Synthesis of a high-performance Z-scheme 2D/2D WO₃@CoFe-LDH nanocomposite for the synchronic degradation of the mixture azo dyes by sonocatalytic ozonation process

Herein, a Z-scheme 2D/2D WO₃@CoFe-LDH nanocomposite was synthesized and characterized by XRD, FT-IR, SEM, TEM, EDX, X-ray dot mapping, BET, PL, DRS, and XPS analysis. The integration of the so-synthesized WO₃@CoFe-LDH nanocomposite, ultrasonic, and ozone inferred the existence of a synergy factor of 2.26 > 1 and 2.17 > 1 for the removal of Acid blue 9 and Acid Orange 7, respectively. Catalyst dosage of 1 g/L, the solution pH of 8, the mixture dye concentration of 50 mg/L, and the ozone flow rate of 3 L/h were determined to be the optimum value for the extreme degradation of the dye mixtures under 100 min of the sonocatalytic ozonation process. Additionally, the reusability experiments showed that the DE was above 80% after 5 times reuse of WO₃@CoFe-LDH nanocomposite implying its retained properties during the sonocatalytic ozonation process. The contributed active radicals in the degradation of the dye mixtures were profoundly studied and reported to be mainly ^•OH and O₂^•−. The so-generated intermediates were recognized using GCMS analysis and a postulated degradation mechanism was reported for each of the target pollutants in the presence of WO₃@CoFe-LDH nanocomposite. The toxicity tests proved a nontoxic media after the sonocatalytic ozonation of the mixture dyes due to the successive attack of the reactive oxygen species to the intermediates.