Mesoporous MnO2/SBA-15 as a synergetic adsorbent for enhanced uranium adsorption

Mesoporous MnO2/SBA-15 composites were preparedviaa simple route using KMnO(4)and MnCl(2)as Mn sources for the first time and were explored as a synergetic adsorbent for the removal of U(vi). The results demonstrated that the U(vi) adsorption capacity of both pristine SBA-15 and MnO(2)can be greatly enhanced by combining them. MnO2/SBA-15 composites exhibited remarkable U(vi) adsorption capacity. The 40%MnO2/SBA-15 sample with optimum MnO(2)content exhibited a maximum U(vi) adsorption capacity of 465.1 mg g(-1), which is much higher than those of pristine SBA-15, MnO(2)and many other adsorbents. The U(vi) adsorption process was well fitted by the Langmuir model and the pseudo-second order model. The thermodynamic data analyses revealed that the U(vi) adsorption process was spontaneous and endothermic. It was proposed that the synergetic effect played an important role in the U(vi) adsorption process. These results demonstrated that the MnO2/SBA-15 composites can be employed as a promising U(vi) adsorbent.