Characterization of TiO2-coated ceramic foam prepared by modified sol-gel method and optimization of synthesis parameters in photodegradation of Acid Red 73

Abstract

TiO2 nanoparticles were synthesized by the P-25 powder modified sol-gel method under different TTIP (Titanium tetraisopropoxide) concentrations, P-25 loading and the gelation pHs. Structural properties of nanoparticles were characterized by XRD, FESEM and BET analysis. Results show that crystallinity level, particle size and the surface area are a function of P-25 loading and gelation pH, whereas TTIP concentration affects only the crystalline composition. Response surface methodology based on central composite design was used to optimize these synthesis parameters in photodegradation of Acid Red 73. The degradation efficiency was significantly affected by P-25 loading, pH value of gelation and the interaction effect between TTIP concentration and P-25 loading. The optimal values of parameters were found to be a pH of 1.34, a TTIP concentration of 0.25M and a P-25 loading of 39.76 g/L. At optimal synthesis conditions, TiO2 film was coated on alumina foam and its structural properties were characterized by XRD, SEM and BET technique. The photocatalytic activity of the as-prepared films was found to be higher than that of the films prepared by the sol-gel method and those made from the slurries of P-25. The reasonable photocatalytic performance and good stability offered by the optimized film make it as an effective alternative for large application of water treatment.