Titanium dioxide hollow nanofibers for enhanced photocatalytic activities

Abstract

One-dimensional photocatalysts with enhanced properties are desirable for photocatalytic degradation of organic pollutants. In this work, hollow titanium dioxide nanofibers (HTNF) were successfully prepared via template synthesis technique. Firstly, polyacrylonitrile (PAN) nanofibers were synthesized by electrospinning and oxidized for further use. By dip-coating the electrospun nanofibers in TiO2 sol–gel, TiO2/PAN nanofibers composite was obtained. Subsequently, the nanocomposite was calcined. The decomposition of PAN during calcination resulted in the formation of HTNF. The nanofibers were characterized by FESEM, TGA and XRD. The characterization revealed hollow nanofibers structure with diameter of 200–250 nm. XRD analysis showed that the nanofibers had mixed crystalline phase, with 24.2% anatase and 75.8% rutile. The photocatalytic performance of HTNF were studied by evaluating the degradation of Bisphenol A (BPA) under UV light irradiation. In the photodegradation process, the effect of several parameters such as the initial concentration of BPA, pH of the solution and photocatalyst dosage were investigated. The optimum photocatalyst dosage, pH and initial BPA concentration were 0.75 g/L, pH 4.1 and 10 ppm BPA, respectively. Under these conditions, the photocatalytic performance of HTNF were found to be 97.3%, which was 12.6% higher than those of Degussa P25 TiO2. The degradation of BPA followed the pseudo-first-order kinetic model.