Anatase TiO2 powder immobilized on reticulated Al2O3 ceramics as a photocatalyst for degradation of RO16 azo dye

Abstract

The three-dimensional network of open-celled Al2O3 ceramic supports were first fabricated using a polymeric sponge replication technique. The polyurethane foams soaked with the highly loaded Al2O3 ceramic slurry were drained, slowly dried and sintered at 950 degrees C to complete the burn out process and to construct the ceramic preforms. They were then carefully soaked again with the moderately loaded Al2O3 slurry and sintered at 1500 degrees C to increase their strength. Finally, the photocatalyst ceramic powder covering the outer surfaces was placed layer by layer through dipping the rigid Al2O3 supports repeatedly in the slurry of TiO2 powder. The dipapplied TiO2 was sintered eventually at relatively low temperature of 700 degrees C to prevent phase transformation. The efficiencies of the TiO2 coated Al2O3 samples were evaluated by the photocatalytic degradation of reactive orange 16 (RO16) azo dye molecules dissolved in water. Nearly complete color removals were achieved within 75 min under UVC irradiation.