Magnetically recoverable MoS2/Fe2O3/graphene oxide ternary Z-scheme heterostructure photocatalyst for wastewater contaminant removal: Mechanism and performance

Water pollution caused by organic contaminants poses a severe threat to human health and ecosystems due to their high toxicity and stability. Herein, MoS 2 /Fe 2 O 3 /GO (MFG) heterojunction composites were synthesized through ball milling and ultrasonication and used for the degradation of dye from wastewater. The as-synthesized optimal MFG composite with an optimal ratio of 2:1:1 exhibited remarkable photocatalytic activity towards Methylene Blue degradation, achieving a 97.90 % degradation in 3 hours under solar simulated irradiation and 88.2 % degradation under natural sunlight, compared to its individual components. Characterization of the composite photocatalyst revealed unique Fe 2 O 3 decoration on the MoS 2 and GO matrix, forming an intimate interface heterojunction. This structural arrangement facilitated efficient charge carrier separation, extended the visible light absorption and subsequently improved the photocatalyst’s dye degradation and redox capabilities. The experimental data showed that the photodegradation process followed pseudo-first-order kinetics at 22˚C. Quenching experiments were conducted to elucidate in detail the probable photocatalytic mechanism, which was identified as the Z-scheme mechanism. The reusability experiments showed that the photocatalyst exhibited excellent stability and reusability, maintaining a degradation efficiency of 94.32 % after four successive cycles. Overall, this research demonstrates a facile pathway to synthesize a highly efficient, stable, and easily recoverable, magnetic photocatalyst, addressing the critical issue of textile wastewater pollution. • Facile synthesis of a magnetic MoS 2 /Fe 2 O 3 /GO nanocomposite via ball-milling and ultrasonication. • The photocatalyst achieved a high degradation efficiency of 97.90 % under simulated solar light. • Reaction mechanism pathway was explored. • The photocatalyst showed high activity after four successive cycles.