Ti-substituted LaFeO3 perovskite as photoassisted CWPO catalyst for water treatment

New Ti-substituted LaFeO3 perovskites have been synthesized via a sol-gel method with partial substitution of La by Ti and used as catalyst in the photoassisted CWPO for the removal of 4-Cl-Phenol in water. The influence of the calcination temperature and the Ti at.% content was evaluated in terms of activity and stability. The Ti-substituted LaFeO3 catalyst calcined at 800 °C showed an activity optimum for a 3.2 at.% content of Ti in the presence of the stoichiometric dose of H2O2, with a higher mineralization rate and yield than its LaFeO3 counterpart, while achieving complete Cl-phenol removal and 100% mineralization at circumneutral pH, ambient pressure and temperature. The La partial substitution by Ti and the increase in the calcination temperature strongly improved the catalyst stability in terms of Fe leaching, and the Ti-substituted LaFeO3 catalyst calcined at 800 °C displayed stable performances over 5 cycles of reaction, with a limited Fe leaching lower than 0.1% of its total content. The catalyst was active simultaneously in both photoassisted CWPO and photocatalysis under UV-A light. Thus, the photoassisted CWPO with Ti-substituted LaFeO3 catalysts may overcome some drawbacks of single AOPs by combining higher rates at complete mineralization.