Improved catalytic activity in peroxymonosulfate activation over manganese-based perovskite oxides with acid treatment

Increasing attention has been paid to the perovskite oxides activating peroxymonosulfate (PMS) for wastewater treatment. In this article, the La0.65Sr0.35MnO3 (LSMO) treated with dilute HNO3 was explored for PMS activation. The La0.65Sr0.35MnO3/Mn3O4 composite is obtained after acid etching. The valence state of B-site Mn and surface oxygen vacancies are populated by etching different time. The LSMO-3 h (etching for 3 h) exhibits the best catalytic performance due to the activation of lattice oxygen, which induces improved redox ability. Minimal reactive oxygen species (ROS) such as OH, SO4−, 1O2, and O2− are generated, contributing little to bisphenol A (BPA) degradation. The Mn(III)-PMS complex and highly oxidative Mn(IV) under the acidic environment are responsible for the excellent degradation. The findings demonstrate an effective strategy of surface etching in enhancing the catalytic performance of perovskite oxides for advanced oxidation.