Two-component transparent TiO2/SiO2 and TiO2/PDMS films as efficient photocatalysts for environmental cleaning

Optimized deposition of TiO2 thin films produced by a non-aqueous sol–gel method and quantification of their photocatalytic activity

“…In the cases where the initial dye concentration is a millimolar solution, the L-H equation can be simplified to an apparent first-order equation [24]. Several examples of dye degradation using TiO 2 powders as catalyst and adhering to this process have been reported [9,11,25,26]. In those studies, it has been shown that the dye interacts strongly with the catalyst and then, the time required to reach the adsorption equilibrium is relatively long.…”

“…The photocatalytic activity of each TiO 2 thin film was evaluated by following the degradation of methylene blue (MB) which was used as a model molecule to represent a pollutant [11,23]. The films were placed at the bottom of a plastic Petri dish and immersed in a solution of MB (2 × 10 -5 mol L -1 ) and the dishes were closed with a plastic lid in order to avoid evaporation.…”

“…Each coating was covered with a piece of scotch tape and the adherence was considered adequate if the removal of the tape did not cause visible damages to the coating [11].…”

“…In the last decade, the photocatalytic degradation of methylene blue under artificial UV light in the presence of TiO 2 based catalyst has been widely used as a reference test to assess the photocatalytic activity of a catalyst [11,23]. It is generally admitted that a LangmuirHinshelwood (L-H) expression can be used to describe the photocatalytic discoloration of dye.…”

“…In recent decades, the sol-gel method has become an interesting approach for the synthesis of TiO 2 bulk [6][7][8][9], thin films [10,11] or hybrid membrane [12]. Homogeneous and highly pure thin films with controlled thickness, composition and microstructure can be prepared by different processes such as dip-coating, spin-coating or spray-coating from a liquid sol-gel solution.…”