Synthesis of novel ZnAl2O4/Al2O3 nanocomposite by sol-gel method and its application as adsorbent

In this research, ZnAl2O4/Al2O3 nanocomposites with different ZnAl2O4 (30, 50, and 70 wt.%) were successfully prepared in one step by sol-gel method and utilized for the removal of methylene blue (MB). The structural properties of nanocomposites were investigated by X-ray diffraction (XRD), differential thermal analysis (DTA), FTIR analysis, Zeta potential, and BET. The obtained results showed the synthesized nanocomposites by sol-gel method were amorphous and heat treatment at 700 degrees C led to the crystallization of zinc aluminate spinel. The maximum MB removal (70%) was obtained under o9 ptimal conditions such as initial concentration of MB (10 mg/L), pH of solution (8.5), the amount of adsorbent (0.05 g), type of adsorbent (70 wt.% ZnAl2O4/Al2O3 nanocomposite). The average size of zinc aluminate crystals in the maximum amount of zinc aluminate in the composite (70 wt.%) was calculated to be 27 +/- 1 nm and its morphology changed from sheet to mass. The specific surface area of the nanocomposite was calculated to be 70 m(2)/g. The kinetics of adsorption was fitted with the pseudo-second order model.

Automated summary

ZnAl2O4/Al2O3 nanocomposites with different ZnAl2O4 contents were successfully prepared by sol-gel method for methylene blue removal. Heat treatment led to the crystallization of zinc aluminate spinel. The maximum MB removal rate of 70% was achieved under optimal conditions.