Single-Crystalline Porous Hematite Nanorods: Photocatalytic and Magnetic Properties

Abstract

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 α-FeOOH nanorods and ionic liquids. The ionic liquids were adsorbed on the surface of O-terminated α-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.