Self-assembly synthesis of hollow double silica @ mesoporous magnesium silicate magnetic hierarchical nanotubes with excellent performance for fast removal of cationic dyes

In this work, novel hollow double silica @ mesoporous magnesium silicate magnetic hierarchical nano tubes (MgSNTs) were successfully synthesized by using magnetic mesoporous silica nanocapsules (MSNCs) as morphology templates via a hydrothermal method for the first time. MgSNTs were characterized by transmission electron microscopy, Mapping, X-ray diffraction, Fourier transform infraed spetroscopy, N-2 adorption-desorption, X-ray photoelectron spectroscopy and vibrating sample magnetometry. The synthesized MgSNTs with high specific surface area (588 m(2)/g), average pore width (7.13 nm) and pore volume (1.05 cm(3)/g) had high removal efficiency for low concentration methylene blue (70 mg/L, 299 mg/g) and high adsorption capacities for high concentration rodamine B (300 mg/L, 752 mg/g). Besides, it could be easily recovered due with the help of gamma-Fe2O3 in the inner chamber. Moreover, the adsorption capacity, the influence of pH, adsorption kinetics and adsorption mechanism were also carefully and comprehensively investigated. The results indicated that magnetic magnesium silicate nanotubes (MgSNTs) using mesoporous silica nanocapsules as the assisted templates were promsing adsorbents for water purification. (C) 2016 Elsevier B.V. All rights reserved.