New insights into the charge property at active sites boost PMS activation over LaFe0.3Mn0.7O3

Perovskite-based materials have become a new direction for peroxymonosulfate (PMS) activation in pollutants degradation. However, the mechanism towards PMS activation remains insufficient. In this paper, a series of LaM_xMn_1-xO₃ materials with B-site doping were developed by sol-gel self-propagating combustion method. The prepared LaFe_0.3Mn_0.7O₃/PMS system exhibited the desired catalytic activity, almost 100% removal efficiency of TC can be achieved within 50 min and 98% initial catalytic activity could be maintained after 5 cycles. Quenching experiments and EPR tests together certified the vital roles of •O₂^- and ¹O₂ during the TC degradation procedure. Simultaneously, the catalytic performance of the LaFe_0.3Mn_0.7O₃/PMS system was examined in relation to varying pH values, coexisting chemicals, and water conditions. DFT calculations demonstrated an increased electron concentration in the reactive sites after Fe doping. In addition, LaFe_xMn_1-xO₃ at the electron-rich state increased the bond strength with O atoms and encouraged the adsorption/desorption of intermediates in the PMS activation process. The aforementioned outcomes showed the possibility for application in intricate, realistic aquatic environments.