Enhanced Fenton-like degradation of refractory organic compounds by surface complex formation of LaFeO3 and H2O2

Nanoscale LaFeO3 was prepared via sol-gel method and characterized by XRD, FTIR and N-2 adsorption/desorption experiment. The results indicated that, LaFeO3 had a typical perovskite structure with a BET area of 8.5 m(2)/g. LaFeO3 exhibited excellent Fenton activity and stability for the degradation of pharmaceuticals and herbicides in water, as demonstrated with sulfamethoxazole, phenazone, phenytoin, acyclovir and 2,4-dichlorophenoxyacetic acid, 2-chlorophenol. Among them, sulfamethoxazole (SMX) could be completely removed in LaFeO3-H2O2 system after reaction for 120 mm at neutral pH. Based on the ATR-FTIR analysis, the surface complex of LaFeO3 and H2O2 was formed, which was important and essential for the enhanced Fenton reaction by accelerating the cycle of Fe3+/Fe2+. Hence, more (OH)-O-center dot and O2(center dot-)/HO2 center dot- were then produced in LaFeO3-H2O2 system, resulting in more efficient removal of refractory organic compounds. Based on the surface interaction of LaFeO3 and H2O2, a heterogeneous Fenton reaction mechanism was proposed. (C) 2015 Elsevier B.V. All rights reserved.