SURFACTANT-ASSISTED IMMOBILIZATION OF TiO2 ONTO GLASS SUBSTRATES FOR PHOTOCATALYTIC DEGRADATION OF METHYLENE BLUE

Abstract

Titanium dioxide-based photocatalysis is a type of advanced oxidation process that can be used to completely degrade and mineralize organic pollutants. The semiconductor titanium dioxide (TiO₂) is used as a photocatalyst and is activated when it absorbs photon energy equal or greater than its band gap energy. The activation of TiO₂ as a photocatalyst leads to the formation of active sites on its surface that can trigger series of oxidative-reductive reactions to mineralize the pollutants. In most cases, TiO₂ is commonly used in slurry form and the recovery of the catalyst after water treatment often requires another separate process. To address this concern, TiO₂ photocatalyst have been immobilized on the surface of soda borosilicate glass slides with the aid of a commercial non-ionic surfactant, under the trade name Triton X-100. The TiO₂ thin film was prepared using sol-gel process and immobilized on the glass surface at different number of coatings using the dip coating technique. The TiO₂ thin films were characterized using FE-SEM, XRD and TGA and its photocatalytic activities were tested in the degradation of a model organic pollutant, methylene blue (MB). Characterization of the prepared samples by XRD showed that TiO₂ in the form of anatase was successfully deposited on the glass slides. The addition of surfactant created thicker TiO₂ thin films that showed better performance during photocatalytic activity test. The result of the activity tests showed that the TiO₂ on the glass slide was able to degrade MB and the number of times that TiO₂ was coated on the glass slide also affected the rate of MB degradation.