This study aims to synthesize a low-cost TiO₂/Fe₂O₃ heterostructure using the spray pyrolysis technique at different deposition temperatures and to evaluate its photoelectrocatalytic performance for methylene blue (MB) degradation as a model dye pollutant in water. X-ray diffraction confirmed the presence of rhombohedral Fe₂O₃ and tetragonal TiO₂ as well as the impurity-free coexistence of both phases in the TiO₂/Fe₂O₃ composite. Optical characterization revealed that the heterostructure exhibits a reduced band gap of 2.1 eV compared to 3.4 eV for TiO₂ and 2.8 eV for Fe₂O₃ indicating improved absorption in the visible light region. Scanning electron microscopy showed a porous, compact and interconnected cauliflower-like morphology composed of nanograins. The binder free composite is phase pure and exhibits a reduced band gap of 2.1 eV enabling strong visible-light absorption. Under visible-light illumination the TiO₂/Fe₂O₃ heterojunction achieves 72.45% degradation of methylene blue compared to 59.87% achieved by pure TiO₂ under UV light demonstrating significantly improved photocatalytic activity. This enhancement is attributed to efficient interface driven charge separation and increased generation of reactive oxygen species. These findings suggest that spray-deposited TiO₂/Fe₂O₃ heterostructures are efficient low-cost photoelectrocatalysts with strong potential for water purification applications. This mechanistic interpretation is consistent with previously reported TiO₂/Fe₂O₃ systems where improved performance is generally attributed to enhanced visible light absorption more effective charge separation and reactive oxygen species mediated oxidation.
Waghmode et al. (Mon,) studied this question.