Synthesis of Ag₂O Coated TiO₂ Nanoparticles by Sonochemically Activated Methods for Enhanced Photocatalytic Activities

TiO₂ nanoparticles were successfully synthesized by sol-hydrothermal (SH) method using sonochemically activated precursors. Sonochemical activation yields product bearing desirable crystallinity at relatively lower temperature in comparison with conventional SH method. Glycine was used as a mineralizer in the ultrasound activation process which suppress the formation of brookite phase (of TiO₂) observed in the sonochemically activated sample. TiO₂ sample synthesized in presence of Glycine [SA-SH(GLY)] was further modified by coating Ag₂O nanoparticles by sonochemical (SD-Ag) and photochemical (PD–Ag) methods. The deposition by sonochemical method yields product with better crystallinity, high surface area and improved optical properties. Morphological investigations confirm the formation of rounded cube and cube shaped Ag₂O particles in the sonochemical and photochemical methods respectively. Photoactivities of the catalysts were investigated in terms of degradation of methyl orange (MO) dye contaminated aquatic waste. Equilibrium of MO photo-degradation was achieved within about 90 min with removal efficiencies of 99.9, 67.1, and 44.4% for SD-Ag, PD–Ag, and SA-SH-(GLY) samples, respectively at 50 mg/L of MO dye concentration. The high photo-catalytic activity of SD-Ag sample was observed for MO photo-degradation, which is attributed to the improved properties like crystallinity, visible light absorption capacity and higher surface area.

Advance route of sonochemical activation process for synthesis of Ag₂O co-capped TiO₂ nanocomplex for MO photo-degradation