PAMPS--NiSiO(OH) multiwalled nanotubes as a novel nano-sorbent for the effective removal of Pb() ions

The existence of Pb( ii ) ions in water systems poses significant potential hazards to public health and the environment. In the present study, poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) brush-modified Ni 3 Si 2 O 5 (OH) 4 nanotubes were prepared, and their adsorption efficiency against the Pb( ii ) ions was investigated. The characterization results of FTIR spectroscopy, TGA, TEM, and XPS indicated the successful grafting of PAMPS on the surface of free Ni 3 Si 2 O 5 (OH) 4 NTs, and the prepared PAMPS- g -Ni 3 Si 2 O 5 (OH) 4 NTs exhibited a 6-8 nm grafting layer, which could provide abundant binding sites for metal adsorption. During the Pb( ii ) removal process, a pH-dependent adsorption behavior was observed, and the adsorption processes fitted well with the pseudo-second-order kinetic model and the Langmuir isotherm model. Compared with unmodified Ni 3 Si 2 O 5 (OH) 4 , the PAMPS- g -Ni 3 Si 2 O 5 (OH) 4 NTs exhibited obviously faster adsorption of Pb( ii ) and higher equilibrium adsorption capacity for the removal of Pb( ii ). The maximum adsorption capacity calculated via the Langmuir isotherm model was 0.653 mmol g −1 (135.3 mg g −1 ) at 298 K. In a metal coexisting system, the total adsorption capacity of the NTs was increased; this indicated the potential of the proposed NTs in the removal of Pb( ii ) from metal coexisting wastewater. This study showed the significant potential of PAMPS- g -Ni 3 Si 2 O 5 (OH) 4 NTs in the effective removal of Pb( ii ). PAMPS- g -Ni 3 Si 2 O 5 (OH) 4 NTs for the effective removal of Pb( ii ).