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.