Microwave-Assisted Hydrothermal Synthesis of Nanosized α-Fe₂O₃ for Catalysts and Adsorbents

Abstract

Nanosized α-Fe 2 O 3 powder was synthesized by a microwave-assisted hydrothermal reaction of Fe(NO 3 ) 3 and urea at 120 °C for 30 min. The products were characterized by X-ray diffraction, transmission electron microscopy, BET measurements, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The catalytic performance of α-Fe 2 O 3 was studied for the oxidation of CO and 2-propanol to CO 2, and the adsorption properties were investigated for the removal of As(III) in water treatment. Uniform α-Fe 2 O 3 particles about 5.0 nm in diameter were formed with a surface area of around 173.0 m 2 g –1 . When 0.1 g of α-Fe 2 O 3 powder worked as a catalyst, CO was oxidized to CO 2 over 120 °C and completely transformed to CO 2 at 170 °C, and 2-propanol was fully oxidized to CO 2 at 350 °C. The adsorption capacity for As(III) reached 51.8 mg g –1 at room temperature. This work facilitates the preparation of nanosized α-Fe 2 O 3 materials with excellent catalytic and adsorption performance.