Mesoporous Silica Nanoparticles for the Uptake of Toxic Antimony from Aqueous Matrices

Contamination of water sources by toxic antimony Sb(III)ions posesa threat to clean water supplies. In this regard, we have prepareda mesoporous silica nanoparticle (MSN)-derived adsorbent by reversemicroemulsion polymerization, using cetyltrimethylammonium chloride(CTAC) and triethanolamine (TEA) as co-templates. The physical andchemical properties were characterized using advanced tools. The MSNexhibits a higher surface area of up to 713.72 m(2)& BULL;g(-1), a pore volume of 1.02 cm(3)& BULL;g(-1), and a well-ordered mesoporous nanostructure withan average pore size of 4.02 nm. The MSN has a high adsorption capacityfor toxic Sb(III) of 27.96 mg & BULL;g(-1) at pH 6.0and 298 K. The adsorption data followed the Langmuir isotherm, whilethe kinetics of adsorption followed the pseudo-second-order model.Interestingly, the effect of coexisting iron showed a promoting effecton Sb(III) uptake, while the presence of manganese slightly inhibitedthe adsorption process. The recyclability of the MSN adsorbent wasachieved using a 0.5 M HCl eluent and reused consecutively for threecycles with a more than 50% removal efficiency. Moreover, the characterizationdata and batch adsorption study indicated physical adsorption of Sb(III)by mesopores and chemical adsorption due to silicon hydroxyl groups.