Development of CeO₂/Fe₂O₃ nanocomposite for photocatalytic and biological studies

A CeO₂/Fe₂O₃ heterojunction nanocomposite was synthesized via a solution combustion route to engineer enhanced photo-induced reactive oxygen species (ROS) generation for environmental and biological applications. Structural and spectroscopic analyses confirmed the formation of a well-integrated heterostructure with reduced crystallite size (∼15.78 nm), narrowed band gap (2.81 eV), and increased oxygen-vacancy concentration. Photoluminescence quenching and XPS results demonstrated improved interfacial charge separation and redox-active Ce³⁺/Ce⁴⁺-Fe³⁺ coupling. Under UV irradiation, the composite achieved 89.93% degradation of Brilliant Cresyl Blue (BCB) dye within 60 min (k = 0.04241 min^-1), outperforming individual oxides due to enhanced ROS production. Scavenger and LC-MS analyses confirmed that •O₂^-, •OH, and h⁺ species were responsible for efficient dye mineralization. Importantly, the elevated ROS generation also translated into pronounced antimicrobial and DNA-damaging effects, demonstrating a direct correlation between heterojunction-mediated charge dynamics and biological activity. These findings highlight the CeO₂/Fe₂O₃ system as a rationally engineered photochemical platform for integrated wastewater remediation and ROS-based antimicrobial applications.