Assessment of ionic site distributions in magnetic high entropy oxide of (Mn0·2Fe0·2Co0·2Ni0·2Zr0.2)3O4 and its catalytic behaviour

Abstract

Herein, we report a single phase equi-atiomic high-entropy oxide (HEO) of a new composition (Mn0·2Fe0·2Co0·2Ni0·2Zr0.2)3O4 with spinel structure. The material was synthesized via microwave energy irradiated co-precipitation technique and a subsequent calcination at 500 °C. The X-ray diffraction and selected area electron diffraction assisted in the crystal phase determination. While the STEM-EDS elemental mapping was used to realize the chemical homogeneity and elemental distribution. The synchrotron X-ray absorption spectroscopy aided to determine the ionic states of constituents and their distribution over the octahedral (Oh) and tetrahedral (Td) co-ordination environment. It displayed ferrimagnetic nature with a magnetization of ∼12 emu/g at an applied field of 90 kOe. Intriguingly, the synthesized material performed well as a catalyst in the Fenton degradation of Tetracycline micropollutant. The degradation behaviour followed a zero-order kinetic and the rate constant is calculated as 0.43 mol L−1s-1. © 2023 Elsevier B.V.