Utilization of stable and efficient perovskite La(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3-δ catalyst with high-entropy to boost peroxymonosulfate activation towards organics degradation

A new heterogeneous metal catalyst with greater catalytic activity and stability for peroxymonosulfate (PMS) activation is desirable to be explored. Recently, ABO3-type perovskites have attracted much attention in PMS activation, but there is still much space for improvement as its easy tailoring of composition and structure. Lately, a high-entropy perovskite showed an excellent redox and stability, being a promising material in the field of electrochemistry. Herein, a high-entropy perovskite La(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3-δ, termed LCMFCN, was synthesized and first applied to activate PMS for organics degradation. In the presence of 0.05 g·L−1 LCMFCN and 1 mmol·L−1 PMS, 99.1 ± 0.6% of Rhodamine B (RhB, 10 mg·L−1) was degraded within 60 min, which outperformed most perovskites with a single cation at the B-site (e.g., LaNiO3). The LCMFCN also exhibited excellent stability, with RhB degradation efficiency of ∼96% after five consecutive cycles. 1O2 was suggested to play a vital role in RhB degradation in the PMS/LCMFCN system and two pathways of 1O2 generation were proposed: (i) 1O2 could evolve from the lattice oxygen, and (ii) 1O2 converted from O2•−. The results of this study suggest that the high-entropy perovskite can efficiently activate PMS for organics degradation, expanding the design range of perovskites application in water treatment.