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

Abstract

BackgroundA 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. Method & resultHerein, 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•−. IndicateThe 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.