Porous tubular rutile TiO2 nanofibers: synthesis, characterization and photocatalytic properties.

Electrospinning was employed to synthesize tubular TiO2 nanofibers. The as-spun fibers were subjected to heat treatment at 800 degrees C for 1 h in the air. By controlling the polymer concentration, pores measuring 30-60 nm were formed on the side walls of the tubular nanofibers. During annealing, the average nanofiber diameter shrank from 150 nm to 120 nm. The structural properties were characterized by XRD, Raman and FTIR spectroscopy. Further porous and tubular structures were confirmed by SEM and HRTEM. The specific surface area of porous tubular nanofibers (PTNFs) was measured using the Brunauer-Emmett-Teller (BET) method, which revealed a high surface area of 63 m2 g(-1). Photodegradation of methyl orange demonstrated that the PTNFs have higher photocatalytic activity than nonporous nanofibers. This enhanced photocatalytic activity can be attributed to the high surface area of the porous and tubular structures.