A method of making a coatable composition includes: providing a first composition comprising silica nanoparticles dispersed in an aqueous liquid vehicle, wherein the silica nanoparticles have an average particle size of less than or equal to 100 nanometers, wherein the first composition has a pH greater than 6; acidifying the first composition to a pH of less than or equal to 4 using inorganic acid to provide a second composition; and dissolving at least one metal compound in the second composition to form the coatable composition, wherein said at least one metal compound comprises a titanium compound. Coatable compositions and photocatalytic compositions, preparable by the method, are also disclosed. Photocatalytic articles including the photocatalytic compositions are also disclosed.