A novel atmospheric pressure hydrolysis without stirring and combustion–calcination process for the fabrication of magnetic Fe3O4/α-Fe2O3 heterostructure nanorods

Abstract

Atmospheric pressure hydrolysis without stirring and a combustion–calcination method were utilized to fabricate magnetic Fe _3 O _4 / α -Fe _2 O _3 heterogeneous nanorods. First, the β -FeOOH nanorods were fabricated via hydrolysis, and the concentration of Fe ^3+ , hydrolysis temperature, and hydrolysis time were optimized. The optimal fabrication conditions were as follows: a 0.1 M FeCl _3 solution was hydrolyzed at 90 °C for 2 h. The average length and diameter of the β -FeOOH nanorods fabricated under the optimal conditions were approximately 216 and 58 nm, respectively. Subsequently, Fe _3 O _4 / α -Fe _2 O _3 heterogeneous nanorods were fabricated via a combustion–calcination process. The volume of absolute ethanol, calcination temperature, and calcination time were investigated to optimize the fabrication conditions of Fe _3 O _4 / α -Fe _2 O _3 heterogeneous nanorods under the following conditions: absolute ethanol: 50 ml; calcination temperature: 300 °C; and calcination time: 2 h. Magnetic Fe _3 O _4 / α -Fe _2 O _3 heterogeneous nanorods fabricated under optimal conditions were characterized with an average length of 199 nm, an average diameter of 51 nm, a zeta potential of +17.2 mV, and a saturation magnetization of 13 emu·g ^–1 .

Keywords

• β-FeOOH nanorods
• magnetic Fe3O4/α-Fe2O3 heterogeneous nanorods
• atmospheric pressure hydrolysis
• combustion-calcination method