Constructing hydrangea-like hierarchical zinc-zirconium oxide microspheres for accelerating fluoride elimination

The design and synthesis of scientific and rational adsorbents is an effective method for improving adsorption properties. Herein, innovative 3D hydrangea-like hierarchical porous zinc-zirconium oxide microspheres (HPZZ) were synthesized through a simple hydrothermal reaction and calcination process for enhanced fluoride adsorption in aqueous solutions. Benefiting from its distinctive structural and component advantages, the newly designed adsorbent delivered superior adsorption performance (107.41 mg/g), which outperformed most reported metal oxide-based adsorbents. The adsorption kinetics and isotherm data were precisely fitted by pseudo-second-order and Langmuir models. Furthermore, coexisting anions had insignificant effects on the HPZZ. More importantly, the adsorption mechanism between the HPZZ and fluoride could be attributed to electrostatic interactions, complexation, and ion exchange. Interestingly, the exhausted adsorbent could be regenerated for four cycles. A practical application test verified that the HPZZ was a rapid and effective adsorbent for groundwater purification. Therefore, this work brings a novel active material for fluoride decontamination, with the current work providing great significance in environmental research.