Optimization of enhanced UV photodegradation of Malachite Green using sediment@TiO2 composite

This research paper investigates the photodegradation of Malachite Green (MG) using a new composite of river sediment (Sd) and synthesized TiO₂ (Sd-TiO₂-X%). TiO₂ powder was synthesized using the sol–gel method and catalyst composites Sd-TiO₂-X% (X = 10%, 15%, and 20%) were obtained using the wet impregnation. The photocatalytic performance of the composites was investigated using Box–Behnken design and results in the optimal parameters of %TiO₂ (%) = 19.73, [MG] (ppm) = 42.25, and pH 9.58. Furthermore, Sd-TiO₂-20% demonstrated exceptional stability and performance after undergoing five cycles. The scavenging tests for free radicals strongly confirmed the activity of superoxide ions (O₂^⋅−) and hydroxyl radicals (^⋅OH) as the primary species responsible for degrading MG. The findings highlight the synergetic effect between river sediment and TiO₂ in the photodegradation of organic pollutants-contaminated wastewater. This confirms the potential of valorizing sediments for promising and sustainable depollution applications using sediment-based materials.