TiO2 hollow nanofibers have been fabricated by directly annealing electrospun polyvinylpyrrolidone (PVP)/Tetra-butyl titanate (TBT) composite nanofibers. In this approach, PVP/TBT composite fibers were first synthesized by electrospinning PVP/TBT solution, and then calcined at high temperature with an appropriate heating rate to form hollow TiO2 nanofibers. During the heat treatment, the solvent composition, the amount of TBT and the heating rate have important influences on the morphologies of the TiO2 nanofibers. Morphologies of TiO2 could be...