Tungsten trioxide has been researched a lot, because of its unique physical and chemical properties, such as electrochromic, gas properties, photoluminescence. In addition, the tungsten oxide has non-toxic, and narrow band gap (2.4eV ~ 2.8eV), as a semiconductor material used in the visible light photocatalyst catalytic reactions of organic matter in sewage catalytic degradation. Hollow structural material has both inner and outer surfaces, and can take advantage of multiple reflections of light into the interior, which has a unique application.

 

Studies have shown that tungsten trioxide hollow ball prepared at lower temperature has the advantages not only improve utilization of light sources of catalyst, but also reduced the cost of catalyst. The method for preparing tungsten oxide hollow balls is as follows:

1. Weigh the appropriate amount of curing polystyrene microspheres, and then ultrasonic disperse it in anhydrous ethanol to form a colloidal solution;

2. Weigh the appropriate amount of tungsten hexachloride (WCl₆), then add into the colloidal solution obtained in Step 1, then the turns from white to yellow;

3. After the WCl₆ completely dissolved, slowly add the appropriate amount of deionized water, then the solution turns dark blue;

4. Place the system in a water bath at 70 ° C for stirring mechanically for 24 hours, cool down to the room temperature;

5. Centrifuged and washed several times with deionized water, then dried in 60°C, then placed in a muffle furnace for a heat treatment, wherein the heat treatment process: first calcined at 200 ° C for one hour, so that to completely decompose the sulfur polystyrene microspheres, and then calcined at 300°C for 3 hours, and finally we get hollow ball tungsten trioxide photocatalyst (Microscopic observation that the surface is roughness, an has portion of tungsten oxide hydrate).

Noted: the mass ratio of vulcanization polystyrene microspheres and WCl₆is 1: 2; and the volume ratio of anhydrous ethanol which is added and deionized water is 4: 1; and mass of WCl₆(g) and ratio of anhydrous ethanol (mL) is 1: 100.

 

Testing showed that the prepared hollow balls tungsten trioxide as photocatalyst, the photocatalytic degradation rate of Rhodamine B (RhB) can reach 86.61% (after 60 minutes of illumination).