The photocatalytic activity of a series of titanium dioxides in the oxidati
on of X - 3B pigment is investigated. The factors including crystallite siz
e, lattice distortion and anatase content that influence the photocatalytic
activity of titanium dioxide dispersion are discussed in detail. We propos
e that lattice distortion that inhibits the hole and electron pair recombin
ation dominates the above factors and to some extent determines the photoca
talytic efficiency of titanium dioxide dispersions.