1.2.4考古: V1 (710) Fourth Topic: The effect of TiO2 (a chemical) Par1: TiQ2 is a chemical that can help disolve pollutants, and it went on to explain how Par2:Mentioned through two examples, one in Japan and the other in Hong Kong, that people are finding new ways to use TiO2 to fight pollution. The HK example is about using TiO2 to absord waste gas from cars on the stree. Par3: However, it is not very easy to apply TiO2 because it only works when reacts with a very small portion of the spectrum from the sun light.