Method of making coating layers containing photocatalyst and a photocatalyst coating glass formed thereby

A method of making a coating layer containing a photocatalyst, comprising:

• providing a coating layer of a composition (i) or (ii) on a surface of a glass;
• and
• providing a coating layer of a composition (I) or (II) on said coating layer;
• wherein the composition (i) is a coating composition containing at least one component (a) selected from the group consisting of an organosilane, a hydrolyzate of the organosilane, and a condensate of the organosilane represented by Formula 1
• (R1)nSi(OR2)4−n (1)
• wherein
• R1 is a monovalent organic group having 1 to 8 carbon atoms, when two R1 exist, they are either identical to or different from each other;
• R2 is an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 6 carbon atoms, when two R2 exist, they are either identical to or different from each other;
• and
• n is an integer ranging from 0 to 2;
• wherein the composition (ii) is a coating composition containing the component (a) and a polymer component (b) having a silyl group having silicon atoms bonded with a hydrolytic group, a hydroxy group or both;
• wherein the composition (I) is a coating composition containing the component (a) and a photocatalyst (c);
• and
• wherein the composition (II) is a coating composition containing the component (a), the component (b), and the photocatalyst (c);
• with the proviso that compositions (I) and (II) do not contain a hydrolyzed polycondensate of a tetraalkoxysilane, a colloidal silica, a metal oxide gel or a sol thereof and a metal hydroxide gel or a sol thereof.