α-Fe2O3 nanoplates: PEG-600 assisted hydrothermal synthesis and formation mechanism

Quasi-hexagonal alpha-Fe2O3 nanoplates with lateral sizes of 40-60 nm and thickness of ca. 10 nm were fabricated by a facile poly(ethylene glycol 600) (PEG-600) assisted hydrothermal technique in combination with calcination method. The final alpha-Fe2O3 nanoplates inherited perfectly the morphology of the preliminarily hydrothermal products with phases of dominant alpha-Fe2O3 and minor alpha-FeOOH. The platelets could be tailored from nano- to meso- and to micro-scale via adjusting PEG-600 quantities. An adsorption-extension-attachment model was proposed to explain the formation and growth mechanism of the platelets. The as-obtained alpha-Fe2O3 nanoplates exhibited a specific Langmuir surface area of 59 m(2)/g and a maximum N-2 adsorption of 137.3 cm(3)/g at 1 atm. UV-vis measurement showed a strong absorption in a wide range from UV to visible light with a blue-shifting band gap of 2.33 eV due to the nanosize effect. (C) 2010 Elsevier B.V. All rights reserved.