Tungsten oxide powder not only has photochromic properties, but also has photocatalytic properties. Therefore, it can be used in the field of window heat insulation film and photocatalytic degradation of organic pollution. However, the photocatalytic performance of tungsten trioxide needs to be further improved to make it better applied in the field of catalysis. And the method for improving the photocatalytic performance of WO3 includes elemental doping and the like.
For example, S, I-doped tungsten trioxide may be prepared by spray pyrolysis method. And it is found that the forbidden band width of tungsten trioxide after doping is reduced from 2.7eV to 2.6eV and 2.1eV, respectively. It means that doping makes the light absorption range of tungsten trioxide widened. However, it is found that the activity of I-doped tungsten trioxide is reduced although the doping of I (Iodine) makes the band gap of the catalyst become narrower, as the deep level of I becomes a recombination center of photogenerated carriers. While S (Sulfur) doping does not produce this deeper energy level, so S doping can improve the photocatalytic activity of tungsten trioxide.
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