Synthesis of hierarchical porous flower-like ZnO-AlOOH structures and their applications in adsorption of Congo Red

摘要

Graphical abstractDisplay OmittedHighlights?3D hierarchical flower-like ZnO-AlOOH composite was synthesized via a facile hydrothermal method.?ZnO-AlOOH composite exhibits higher adsorptivity for CR than pure ZnO and AlOOH.?The adsorption experiments occur in pseudo-second-order model and Langmuir model.AbstractZnO–AlOOH nanoflakes assembled in flower-like structures were produced through a simple hydrothermal route. The flower-like ZnO–AlOOH composites were used as adsorbents to remove Congo Red (CR) dye from aqueous solution and compared with pure AlOOH and ZnO adsorbents. The adsorption kinetics of the dye on the synthesised samples was described by a pseudo-second-order model. The equilibrium adsorption data of CR on the ZnO–AlOOH samples fitted well with the Langmuir model. The ZnO–AlOOH samples possessed excellent adsorption capacity (524mg/g), which was higher than those of pure AlOOH and ZnO samples. The superior CR removal efficiency of the ZnO-AlOOH samples could be attributed to their hierarchical porous structures and high specific surface areas, which are conducive to the diffusion and adsorption of the CR molecules.]]>