Preparation of continuous porous alumina nanofibers with hollow structure by single capillary electrospinning

Porous alumina nanofibers with hollow structure were fabricated by single capillary electrospinning of aluminum nitrate (Al(NO3)3)/polyacrylonitrile (PAN) precursor solution, followed by sintering treatment. The Al(NO3)3/PAN composite nanofibers and sintered nanofibers were characterized by scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). It is found that the obtained alumina nanofibers show porous external surfaces and hollow sections. Upon sintering the composite nanofibers at 1300 °C, the nanofibers are consisted of α-phased crystalline grains. Sintering temperature plays an important role in controlling the morphology and crystal structure of the nanofibers. A mechanism based on “Kirkendall effect” was proposed to explain the formation process of the hollow structure.