Removal of Methylene Blue Dye from Aqueous Solution Using a Newly Synthesized TiO2-SiO2 Photocatalyst in the Presence of Active Chlorine Species

Abstract

Industrialization and urbanization demand high amount of water consumption, which contributes to their polluted condition. Thus, there is a need to develop a sustainable wastewater remediation technique in order to provide sustainable use of clean water for future generations without ramifications to the economic sectors. The newly synthesized TiO2-SiO2 photocatalyst was used to remediate Methylene Blue contaminated aqueous solution in the presence of active chlorine species. The doping of SiO2 into TiO2 enhanced the removal rate of Methylene Blue dye from the solution by increasing the surface area, thermal stability and surface acidity of the TiO2. The active chlorine species further enhanced the removal rate of Methylene Blue dye from the solution by contributing more reactive species, chlorine radicals, which broke down the dye molecules. The experiments were conducted via Taguchi analysis. The findings show that combining TiO2, SiO2 and active chlorine species enhanced the removal percentage of Methylene Blue dye compared to using TiO2 alone by 70%. About 70% of 50ppm Methylene Blue was degraded by 1 g of TiO2-SiO2 in the presence of 0.3 ppm Ca(OCl)2 under 9 Watts solar irradiation within 3 hours. The enhanced dye removal method brings photocatalysis a step closer to sustainable wastewater remediation methods.