Commercial nano-sized TiO2 powder (P25) coated with commercial CoO2 powder by a sonochemical method was immobilized on foamed waste-glass substrates using plasma spraying coating technology. The immobilized TiO2-CoO2 coatings were applied to treat both green tide and red tide samples under the illumination of an UV light. Their photocatalytic characterizations were evaluated as functions of the number of residual algae, the transmission as well as the pH value with illumination time. It was found that the plasma sprayed 1 mol% CoO2-doped TiO2 nanostructured coatings on foamed wasteglass showed higher photocatalytic activity, which was effective to treat the green tide and red tide samples.

Keywords: Plasma spraying, TiO2-CoO2 coating, Photocatalytic activity, Foamed waste-glass, Algae.