption efficiency (≈100%) was attained by compound 3 when the dosage of adsorbent increased from 0.001 to 0.06 g. The kinetics modeling studies demonstrated the adsorption followed the pseudo-second-order model. The experimental data were best fitted to Freundlich isotherm model suggesting multilayer adsorption of MB over the surface of the prepared adsorbent. The study showed that the adsorption of MB was a complex mechanism involving non-electrostatic and electrostatic interactions. The reported results showed that the prepared material to be an effective adsorbent for simultaneous adsorption of MB and toxic metal ions from industrial wastewaters.