The low density CeO₂, Pr₂O₃ and Nd₂O₃ aerogels were synthesized by a novel solution-freeze-drying-calcination route. The bulk densities of the CeO₂, Pr₂O₃ and Nd₂O₃ aerogels were calculated to be 8.10, 10.67 and 9.80 mg/cm³, respectively. Moreover, the structure of metal oxide aerogels was similar due to the same template materials, which made them possible to be appealing materials for adsorption. The maximum adsorption capacity for U(VI) of the CeO₂, Pr₂O₃ and Nd₂O₃ aerogels reached 481.5, 840.6 and 587.3 mg/g (pH = 7, T = 25 °C), respectively, which were much higher than most of other modified metal oxides. Moreover, at low concentration of U(VI) (5 mg/L), it was completely dislodged by CeO₂ aerogel and the remaining U(VI) was below 0.006 mg/L, which was lower than the effluent standards of United States Environmental Protection Agency and World Health Organization. Besides, after five cycles, the adsorption efficiency of metal oxide aerogels almost remained at a high level. Due to the excellent adsorption performance and high reusability, the three metal oxide aerogels would be promising adsorbents for the removal of U(VI).

通过新颖的溶液-冷冻-干燥-煅烧路线合成了低密度的CeO ₂，Pr ₂ O ₃和Nd ₂ O ₃气凝胶。CeO ₂，Pr ₂ O ₃和Nd ₂ O ₃气凝胶的堆积密度经计算分别为8.10、10.67和9.80 mg / cm ³。此外，由于相同的模板材料，金属氧化物气凝胶的结构相似，这使其成为有吸引力的吸附材料。CeO ₂，Pr ₂ O ₃和Nd ₂对U（VI）的最大吸附容量O ₃气凝胶分别达到481.5、840.6和587.3 mg / g（pH = 7，T = 25°C），远高于大多数其他改性金属氧化物。而且，在低浓度的U（VI）（5 mg / L）下，它被CeO ₂气凝胶完全清除，其余的U（VI）低于0.006 mg / L，低于美国环境署的出水标准。保护局和世界卫生组织。此外，经过五个循环后，金属氧化物气凝胶的吸附效率几乎保持在较高水平。由于出色的吸附性能和高可重复使用性，三种金属氧化物气凝胶将成为去除U（VI）的有前途的吸附剂。