Enhanced removal of organic dye by activated carbon decorated TiO₂ nanoparticles from Mentha Aquatica leaves via ultrasonic approach

The development and investigation of environmental-friendly photocatalysts remain a challenge for eco-system remediation concerns. Herein, an ultrasonically-driven, biogenic, green synthesis of titanium dioxide (TiO₂) nanoparticles (NPs) utilizing the extract of Mentha Aquatica leaves is reported. The TiO₂ nanoparticles were further functionalized with carbon (TiO₂@Carbon). The product composition and structure were examined through Raman, BET, and XPS analysis. The XRD studies of the TiO₂ NPs confirmed the anatase phase of nanostructures. The TiO₂@Carbon NPs displayed enhanced photocatalytic activity(doubled) compared to pristine TiO₂ due to their increased surface area, a bathochromic shift in the optical absorption band, and effective charge separation. Significantly, greater than 90% RhB dye was decayed during the photocatalytic oxidation method, which is validated via trapping active species experiment. Carbon is a powerful substrate for the TiO₂ hybrid and can be reused over successive five catalytic cycles. The experimental results demonstrated the TiO₂@Carbon as a potential candidate for highly-efficient, eco-friendly, reusable, cost-effective photocatalyst.