Efficient removal of Th(IV) from aqueous solution by reusable porous Al2O3-SiO2 composites

In this study, porous Al2O3-SiO2 composite materials were successfully constructed and applied to remove Th(IV) in aqueous solution. There was a large amount of OH− on the surface of Al2O3-SiO2 composite materials in aqueous solution, which would effectively capture positively charged Th(IV) to form a complex. The maximum adsorption capacity reached 361.60 mg g−1 and the adsorption percentage was as high as 99.9% in low initial concentration of Th(IV) solution. In addition, it was worth noting that the adsorption efficiency could maintain more than 90% even after 5 cycles. In view of these results, porous Al2O3-SiO2 composite materials should be considered to be an efficient and reusable adsorbent for Th(IV).