The Preparation Of TiO₂/MoO₃Composite Nanofibers And Its High Photocatalytic Properties

In recent years, with the increasing environmental pollution, industrial wastewaterpolluting water has become a main reason for the global water resources deficiency.Therefore, wastewater treatment has also become a key research issue for researchers ofdifferent nations. TiO₂, as a photocatalyst, is widely used to treat a variety of organicpollutants in industrial wastewater for its features of cheapness,availability, chemicalstability,avirulence and relatively high catalytic reactivity. But the rapid recombination ofphotogenerated electron-hole pairs in the process of reaction reduce the catalyticefficiency of TiO₂.According to research, semiconductor nanocomposite can effectivelysolve the problems of the high recombination rate. According to the problem, in thispaper, TiO₂-MoO₃nanofibers were obtained by a two-step fabrication method.By using the electrospun TiO₂nanofibers as hard template and through hydrothermalmethod, TiO₂-MoO2Composite Nanofibers were prepared. Through heat treatment of theas-prepared TiO₂-MoO2Composite Nanofibers, the MoO2phase of the TiO₂-MoO2Composite Nanofibers changed to MoO₃, then the TiO₂-MoO₃Composite were obtained.The as-obtained products were characterized by X-ray diffraction （XRD），field emissionscanning electron microscopy （FE-SEM）, energy-dispersive X-ray （EDX） spectroscopy,transmission electron microscopy （TEM）, diffuse reflectance spectra （DRS）, X-rayphotoelectron spectroscopy （XPS） and photoluminescence spectroscopy （PL）. The resultsrevealed that, the morphology and loading of the secondary MoO2nanostructures（nanoparticles or nanosheets） of the TiO₂-MoO2Composite Nanofibers could becontrolled by adjusting the concentration of molybdenum precursor in the hydrothermalprocessing. And, the obtained MoO₃of TiO₂-MoO₃Composite Nanofibers possesssimilar morphology as compared with that of the TiO₂-MoO2Composite Nanofibers,which implied that the crystal growth of MoO₃was directed by the MoO2of theTiO₂-MoO2Composite Nanofibers in the heat-treatment processing. The photocatalytictests shown that the TiO₂-MoO₃composite nanofibers nanofibers possessed a muchhigher degradation rate of Rhodamine B （RB） than that of pure TiO₂nanofibers andMoO₃nanoparticals under UV light. The enhanced photocatalytic activity of TiO₂-MoO₃composite nanofibers might be attributed to the effective separation of photogeneratedcarriers driven by the photoinduced potential difference generated at the TiO₂-MoO₃ heterostructures interface. The TiO₂-MoO₃composite nanofibers could be reclaimedeasily by sedimentation from the photocatalytic reaction solution due to the large lengthto diameter ratio of the one-dimensional structures.