Synthesis of catechol-polyethyleneimine nano/submicro-particles via mussel-inspired chemistry for highly efficient removal of methyl orange

Herein, a novel catechol-polyethyleneimine (CCh-PEI) nano/submicro-particles (CP-NPs) was synthesized via a facile mussel-inspired co-precipitation method for highly efficient methyl orange (MO) removal. The as-synthesized CP-NPs were characterized by FT-IR, SEM, TEM , EDS , XRD , TGA , Zeta potential , and BET. The adsorption properties result indicated that the optimum adsorption capacity of CP-NPs was obtained at a CCh/PEI mass ratio of 5:1. Kinetic and adsorption isotherm studies showed that the adsorption process of CP-NPs followed the pseudo-second-order model and the Langmuir isotherm model, respectively. The theoretical maximum monolayer adsorption capacity was 1392.68 mg g −1 at 303 K, which was higher than most previously reported adsorbents. Meanwhile, the adsorption was a spontaneous and exothermic process according to thermodynamic studies. In addition, the CP-NPs exhibited excellent adsorption capacity even after eight times regeneration. Thus, it suggests that CP-NPs is expected to be an economical and efficient adsorbent for MO removal.