摘要
Cerium-doped SiO2/TiO2 nanostructured fibers were fabricated by electrospinning technology. The prepared fibers were characterized by thermogravimetric analysis （TGA）, scanning electron microscopy （SEM）, X-ray diffraction （XRD） and Fourier transform infrared spectroscopy （FT-IR）. Using the fibers as catalysts, photoeatalytic degradation of Methylene Blue （MB） aqueous solution was carded out under simulated sunlight. The 0.2% Ce doping proved to be the optimal concentration for the doping of TiO2/SiO2, compared to other Ce-doped molar concentrations. The 0.2% Ce-doped SiOdTiO2 fibers exhibited higher photocatalytic activity than industrial Degussa P25 and the samples doped with only Ce or SIO2. The reasons for improving the photocatalytic activity were also discussed. Several operational parameters were studied, which showed that the photocatalytic efficiency of MB was influenced by parameters such as the initial dye concentration, the initial pH, inorganic anions, and so on. In addition, the influences of an electron acceptor and a radical scavenger suggested that OH was the dominant photooxidant during the photocatalytic process. The reuse evaluation of the fibers indicated that their photocatalytic activity had good stability.
Cerium-doped SiO2/TiO2 nanostructured fibers were fabricated by electrospinning technology. The prepared fibers were characterized by thermogravimetric analysis （TGA）, scanning electron microscopy （SEM）, X-ray diffraction （XRD） and Fourier transform infrared spectroscopy （FT-IR）. Using the fibers as catalysts, photoeatalytic degradation of Methylene Blue （MB） aqueous solution was carded out under simulated sunlight. The 0.2% Ce doping proved to be the optimal concentration for the doping of TiO2/SiO2, compared to other Ce-doped molar concentrations. The 0.2% Ce-doped SiOdTiO2 fibers exhibited higher photocatalytic activity than industrial Degussa P25 and the samples doped with only Ce or SIO2. The reasons for improving the photocatalytic activity were also discussed. Several operational parameters were studied, which showed that the photocatalytic efficiency of MB was influenced by parameters such as the initial dye concentration, the initial pH, inorganic anions, and so on. In addition, the influences of an electron acceptor and a radical scavenger suggested that OH was the dominant photooxidant during the photocatalytic process. The reuse evaluation of the fibers indicated that their photocatalytic activity had good stability.
基金
supported by the National Natural Science Foundation of China (No. 20907022,21003094)
the Doctoral Program of Higher Education of China(No. 200800551003,20100032120066)
the Special Projects of Environmental Protection (No. 2009ZX07526,2009ZX07208,200909101,2009GJA10021)
