This paper aims at the investigation of photocatalytic properties of titanium dioxide coatings covering on the surfaces of long blue-emitting afterglow CaAl2O4:Eu2+, Nd3+ elaborated by a sol-gel method. Morphologies and microstructures of the coatings were observed mainly by transmission electron microscopy (TEM) and analyzed by X-ray diffraction (XRD). The photocatalytic behavior of the TiO2-base surfaces was evaluated by the degradation of methyl orange (MO) solution. It suggested that a layer of TiO2 film mounted on the phosphor particles successfully. Also, the TiO2 coatings had remained its photocatalytic role on the as-prepared sample even after the light source was removed. The inner long blue-emitting afterglow had released blue afterglow after removing light source and allowed for reactive TiO2 surfaces to be held for the removal of methyl orange.