Hydrated goethite nanorodS: VVVibration spectral properties, thermal stability, and their potential application in removing cadmium ions

Vibration spectral properties and dehydration behaviors of goethite nanorods with diameters ranging from 13 to 32 nm were investigated using infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction. All goethite nanorods were highly hydrated with physisorbed and chemisorbed water. As the diameters of goethite nanorods increased, the hydroxyl deformation vibration in the a-b plane showed a significant blue shift, while the Fe-O vibration in the a-b plane shifted to lower frequencies, indicating an enhancement of O-H bond and the ionicity of Fe-O in a-b plane. The hydrated goethite nanorods are also proved to be useful in environmental remedy because of their excellent removal ability of heavy metal ions.