Enhanced Visible-Light Photocatalytic Activity of TiO2 via LaFeO3 Perovskite Modification

In this work, TiO2/LaFeO3 nanocomposites with varying lanthanum ferrite content were synthesized and comprehensively characterized to enhance the efficiency of photocatalytic processes under solar irradiation. The structural, morphological, and textural properties of the samples were investigated by SEM, TEM, HRTEM, XPS, Raman spectroscopy, and BET analysis. The incorporation of LaFeO3 was found to extend the light absorption range of TiO2 into the visible region and to modify the surface textural characteristics while preserving the mesoporous structure of the composites. Photoelectrochemical measurements and electrochemical impedance spectroscopy revealed that the formation of a p–n heterojunction between n-TiO2 and p-LaFeO3 promotes more efficient separation of photogenerated charge carriers and significantly reduces the charge-transfer resistance. The best performance was achieved for the TLFO_2.0 sample, which exhibited the highest photocurrent density (51.85 μA/cm2) and the highest photocatalytic activity toward the degradation of MB, RhB, and CR. After 240 min of irradiation, the degradation efficiencies reached 57.3% for MB, 90% for RhB, and 33.8% for CR. These results demonstrate that optimizing the LaFeO3 content is an effective strategy for enhancing the photoelectrochemical and photocatalytic performance of TiO2/LaFeO3 nanocomposites, highlighting their promise for applications in wastewater treatment and solar energy conversion systems.