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 (O-2(<bold>& sdot;</bold>-)) and hydroxyl radicals ((OH)-O-<bold>& sdot;</bold>) 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.