LAUSR

Abstract ABO3-type perovskite oxides with abounding defect structures and diverse physical chemistry attributes have been extensively studied in heterogeneous catalysis. Semiconductor LaFeO3 perovskites fabricated via the sol–gel method were used as peroxydisulfate (PDS) activators for methylene blue (MB) degradation under low-intensity ultra-violet (UV)-light to evaluate the degradation efficiency of organic pollutants and mechanism. The results indicate that under low-intensity UV irradiation, the developed UV/LaFeO3/PDS system shows excellent degradation ability of organic pollutants in a wide pH range. Electron spin resonance and radical quenching experiments verify that SO4·−, •OH, h+ and 1O2 are generated during the activation process, and 1O2 plays a dominant role in MB degradation. Reduction of low oxidation state Fe(II) and O22−/O− on the LaFeO3 surface shows that oxygen vacancy, as the electron transfer mediator, enhances the redox cycle efficiency of Fe(II)/Fe(III). Photogenerated electrons of LaFeO3 involve in the cyclic transformation of Fe(II)/Fe(III) and PDS activation further increase the number of active radicals and thus promote the synergistic effect of photocatalytic coupled with sulfate radical-based advanced oxidation processes.