Continuous hollow alpha-Fe2O3 and alpha-Fe fibers prepared by the sol-gel method

Continuous iron oxide gel fibers were prepared by the sol-gel method using ferric alkoxide and acetic acid as starting materials and alcohol as solvent, and continuous hollow alpha-Fe2O3 fibers produced after the gel fibers were heat treated at 400degreesC for 1 h. The outer diameter of the alpha-Fe2O3 fibers is between 4-10 mum and the wall thickness is 1-2 mum, in which the alpha-Fe2O3 particle size is about 100 nm. 2-Methoxyethanol and acetic acid played important roles in the formation of the spinnable sol and the possible mechanism for the formation of the hollow alpha-Fe2O3 fibers was discussed in detail. The hollow alpha-Fe fibers could be obtained by reducing the as-prepared alpha-Fe2O3 fibers under hydrogen flow and the alpha-Fe particle size increased to similar to150 nm.