Low temperature formation of AlN nanofibers by carbothermal reduction nitridation of hydrothermal precursor fibers

AlN nanofibers were fabricated by carbothermal reduction (CRN) method of hydrothermal precursor fibers using aluminum nitrate, urea, glucose and polyethylene glycol as raw materials. The as-fabricated samples were characterized by TG-DSC, XRD, SEM, EDS, and UV-vis absorption and PL spectra. The results indicated that raw materials were transformed to NH4Al[(OOH)HCO3] (AACH) fibers in hydrothermal process, carbon coated γ-Al2O3 fibers in decomposition process, and AlN nanofibers in CRN process. In relation to other CRN methods, the hydrothermal precursors reduced the fabrication temperature in 200 °C. The diameter of the AlN nanofibers fabricated at 1400 °C was 90-110 nm with several micrometers length. These fibers showed broad absorption band from 190 to 230 nm with an absorption edge at 198 nm and obvious emission at approximately 478 nm and 577 nm excited by 350 nm, indicating a valuable application in light-emitting nanodevices. Such a strategy can be extended to synthesize other nitride fibers.