Magnetic Manganese‐Based Micromotors MnFe ₂ O ₄@ Fe ₃ O ₄/ graphite and Mn ₂ O ₃@ Fe ₂ O ₃@ Fe ₃ O ₄/ graphite for Organic Pollutant Degradation

Abstract

Wastewater pollution with organic compounds poses a serious threat to human health. One of the possible methods for solving these problems can be the use of micro/nanomotors. Among them, manganese‐based micro/nanomotors have a number of important advantages related to high catalytic activity, powerful motion, and low cost. Due to their mobility, micro/nanomotors promote an increase in the intensity of mass transfer in the reacting system. When introducing ferromagnetic elements into manganese‐based micro/nanomotors, it is possible not only to increase their motion speed, but also to make their motion more controllable. Herein, for the first time it demonstrates a synthesis method for MnFe ₂ O ₄@ Fe ₃ O ₄/ graphite and Mn ₂ O ₃@ Fe ₂ O ₃@ Fe ₃ O ₄/ graphite magnetic catalytic micromotors, which have remarkable photocatalytic properties. Micromotors are clusters of nanoparticles whose motion in a hydrogen peroxide solution in a non‐uniform magnetic field is caused by the action of magnetic force and self‐diffusiophoresis. Nanoparticles are synthesized by the plasma‐arc method with subsequent annealing in the air. When changing the annealing temperature, the catalytic and magnetic properties of nanoparticles can vary within a wide range of values. Micromotors MnFe ₂ O ₄@ Fe ₃ O ₄/ graphite have the most optimal catalytic and magnetic properties. The results of the research show that these micromotors are effective catalysts in the decomposition of methylene blue.