The synthesis of urchin-like γ-Al2O3 hierarchical microspheres from Al foils and its rapid adsorption ability towards Congo red

Abstract

In this paper, we present a convenient hydrothermal method to synthesize hierarchical microspheres consisting of ammonium aluminum carbonate hydroxide (AACH) nanowires with a diameter of about 400 nm and length ∼50 μ m on aluminum foils. After calcination at 900 °C, hierarchical γ -Al _2 O _3 microspheres with mesoporous structures were obtained successfully, which possess a high specific surface area of 124 m ^2 g ^−1 and high porosity of 0.71cm ^3 g ^−1 . The possible formation mechanism was discussed. The as-prepared mesoporous γ -Al _2 O _3 hierarchical nanostructures exhibited improved adsorption performance towards Congo red in aqueous solution, 90% CR could be removed rapidly in 20 min, and its saturation adsorption capacity in 80 mg l ^−1 Congo red can reach to 180 mg g ^−1 , it suggests that the hierarchical γ -Al _2 O _3 microspheres with unique microstructure have potential in wastewater treatment.

Keywords

• γ-Al2O3
• NH4Al(OH)2CO3
• hierarchical nanostructures
• adsorption
• congo red