Controlled morphology synthesis of beta-FeOOH and the phase transition to Fe2O3

摘要

The hexagram and arrayed beta-FeOOH nanorods were first synthesized free of surfactants through the solvent-thermal method. Xray powder diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectrum (EDAX) and thermal gravimetric analysis (TGA) were used to characterize the as-prepared products. The TEM and FESEM images showed that hexagram beta-FeOOH and arrayed rod-like beta-FeOOH with an average diameter of 10-15 nm and an average length of 100 nm (aspect ratio is about 10) were prepared. Electrochemical tests show that these nanorods deliver a large discharge capacity of 277 mA h g(-1) versus Li metal at 0.1 mA cm(-2) (voltage at 1.5-4.2 V). Treated the as-synthesized rod-like beta-FeOOH by annealing, rhombus hematite was obtained. (c) 2005 Elsevier Inc. All rights reserved.