Fabrication of TiO2–ZrO2 coating on continuously porous SiC–Si3N4 composites

Continuously porous SiC–Si3N4 composite using waste SiC sludge was fabricated by extrusion process. They were comprised with SiC, β-Si3N4 and a small amount of Fe phase. But inside the continuously pore surface many Si3N4 whiskers were clearly observed. To make a TiO2–ZrO2 coating on the composite, the dip coating process was adapted, using synthesized nano TiO2–ZrO2 composite powders. TiO2–ZrO2 particles were coated on the pore wall of the composite as well as on the matrix. TiO2 and ZrO2 particles existed with anatase and tetragonal phases, respectively, after calcination at 600 °C. TiO2–ZrO2 coated continuously porous SiC–Si3N4 composites showed promising effect in photocatalytically degrading phenol in the solution.