Production of three-dimensional porous polydopamine-functionalized attapulgite/chitosan aerogel for uranium(VI) adsorption

A novel three-dimensional porous polydopamine-functionalized attapulgite/chitosan (AT@PDA/CS) aerogel was designed and prepared for uranium(VI) adsorption, and its morphology and structure were characterized by TEM, SEM-EDS, XRD, FT-IR, Raman and XPS techniques. According to batch experiments, its adsorption equilibrium was reached within 40 min at pH 5.0. The adsorption isotherms was fitted well for Langmuir isotherm model and maximum adsorption capacity was 175.1 mg g−1 at 328 K. The thermodynamic analysis indicated that the adsorption was an endothermic and spontaneous process. Furthermore, the aerogel has superior absorption reusability and the removal efficiency was maintained at 78% after five adsorption–desorption cycles.