Method for attachment of TiO2 using design of experiments: application to the photocatalysis of a model pollutant methylene blue dye.

Abstract

The preparation of titanium dioxide (TiO2) supported on a glass plate by heat attachment method is presented. With the use of response surface methodology based on a central composite design we investigated the influence of the experiment parameters of the TiO2 deposition (temperature of calcination (T), time of calcination (ts) and the concentration of TiO2 ((TiO2))) on photocatalytic activity of the semiconductor for the degradation of a model pollutant: methylene blue. The analysis of variance results showed that the selected quadratic model with interaction (R2 = 0.9802) was statistically significant. The experimental results showed that the degradation quantity of methylene blue increased when the ts value increased and T decreased. We have evaluated the photocatalytic activity of this supported catalyst (TiO2-GP) with a laboratory reactor under natural condition; the maximum removal (96.03%) was obtained at ts = 331 min, T = 559 °C and (TiO2) = 2.38 g/l. The method of desirability function was used to obtain the best combination of factor settings for achieving the maximum of degradation quantity ((TiO2) = 2.6 (g/l), T = 600 (°C) and ts = 240 (min)). The additional tests on the catalyst plates confirmed that the deposits keep their catalytic activity for several cycles of use.