TiO₂-functionalized mesoporous silica thin films synthesized by spin-coating to enhance methylene blue and methyl orange removal efficiency

The textile industry as one of the largest industries in the world has been the biggest contributor to global water pollution in recent decades. Azo dyes such as methylene blue (MB) and methyl orange (MO) contained in the textile effluent can be a serious threat to aquatic ecosystem and human health. Thus, an effort to create an effective dye removal is needed. This study studies the application of dye removal by combining adsorption and photodegradation methods through the use of mesoporous silica/TiO₂ thin film fabricated by spin coating. The resulting TiO₂ has anatase phase as confirmed by the XRD result, while mesoporous silica has good surface and pore properties, as evidenced by a surface area of 1291.42 m²/g, a pore volume of 1.91 mL/g, and a pore diameter of 3.07 nm. After exposuring to the 10 ppm MB and MO solutions for four hours at a pH of 7, the synthesized mesoporous silica/TiO₂ thin film exhibited the best removal performance compared to the mesoporous silica thin film and TiO₂ thin film, with removal percentages of 77.90 % and 17.19 % for MB and MO, respectively. The difference in removal performance between MB and MO occurs due to the selective nature of mesoporous silica and TiO₂ caused by different interaction mechanisms.