<p>This study investigates the synthesis and photocatalytic performance of TiO₂/Fe₂O₃ heterostructures with varying Fe₂O₃ content for water purification applications. Titanium dioxide (TiO₂) nanoparticles were synthesized using the sol–gel method, while iron oxide (Fe₂O₃) nanoparticles were prepared via solid-state chemical reaction. Five different TiO₂/Fe₂O₃ heterostructures were synthesized by varying the content of Fe₂O₃. The structural characteristics of the prepared samples were analyzed using x-ray diffraction (XRD), which confirmed the formation of anatase TiO₂ and hematite Fe₂O₃ phases. The particle size was found to range from 26.52&#xa0;nm to 33.14&#xa0;nm for TiO₂ and 20.76&#xa0;nm to 29.35&#xa0;nm for Fe₂O₃. The enhanced crystallinity and phase purity observed in sample 5, with a ratio of TiO₂:Fe₂O₃ of 1:0.25, imply that the Fe₂O₃ domains are more effectively integrated into the heterostructure, forming a stable and efficient interface with TiO₂. The morphology of the samples, observed via scanning electron microscopy (SEM), showed uniform, well-structured grains, with a noticeable difference in grain size with varying Fe₂O₃ concentrations. Fourier transform infrared spectroscopy (FTIR) highlighted the presence of hydroxyl groups and carbonate bonds in the TiO₂/Fe₂O₃ heterostructures. Simulations using density functional theory (DFT) predicted that the TiO₂:Fe₂O₃ (1:0.25) sample exhibited the highest photocatalytic efficiency, with an absorption value of approximately 3.2 × 10⁵ at an energy value of 3.2&#xa0;eV, as well as maximum optical conductivity of 5.7 Scm⁻¹ in the real part. Additionally, the material exhibited the lowest energy loss function, suitable for optical applications. These findings demonstrate that varying the Fe₂O₃ content in TiO₂/Fe₂O₃ heterostructures can achieve optimized photocatalytic performance for water purification, with the TiO₂:Fe₂O₃ (1:0.25) sample showing superior optical and photocatalytic properties.</p>