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

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.

Design and Synthesis of Mosaic ZnO/g-C3N4 Heterojunction Materials with Excellent Anticorrosion Performance

“…As seen in Figure S2­(a–f), the R p values of the pure epoxy resin coating, ZnO, CN, ZCN1, ZCN2, and ZCN3 coatings are 1780.4, 2197.6, 2989.9, 6282.4, 7592.9, and 5023.9 Ω · cm 2 , respectively, which presenting the same pattern as the impedance plots. The R p value of the ZCN2 coating is 2.3 times that of the pure epoxy resin coating, showing that the addition of ZCN2 heterojunction material makes the electrons generated by the oxidation reaction of the iron matrix flow between the coatings with the greatest resistance, which reduces the corrosion rate of the iron matrix significantly …”

“…The R p value of the ZCN2 coating is 2.3 times that of the pure epoxy resin coating, showing that the addition of ZCN2 heterojunction material makes the electrons generated by the oxidation reaction of the iron matrix flow between the coatings with the greatest resistance, which reduces the corrosion rate of the iron matrix significantly. 31 3.4. Anticorrosion Mechanism.…”