Controllable Synthesis of Porous α-Fe2O3 Microtube and Tube-in-tube by Non-coaxial Electrospinning

We present a facile non-coaxial electrospinning technique to synthesize the porous α-Fe2O3 microtube and tube-in-tube. The possible formation mechanism of different tubular-structure α-Fe2O3 has been proposed. Among the experimental parameters, the heating rate during calcination is a key factor for realizing different α-Fe2O3 structures. The slower heating rate is of benefit to form α-Fe2O3 fiber with tube-in-tube structure. This method is versatile and can be extended to construct other hollow and multitubular metal oxide nanofibers, such as ZrO2, SiO2, SnO2, and In2O3 tube-in-tubes.