Fabrication of TiO₂/CeO₂/CeFeO₃ tandem n-n heterojunction nanocomposites for visible-light-triggered photocatalytic degradation of tetracycline and colored effluents

In this work, the TiO₂ integrated CeO₂/CeFeO₃ nanocomposites with tandem n-n heterojunctions were synthesized and utilized as visible-light-triggered photocatalysts for photodegradation of aquatic contaminants. The ternary TiO₂/CeO₂/CeFeO₃ nanocomposite with optimum composition exhibited a significant photocatalytic performance for the degradation of tetracycline, methylene blue, fuchsine, and rhodamine B with rate constants of 358 × 10⁻⁴, 416 × 10⁻⁴, 302.3 × 10⁻⁴, and 220 × 10⁻⁴ min⁻¹, which were 39.0, 22.3, 21.3, and 22.8 times higher than those of pristine TiO₂, respectively. Thanks to the created tandem n-n heterojunctions, the high electron-hole separation efficiency and facile migration of charge carriers were found as the major causes of the powerful degradation outcomes. This study establishes an inexpensive and effortless approach for synthesizing innovative series of heterogeneous photocatalysts to address the water pollution crisis.