Comparative study of ZnO-TiO2 nanocomposites synthesized by ultrasound and conventional methods for the degradation of methylene blue dye

Abstract

ZnO-TiO₂ nanocomposites (ZTN) have been synthesized using both ultrasound-assisted and conventional methods. The characterization techniques like XRD, FTIR, BET, FESEM, EDS, and UV-visible confirmed that the ZTN is successfully formed. The photocatalytic activity and kinetics of the ZTN are assessed using methylene blue (MB) dye as a pollutant. Various factors such as synthesis processes, catalyst loading, initial dye concentration, temperature, and pH have been investigated to determine their impact on dye degradation. The ZTN synthesized with ultrasound exhibited superior photocatalytic activity compared to the conventionally synthesized ZTN. The highest dye degradation (97.69%) was observed under the optimum conditions of 1 g/L photocatalyst dosage, 20 ppm dye concentration, pH 10, and a temperature of 55℃. Additionally, the kinetic study revealed that the degradation of the dye by ZTN followed a second-order kinetic model.