The well known of photocatalyst is its strong catalytic degradation effect, which can effectively degrade hazardous substances in the air; to kill a variety of bacteria, furthermore to decompose and harmless treat the released toxins of fungi or bacteria; at the same time, it also has the functions like removing formaldehyde and odor, anti-dirt, air purification ect.. However, what you do not know is that it can also be used for the synthesis of inorganic materials, such as H₂, I₂and NH₃ and so on.

 

Since the first case of titanium dioxide photocatalytic dissociation of water to produce hydrogen, once the photolysis of water into hydrogen has boomed worldwide, a variety of researches and reports of photocatalyst catalytic decomposition of water into hydrogen are emerged in endlessly. In 1980, some researchers set NaOH onto the surface of platinum and titanium dioxide, and carried out a photolysis experiment in water vapor, and found the phenomenon of hydrogen and oxygen produced simultaneously; nitrogen and hydrogen under the action of the photocatalyst, placed under the conditions of 100W mercury lamp, atmospheric pressure, temperature of 82~86°C, NH₃ will be synthesized; however, the current photocatalytic synthesis yield of NH₃ is still very low. But, because it carries out in a very mild reaction conditions, maybe some kinds of inspire will be on the new artificial nitrogen fixation patterns.

 

Tungsten trioxide, the yellow powder, with various properties such as photochromic and gas sensitive, often used for architectural glass, toxic gas detection and other aspects; a large number of it used for the preparation of metal tungsten, WC and carbide ect.; at the same time, it is also often used in the preparation of denitration catalyst. Tungsten trioxide is one kind of photocatalyst with excellent performance, especially WO₃/CdS, WO₃/Fe₂O₃and other coupled diodes can effectively improve the photocatalytic effect; by coupling semiconductors, the charge separation effect of the system can be improved, and thus to expand the spectral absorption range, thereby increasing the photocatalytic activity. Tungsten trioxide because of its narrow band gap, compared with titanium dioxide, it can use the visible light more efficiently, and thus, have a wider application.