Phase Controlling of TiO2 Fibers by Adjusting Precursor Pre-Hydrolysis and Calcined Process Towards Enhanced Photocatalysis

TiO2 fibers with controlling phase composition were fabricated by an electrospinning route and a subsequent calcined process. The pre-hydrolysis of precursor was carried out to create dense TiO2 fibers for the first time. The degree of the pre-hydrolysis plays an important role for the controlling of electrospinning process. Different heat-treatment parameters were applied to adjust the phase proportions of anatase and rutile in TiO2 fibers. The phase composition of the fibers was ascribed not only to the heat-treated rate, time, and temperature, but also to the degree of precursor pre-hydrolysis as well. Even though heat-treating at 650 °C, TiO2 fibers still revealed a mixture phase composition of anatase and rutile. Dense TiO2 fibers with unique morphology and size were fabricated using optimal preparation conditions. The photocatalysis performance of the fibers was evaluated according to the photodecomposition of methyl orange under ultraviolet light irradiation. Photocatalytic degradation rate was estimated by kinetic constants. The photocatalytic performance of TiO2 fibers depended strongly on their phase compositions. These dense TiO2 fibers with different phase compositions would be utilizable for various applications.