Synthesis and characterization of structure-controlled micro-/nanocomposite TiO₂ fibers with enhanced photocatalytic activity

A series of structure-controlled composite TiO₂ fibers combining micro- and nanostructures (hereafter, micro-/nanocomposite) were fabricated using a combination of electrospinning and calcination methods, and their photocatalytic activities were investigated. Smooth microscale fibers were obtained by electrospinning a precursor solution containing tetrabutyl titanate and TiF₄. TiO₂ nanocrystals formed on the microfibers with the help of HF which was produced from the decomposition of TiF₄ in calcination. The size and quantity of TiO₂ nanocrystals can be controlled by tuning the mass ratio of TiFi4 in the sol-gel precursor solutions and the calcination time. The obtained micro-/nanocomposite TiO₂ fibers were found to exhibit enhanced photocatalytic properties when compared with the bare microfibers. These micro-/nanocomposite structures exhibit the advantages of both the nanocrystals and microfibers, which will lead to new developments in photocatalysis.