Bottom-up synthesis of MOF-derived magnetic Fe-Ce bimetal oxide with ultrahigh phosphate adsorption performance

• Bottom-up method is used for the synthesis of phosphate adsorbents. • Fe-doping increased Ce (III) proportion and generated magnetism. • The maximum absorption capacity is up to 357 mg g −1 by Langmuir model. • The synergistic effects effectively enhanced the utilization of Ce element. The intrinsic properties of metal-based adsorbents originate from multiples factors such as surface functional groups, electronic and dimensional structures. However, the synthetic strategies are limited to top-down methods, which inhibited the improvement of adsorbent performance. Herein, Fe-Ce bimetal oxide composites are prepared by a bottom-up modified MOF template method. MOF template-directed nano rod-like morphology can expose more active sites and facilitate phosphate access to active sites. The introduction of citric acid effectively increased the amount of surface –OH groups and greatly improved the phosphate adsorption capacity. Furthermore, the Fe dopant enables the high Ce(III) fraction and generate magnetic property for Fe-Ce bimetal oxide composites, which are capable of enhancing the intrinsic phosphate adsorption performance. The results show that the optimized Fe-Ce bimetal adsorbent showed remarkably high phosphate adsorption capacity, achieving a maximum phosphate adsorption capacity of 357 mg g −1 by Langmuir model. High adsorption capacity and high magnetic separation efficiency characteristics make this adsorbent a promising material for phosphate treatment. The above results further prove the effectiveness of the bottom-up strategy in the design process of environmental functional materials.