Synthesis and characterization of rice grains like Nitrogen-doped TiO2 nanostructures by electrospinning-photocatalysis

Rice grain-shaped Nitrogen-doped titanium dioxide (N-TiO2) nano/mesostructures were fabricated through a combination of sol-gel and electrospinning methods. As-spun nanofibers were continuous and upon thermal treatment at 500 degrees C for 1 h in air, the continuous fibers break into rice grain-shaped TiO2 nanostructures of average diameter 50-80 nm. The nanostructures were characterized by spectroscopy, microscopy and powder X-ray diffraction. The rice grains consist of spherical particles of average diameter of similar to 18 nm and with N doping, their average diameters decrease from similar to 18 to similar to 12 nm. The presence of N in the TiO2 lattice was confirmed by X-ray photoelectron spectroscopy (XPS). The band-gap of TiO2 reduced from 3.19 eV to 2.83 eV upon increasing doping level of N from 0% to 5% (w/w), respectively. The N-TiO2 rice grains showed an enhanced UV light-assisted photocatalysis compared to pure TiO2 in the photodegradation of Alizarin Red S dye, an industrially important anthraquinone dye. (C) 2011 Elsevier B.V. All rights reserved.