Electrospinning preparation and adsorption properties of mesoporous alumina fibers

Abstract

Mesoporous alumina fibers were successfully synthesized via an electrospinning technique combined with a sol–gel method in the presence of a triblock copolymer as a structure directing agent. The amorphous alumina fibers derived from the electrospun xerogel fibers after calcinations at 450 °C and the γ-Al₂O₃ fibers obtained after the xerogel fibers were calcined at 700 °C exhibit uniform mesopores with fiber diameters of 130–200 nm, and BET surface areas up to 264.1 m² g⁻¹ and 242.6 m² g⁻¹, respectively. After the xerogel fibers were calcined at 1100 °C, with the transformation from γ-Al₂O₃ to α-Al₂O₃, a significant grain growth occurs and the mesopores disappear. Further investigation indicates that the γ-Al₂O₃ fibers have good adsorption properties toward Congo red with a maximum adsorption capacity of 781.25 mg g⁻¹ for the sample obtained at 700 °C. In addition, the fibers show a good stability in acidic conditions and during a reuse process, which indicates their potential applications in adsorption as well as related areas, such as catalysis and catalyst supports.