Abstract
Hydrothermal carbon has received increasing attention because of its simple and mild synthesis conditions. In this paper, amidoxime-functionalized hollow carbon spheres (C-HCN-AO) were synthesized via amidation cyano-rich hydrothermal carbon (C-HCN) treatment with hydroxylamine hydrochloride. NaOH solution was used to etch SiO2 to achieve hollow structure. The maximum sorption capacity of hollow C-HCN-AO sphere toward U(VI) was 355.6 mg/g at pH 5.0 and 298 K. The sorption of U(VI) by hollow C-HCN-AO sphere was predominantly controlled by inner-sphere complexation from the study of the sorption mechanism. The regeneration study displayed good reusability of hollow C-HCN-AO sphere. This work can give a guide for the design and fabrication of hollow structures in the application of pollution treatments.