Chelating adsorption-engaged anionic dye removal and Fenton-driven regeneration in ferromagnetic Ti/Co-LaFeO3 perovskite

Creating adsorbents that exhibit high selectivity towards pollutants, can be readily regenerated, and maintain high stability, remains a crucial challenge in water treatment technology. Herein, we present a magnetically and chemically recoverable absorbent based on Ti and Co co-substituted LaFeO3 (La0.9Fe0.55Ti0.3Co0.15O3, LFTCO) with significantly enhanced adsorption properties. Notably, LFTCO exhibits a methyl blue adsorption capacity (qmax) of 2131 mg/g, setting a new record among perovskite oxides, due to the increased surface oxygen vacancy with the dual doping strategy. The selected dual-dopant consists of Fenton active Co and spin-state interactive Ti, which allows creating more oxygen vacancy and simultaneously facilitating pragmatic regeneration of the adsorbent. The new LFTCO exhibits significantly enhanced ferromagnetism (M = 7.27 emu/g), enabling rapid magnetic separation from water and subsequent Fenton-based regeneration step. We also reveal that the anchored configuration of SO3-defect site, through density functional theory (DFT) calculation, as the most favorable site for the adsorption process. These findings provide a pathway to creating high-performance adsorbents and shed light on the mechanistic understanding of LFTCO's enhanced adsorption properties.