Synthesis and Mechanism of Co2+/Sr2+ Codoped Magnetic Lanthanum Cuprate with Excellent Corrosion Resistance

ACS Appl Mater Interfaces. 2023 Nov 22;15(46):53651-53664. doi: 10.1021/acsami.3c09858. Epub 2023 Nov 9.

Abstract

The special structure of perovskite-like compounds allows the existence of some open spaces in the crystals that play an important role in their crystal function enhancement and can accommodate active oxygen, which helps to solve some problems in the field of corrosion prevention. The magnetic lanthanum cuprate was obtained through the doping of Co2+ and Sr2+, and compared with La2CuO4 and epoxy resin, its corrosion resistance was improved by 215.2 and 566.7%, respectively. The micromagnetic field in the crystal interfered with the state of motion of the electrons and prolonged their transport path. High concentration doping and substitution of unequal states led to the formation of oxygen vacancy defects, which could trap active oxygen molecules and inhibit cathodic corrosion reactions. The unique alternating interlayer structure of perovskite-like compounds was conducive to the release of Cu2+, thus forming a more stable passivator on the surface of the coating. La1.96Sr0.04Cu0.98Co0.02O4 had both magnetic properties and structural advantages, which enhanced the shielding property of epoxy resin and expanded the application of perovskite-like compounds in the field of corrosion prevention.

Keywords: lanthanum cuprate; magnetism; perovskite-like compounds; solid solution doping; synergistic anticorrosion.