Amino modified mesostructured silica nanoparticles for efficient adsorption of methylene blue

In this work, mesostructured silica nanoparticles (MSNAP) with high adsorptivity were prepared by a modification with 3-aminopropyl triethoxysilane (APTES) as a pore expander. The performance of the MSNAP was tested by the adsorption of MB in a batch system under varying pH (2–11), adsorbent dosage (0.1–0.5 g L−1), and initial MB concentration (5–60 mg L−1). The best conditions were achieved at pH 7 when using 0.1 g L−1 MSNAP and 60 mg L−1MB to give a maximum monolayer adsorption capacity of 500.1 mg g−1 at 303 K. The equilibrium data were evaluated using the Langmuir, Freundlich, Temkin, and Harkins–Jura isotherms and fit well to the Freundlich isotherm model. The adsorption kinetics was best described by the pseudo-second order model. The results indicate the potential for a new use of mesostructured materials as an effective adsorbent for MB.

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► High adsorptivity of MSNAP was prepared using 3-aminopropyl triethoxysilane.
► The maximum monolayer adsorption uptake of MB onto MSNAP was 500.1 mg g−1 at 303 K.
► The Freundlich model fit well with the equilibrium data.
► Adsorption was kinetically followed the second-order model.
► MSNAP is a competent adsorbent compared to various other mesostructured materials.