Preparation of monodispersed mesoporous silica particles and their applications in adsorption of Au3+ and Hg2+ after mercapto-functionalized treatment

•Mesoporous silica particles were first synthesized by using THEEDA as catalyst.•The particles with the size about 30 nm present stable colloidal suspensions.•Thiol functional groups were modified into the silica particles.•Examined the influence of adjusting TEOS/MPTMS on the structure and morphology.•The modification particles could effectively remove heavy metal ions Au3+ and Hg2+.

Colloidal suspensions of monodispersed nanoporous silica particles were first successfully synthesized by using small organic amine (N,N,N′,N′-Tetrakis(2-hydroxyethyl)ethylenediamine) as basic catalyst; and then, the mercaptopropyl functionalized counterpart was also fabricated by co-condensation of mercaptopropyl silane and tetraethyl orthosilicate in a similar way. These nanoporous silica particles were characterized by field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), nitrogen adsorption-desorption and X-ray diffraction. Experimental results indicated that all the spherical nanoporus silica particles are uniform (with the size of about 30–40 nm) and possessed large specific surface area (about 500 m2/g), large pore volume (>1.6 cm3g−1) and narrow pore sizes distribution (<3 nm). Furthermore, the mercaptopropyl functionalized products served as adsorbent to efficiently remove Hg2+ and Au3+ ions in water.

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