The Bi <sub> 25 </ Sub> Feo <sub> 40 </ Sub> And Bi <sub> 25 </ Sub> From Feo <sub> 40 </ Sub>-bi <sub> 2 </ Sub> O < Sub> 3 </ Sub> Composite Photocatalyst Prepared By Microwave Meth

With the rapid economic development and scientific and technological progress, people's demands for water quality and quantity are increasingly, which also increase the burden on the environment. Water pollution is more and more serious. Photocatalytic materials have important applications in solving environmental problems. Compared with traditional environment management methods, photocatalytic materials can decompose organic pollutants into carbon dioxide and water, which, have the virtues of low cost, efficient and no secondary pollution. Bi2O3 is an important semiconductor photocatalyst with bandwidth of 2.85 eV. Bi2O3 can degrade organic pollutants in the visible light, so it have more applications that can be used instead of TiO2 and have broad application prospects. The sillenite crystal structure of Bi25FeO40 have no center of symmetry, belong to the space group 123. Bi25FeO40 has large amounts of defects in crystal structure, which lead to a nonlinear optical effect and piezoelectric effect, in the visible light transmission and excellent catalysis application. For these reasons, the paper prepared Bi25FeO40 by microwave synthesis and developed a high photocatalytic activity of Bi25Fe04o and mixed with Bi2O3 catalyst. The main contents include:(1) Bi25FeO40 was synthesized in a relatively short time using microwave synthesis. X-ray diffraction (XRD) and infrared spectroscopy (IR) indicated that:When changing the feed ratio of iron to 8% and 10% the pure phase Bi25FeO40 can be obtained. By the UV-visible diffuse reflectance spectroscopy can be seen, Bi25Fe04o optical direct band gap was 2.45 eV, which was in accordance with the Bi25FeO40 prepared by hydrothermal method in the literature.(2) Bi25Fe04o-Bi203 composite catalyst was prepared by the microwave synthesis. The products were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR) and atomic absorption spectrometry. The results show that the iron feed ratio, NaOH concentrations has a great influence on the composition of the product. With the feed ratio of iron increases, Bi25Fe04o proportion in the product increases. When the feed ratio of iron is 10%, a new hybrid phase Bi24Fe2O39 yield. When concentration of NaOH is lower, the product contains more Bi2O3. When concentration of NaOH is highter, the product contains less Bi2O3. The photocatalytic activity of the products showed that:the product with the preparation condition that the feed ratio of iron 3%, NaOH concentration 0.3 M had the highest photocatalytic activity.The mass fraction of Bi25FeO40 in the product was 31.95%.This may be due to the synergistic effect of Bi2O3 and Bi25FeO40 improving its photocatalytic activity.