Photocatalytic degradation of ternary dye mixture in aqueous environment using gold nanoparticles loaded amino and mercapto functionalized TiMCM-41 nanocatalysts in the presence of visible light

Gold nanoparticles loaded thiol and amino functionalized nanocatalysts (Au-SH-TiMCM-41 and Au-NH₂-TiMCM-41) were successfully synthesized by modifying the prepared pure TiMCM-41 with 3-aminopropyltriethoxysilane (APTS) and 3-mercaptopropyltriethoxysilane (MPTS) followed by gold loading. The nanocatalysts were characterized with various analytical methods in order to understand the morphologies. Further, a ternary dye effluent containing a mixture of three azo dyes, namely methyl orange, acid red 88 and acid orange 10, used in dyeing of cotton fabric was prepared. The photocatalytic degradation of the dye mixture was carried out with synthesized hybrid nanocatalysts in the presence and absence of peroxomonosulphate (PMS). The photocatalytic degradation experiments indicated that there are some practical difficulties in degrading these organic contaminants due to the presence foreign substances added during the dyeing process, which decreased the production of non-selective powerful oxidizing radicals.