Single-Crystalline Porous Hematite Nanorods: Photocatalytic and Magnetic Properties

Single-crystalline hematite nanorods with void pores were synthesized by a facile hydrothermal process and subsequent heat treatment in air. The pores were formed by removal of released H2O in alpha-FeOOH nanorods and ionic liquids. The ionic liquids were adsorbed on the surface of O-terminated alpha-FeOOH nanorods by electrostatic force, and hydrogen bonds formed between the hydrogen atom at the C2 position of the imidazole ring and the oxygen atom of O-Fe. The proposed formation mechanism has been investigated on the basis of the TEM image and SAED pattern. Hematite with a different porosity and degree of crystallinity has a different photocatalytic property for the photodegradation of methyl orange. The temperature-dependent magnetization and magnetic hysteresis of samples indicate the interesting magnetic property evolution, which is attributed to the finite size and surface effect of the pore-solid architecture created by void pores in the rods.