A simple technique for the facile synthesis of novel crystalline mesoporous ZrO2-Al2O3 hierarchical nanostructures with high lead (II) ion absorption ability

In this study, a simple evaporation-induced self-assembly process for the facile synthesis of crystalline ZrO2-Al2O3 hierarchical nanostructures was reported. The synthesized hierarchical nanostructures display a long ranged ordered mesoporous structure, and demonstrated excellent adsorption properties for Pb (II) ions removal due to its larger surface-to-volume ratio. Characterization by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller (BET) analysis reveal that the as-synthesized nanostructures possess large BET surface area (278 m2 g−1), relatively large pore size (12.99 nm) and high pore volume (0.925 cm3 g−1). The Pb (II) ions adsorption processes conformed to the pseudo-second order kinetics and the Langmuir adsorption isotherm was suitable in describing the lead removal processes where the equilibrium time for the Pb (II) ions adsorption on the ZrO2-Al2O3 nanostructures was 30 min. These crystalline mesoporous ZrO2-Al2O3 hierarchical nanostructures possess a maximum adsorption capacity of 110.49 mg g−1 for Pb (II) and hence are an attractive adsorbent for the removal of heavy metal ion from water. In addition, our synthesized ZrO2-Al2O3 hierarchical nanostructures also display good reusability properties.