Porous Ceramic Foam Loading Titanium Dioxide for Photocatalytic Degradation of the Methyl Orange Solution.

Photocatalysis of titanium dioxide (Ti^O₂) has been found. High effective surface area of porous ceramic is ideal to be a catalyst support. Photocatalytic efficiency can be increased by loading Ti^O₂ film on the open-cell porous ceramic. Sol-gel method is applied in this paper. By pull Ti^O₂-soaked support to form film, a sort of lightweight open-cell reticular porous ceramic loaded with Ti^O₂ with the bulk density of 0.3~0.6 g/cm3 is produced. The ceramic is a new type of lightweight porous catalyst system. Photocatalysis of methyl orange (MO) solution under various conditions is studied in this paper. Ti^O₂-loaded samples with mass 1.0g are put into MO solution with concentration 20 mg/L and volume 50 mL, the samples are irradiated 30 min by ultraviolet (UV) lamp (500W) of wavelength 365 nm. The measured degradation efficiencies reached above 95% in general. The degradation efficiency reached 99.56% for the best sample. In this experiment, the degradation of MO is complete, and the corresponding absorption peaks disappear completely in the UV-vis absorption spectrum. Under the above experimental condition, photocatalytic efficiency rule of MO is found at different pH (3~10). The degradation efficiency is high under acid condition. The degradation efficiency decreases with an increase of pH at pH > 7. The degradation efficiency is still 94.55% at pH = 9 under the alkaline condition. The Ti^O₂ film supported on porous ceramic is found to have high degradation efficiency for MO solution at wide range of pH. [ABSTRACT FROM AUTHOR]