Development of ferrimagnetic (Mn0.6Cr0.6Co0.6Fe0.6Al0.6)O4 high entropy oxide for photo-Fenton degradation of organic dye

Abstract

Herein, we report the development of nanosized MHEO composed of Mn, Cr, Co, Fe, and Al, (Mn0.6 Cr0.6 Co0.6 Fe0.6 Al0.6)O4 through sol–gel method, followed by calcination at high temperature. X-ray diffraction pattern (XRD) and transmission electron microscopy (TEM) analyses confirmed the successful formation of single-phase nanosized HEO, while X-ray photoelectron spectroscopy (XPS) analysis revealed the oxidation states of the individual elements present in it. This inverse spinel-structured oxide exhibited soft ferrimagnetic behavior, despite the fact that the individual oxides are either ferrimagnetic, paramagnetic or antiferromagnetic at room temperature. It exhibited excellent photo-Fenton catalytic degradation of organic dye, methylene blue (MB) and its complete degradation was achieved in 90 min. The successful degradation and mineralization of MB through photo-Fenton process were evident from mass spectroscopic analysis. The observed high MB degradation activity can be attributed to the generation of electron-hole pair under UV light as well as to the contribution of all constituent metal ions except Al3+ in providing additional active redox sites for Fenton degradation. The magnetic property of the developed MHEO provided an added advantage, making it easier to recover after recycling studies. © 2025 Elsevier B.V.