|Various measures have been developed against sources of air, water and soil pollution and have proven effective to a certain degree, however, as shown in the below Fig. 1, there are still some unsolved problems with regards to air pollution and yet other new problems such as hazardous chemical substances have arisen. In addition to developing economically feasible measures for energy and resource conservation that are applicable to small to medium size sources of pollution, it is necessary to develop technology to directly clean polluted environments (environmental purification technology).|
A photocatalyst can break down and remove a variety of environmental (load) pollutants at room temperature by oxidation, using sunlight or artificial light as an energy source. It is being targeted for practical application as a new environmental protection technology.