Preparation And Properties Study Of BiOBr-based Photocatalysts

With the rapid development of industry,the emission of a large amount of dye wastewater brings enormous pollution and damage to the environment and humans.Photocatalytic technology has great research prospects and applied value for the degradation of dye wastewater.BiOBr has a unique layered structure making it become a very promising photocatalyst.However,due to the fast recombination of photogenerated electrons and holes,it is necessary to further increase the photocatalytic activity.In this paper,three kinds of composite photocatalysts of g-C₃N₄/BiOBr,WO₃/BiOBr and BiON-5N/BiOBr were successfully prepared by BiOBr as the core photocatalyst,and Rhodamine B and E.coli were used as targets to evaluate the photocatalytic performance of the composite photocatalyst.At the same time,the crystal structure,micromorphology and photocatalytic properties of the photocatalyst were analyzed by some characterization methods and tests.Three works were carried out as follows:（1）g-C₃N₄/BiOBr composite photocatalysts with different weight ratios were prepared by ultrasonic water bath deposition method,and rhodamine B and Escherichia coli were degraded under visible light irradiation.The experimental results show that the photocatalyst with 20%BiOBr has the highest photocatalytic activity;the ratio of g-C₃N₄ and BiOBr has an effect on the photocatalytic efficiency;the enlargement of the redox potential and the photogenerated electron-hole pair Rapid separation promotes photocatalytic efficiency.（2）WO₃/BiOBr composite photocatalysts with different weight ratios were prepared by the ultrasonic water bath deposition method,and the degradation of rhodamine B and Escherichia coli under visible light showed that the photocatalyst with 50%BiOBr had the highest photocatalytic activity.The ratio of WO₃ and BiOBr had an effect on the photocatalytic efficiency;the increase in photocatalytic efficiency is due to the rapid separation of photogenerated electron-hole pairs.（3）BiON-5N/BiOBr composite photocatalysts with different molar ratios were prepared by one-pot method at normal temperature and pressure,and rhodamine B was degraded under visible light.The experimental results show that the photocatalyst with a molar ratio of BiON-5N/BiOBr of 1:1 has the highest photocatalytic activity;the ratio of BiON-5N and BiOBr has an effect on the photocatalytic efficiency;the improvement of photocatalytic efficiency is due to photogenerated electrons;the synergistic effect of rapid separation of hole pairs and photosensitization of the dye itself.