Rationally designed ternary TiO2/ZnO/SrFe2O4 heterojunction photocatalyst towards efficient visible-light-induced degradation of binary mixture of basic yellow 28 and basic blue 41 dyes

The design and fabrication of hybrid nanostructures featuring enhanced photocatalytic properties have long been of interest to scientists in attempts to eliminate environmental pollution, particularly those emanating from degraded dyes of industrial wastewater. However, research has often strived to remove dyes in single solutions, while there are a few reports to remove them in binary mixture. This research assesses a ternary TiO₂/ZnO/SrFe₂O₄ nanocomposite for its visible-light-driven photocatalytic activity in degrading basic blue 41 (BB41) and basic yellow 28 (BY28) dyes in the single and binary systems. ZnO and SrFe₂O₄ nanoparticles (NPs) synthesized via the sol-gel method were loaded onto the surface of TiO₂ nanorods to form a heterojunction composite. The degradation efficiency was optimized by adjusting initial dye concentration, catalyst dosage, initial pH, and duration of irradiation as key process parameters. Optimally (20 mg/L initial dye concentration; 0.5 mg/L catalyst dosage; and pH: 6.5), the degradation rate of BY28 and BB41 dyes was 0.0423 and 0.0405 min⁻¹ in the single solutions and 0.0388 and 0.0348 min⁻¹ in their respective binary solutions, respectively.