Photocatalytic Activity of Al-TiO2 Nanomaterials for the Degradation of Methylene Blue Dye

Al-TiO2 nanofibers and nanotubes having an Al/Ti molar ratio of 0.38 were prepared using solgel-derived electrospinning to investigate the effect of Al doping on the crystal structure and the photocatalytic activity of methylene blue (MB). X-ray diffraction (XRD) results indicated that Al-TiO2 nanofibers and nanotubes were composed of anatase (47%, 43%) and rutile (53%, 57%) phases, respectively. As the Al-TiO2 nanotubes were electrospun whereas the Al-TiO2 nanofibers were not, the Barrette-Emmett-Teller (BET) surface area and degradation kinetic constant increased dramatically from 147 m2/g to 151 m2/g and from 7.7 × 10 −3 min −1 to 2.0 × 10 −2 min −1, respectively. The Al-TiO2 nanotubes calcined at 500 °C exhibited enhanced MB degradation (93%) compared with that of TiO2 nanofibers (8%) due to the synergic combination of mixed crystals, larger BET area, and Al doping.