The Design Synthesis And Performance Research Of Nano-photocatalyst

In this dissertation, monodisperse spindle-like FeW04and Fe2.25W0.75O4nanoparticles have been successfully synthesized by the soft solution-based routes and their various properties were studied as nano-photocatalyst, respectively. The main results can be summarized as follows:1. Monodisperse FeWO4nano-photocatalyst with specific spindle-like morphology have been synthesized in the presence of citric acid as surfactant through a soft hydrothermal process. In the synthesis route, citric acid played four roles such as the reducing agent, clelating regent, structure-directing agent and stabilizing agent. In addition, the morphology of FeW04was dramatically tuned by the pH value of the precursor medium. The optical properties of FeW04were investigated with UV-Vis spectra and photoluminescence spectroscopy. The photocatalytic experiments demonstrated that the decomposition efficiency of the monodisperse spindle-like FeW04nanoparticles is74%after30min of UV irradiation, which displayed remarkable enhanced photodegradation activity compared with ordinary FeWO4sample (57%) and normal TiO2photocatalysts P-25(56%).2. W has been successfully doped in Fe3O4host matrix for the fabrication of Fe2.25W0.75O4nanoparticles through a one-pot hydrothermal progress with the addition of sodium dodecyl benzene sulfonate as surfactant. X-ray diffraction analysis clearly shows that all peaks of Fe2.25W0.75O4nanoparticles shift slightly toward lower angles relative to those of the standard Fe3O4, which resulted from the substitutions of Fe ions by the bigger W ions in the host lattice. And the particle size is about41nm calculated with Debye-Scherrer equation. When Fe2.25W0.75O4nanoparticles were applied to degrade methyl orange under the irradiation of a10W UV lamp, it showed a higher decomposition efficiency of67%than that of55%for normal TiO2photocatalysts P-25. Moreover, Fe2.25W0.75O4nano-photocatalyst can be conveniently and quickly recovered from the solution with a magnet after degradation and no decrease of photocatalytic activity has been observed after several consecutive rounds of photodegradation rection. SEM confirmed that its structure is not destroyed after continuous cycle5times in order to achieve photocatalyst recycled, reducing the waste of resource. The magnetic new dual function Fe2.25W0.75O4nano-photocatalyst with strong photocatalytic ability show promising applications in the photocatalytic treatment of organic wastewater field.3. Loading the product of above2on the grapheme oxide, use the conductive capacity of grapheme oxide to separate excited electron and hole rapidly. Reducing the composite of excited electrons and holes, thus enhancing the photocatalytic properties of the product. The experimental results show that the obtained product reaches the desired design effect, photocatalytic activity increased, and continued to maintain good magnetic properties, for photocatalytic into actual field provides the experimental reference.