Facile preparation of MgO-loaded SiO2 nanocomposites for tetracycline removal from aqueous solution

The MgO-loaded SiO 2 nanocomposites were successfully synthesized via a facile precipitation and calcination method, and used for the elimination of antibiotics from aqueous solution. Multiple techniques such as X-ray photoelectron spectroscopy (XPS), fourier transform infrared (FT-IR), transmission electron microscope (TEM), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) were employed to characterize the structure and morphology of the obtained nanocomposites. The effects of the loading content of MgO , initial solution pH and temperature on the adsorption performance of MgO-loaded SiO 2 nanocomposites were assessed by removing tetracycline from aqueous solution. It was found that 50% MgO-loaded SiO 2 exhibited excellent adsorption performance towards tetracycline with a removal rate above 80% in a wide pH range of 4–10, which was much higher than that of individual MgO and mesoporous SiO 2 . The nanocomposite possessed higher specific surface area (356.02 m 2  g −1 ) and smaller MgO particles compared with pure MgO (81.02 m 2  g −1 ), which can provide more active sites, thus enhancing the adsorption performance towards tetracycline. The electrostatic interaction and inner-sphere complexation between nanocomposites and tetracycline molecules were considered to play important roles in the adsorption process of tetracycline. The as-synthesized nanocomposites as promising adsorbents have a potential application in the removal of antibiotics from aqueous solution.