Abstract:
A silica gel which carries a titanium oxide photocatalyst in high concentration, characterized in that it has an average micropore diameter of 6 to 100 nm and it has a gradient of titanium oxide concentration such that a titanium oxide content of a micropore located in the vicinity of the surface of a silica gel particle is 7 to 70 wt % and is no less than 1.5 times that of a micropore located in the vicinity of the central portion of the particle; and a method for preparing the same. The silica gel has a gradient of titanium oxide concentration wherein a titanium oxide content is higher in the vicinity of the surface of a particle and lower in a central part thereof, which results in the improvement of the ability to decompose environmental pollutants or the like such as a malodorous or hazardous substance contained in air, an organic solvent contained in water and an agricultural chemical, and also has various excellent characteristics from view points of safety, economy, stability and resistance to water (no crack when placed in water).