Controlled Morphology And Properties Research Of Tungsten Bismuth Materials

With the continuous development of industry, the people’s living standard has been improved significantly. However, the environment has been severely devastated when people enjoy convenience brought by the developed industry. As is well known, environmental issues are related with people’s livelihood and governance environment is beneficial for future generations. Semiconductor photocatalysis can directly degrade the organic contaminants into nontoxic small molecules such as CO2 and H2 O. In recent years, numerous attention has been paid to this technology due to its low-carbon and environment-friendly characteristics. Among the various semiconductors, tungsten bismuth(Bi2WO6) has attracted more and more attention because it can be easily excited under visible light irradiation and exhibits high utilization of solar energy and photocatalytic performances.In this paper, specific morphology of Bi2WO6 photocatalyst was prepared using different templates. The phase structures, morphologies and optical properties of the obtained samples were studied by several characterization tools including X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM) and UV-vis diffuse reflectance spectra. The photocatalytic performances of the samples were evaluated by degrading rhodamine B. The details are as follows:(1) Flower-like Bi2WO6 was synthesized via a hydrothermal method uing block copolymer F127(EO106-PO70-EO106) as a template. The effects of pH, reaction temperature, reactiontime, and the molar ratio between F127 and Bi(NO3)3·5H2O on phase, surface morphologyand photocatalytic performance were investigated. The results indicated that reaction time could affect the morphology of the samples significantly. The photocatalytic activities of the as-prepared Bi2WO6 samples were evaluated for the degradation of Rhodamine B(RhB) under visible-light irradiation. It was found that the sample synthesized at pH=3 exhibited improved photocatalytic activity. On the basis of the evolution of the morphologies as a function of reaction time, a possible formation mechanism for the hierarchical architecture was proposed.(2) Bi2WO6 photocatalyst with different morphology were successfully fabricated via a facile hydrothermal method by using L-lysine as morphology-controlling reagent. The effects of hydrothermal temperature,time and different amounts of L-lysine on the phase structure, morphology and photocatalytic performance of the prepared Bi2WO6 samples were systematically investigated. The result shows that the hydrothermal reaction temperature and the amount of L-lysine could affect the morphology of the samples significantly. The photocatalytic activities of samples were evaluated by the degradation of RhB under 300 W xenon lamp. The result showed that the sample fabricated under the condition of pH=1, the reaction time 20 h and the temperature 160℃ exhibited the best catalytic activity.