Bismuth Tungstate Powder Photocatalyst Preparation by Microwave Hydrothermal Method

In the study of photocatalysis of bismuth tungstate, scholars believe that morphology control has always been a research hotspot in nanomaterials. As the simplest layered Aurivillius oxide, Bi₂WO₆ has a layered structure, which is most conducive to the formation of two-dimensional structure. The reaction conditions of synthesis can be controlled to obtain complex multi-level structure, so as to improve its photocatalytic performance. Therefore, a new preparation method upgraded to hydrothermal synthesis came into being, which is called microwave hydrothermal method.

Microwave hydrothermal method combines the unique heating characteristics of microwave and the advantages of hydrothermal method. It has the incomparable advantages of other traditional synthesis technologies. It has the advantages of fast reaction speed, short synthesis time, mild reaction conditions, high reaction efficiency, high purity and narrow particle size distribution. Microwave hydrothermal method is used to prepare porous and loose wool-like bismuth tungstate powder photocatalyst. Technical solutions include:

Step 1: Weigh Bi (NO₃)₃·5H₂O and Na₂WO₄·2H₂O into beaker, add appropriate deionized water to beaker, make Bi (NO₃)₃·5H₂O concentration 0.05mol/L, Na₂WO₄·2H₂O concentration 0.025 mol/L.

Step 2: Adjust the pH = 1.6, magnetic stirring at room temperature for 1 hour to make the raw materials mix evenly, and get the precursor of microwave hydrothermal reaction.

Step 3: Put the precursor solution into the PTFE lined reactor, then put the reactor into the microwave hydrothermal reactor, set the power of 300W, and react at 180 ℃ for 60 minutes before stopping the reaction.

Step 4: After the reaction temperature drops to room temperature, the precipitate in the reactor is removed; the precipitate is washed to neutral with water and absolute ethanol; and the porous and loose wool-like bismuth tungstate powder photocatalyst is obtained after drying for 10 hours at 80 ℃.

The morphology of bismuth tungstate powder photocatalyst prepared by microwave hydrothermal method is layered porous loosely wool cluster composed of thin sheets. The morphology of layered porous loosely wool cluster is advantageous not only to the adsorption of organic matter, but also to the diffuse reflection of light in the powder catalyst and to the improvement of the utilization of light energy.

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