The perovskite(ABO 3) type oxides have a photocatalytic activity that can be characterized with decolorization of some organic dyes under irradiation of mercury lamp. The experimental results show that the photocatalytic activity of ABO 3 increases with increasing atomic number of atom B(Ti—Co) when A site atom keeps constant. It is connected with the rise of Allred Rochow electronegativity of atom B, the decrease of ABO 3 energy gap(energy defference between the filled p bands of O 2- and the unoccupied 3 d band of neighboring atom B) and the increase of the third atomic ionizaton potentials of atom B. It has been also proved that the photocatalytic activity of ABO 3 compounds increases with increasing χ AR of atom A(Ca, Cd, Pb).
