Development of metal-organic framework (MOF) decorated graphene oxide/MgAl-layered double hydroxide coating via microstructural optimization for anti-corrosion micro-arc oxidation coatings of magnesium alloy

An efficient and simple in-situ growth strategy has been discovered for the preparation of highly reproducible and continuous symbiotic ZIF-8-based anticorrosion coating by using graphene oxide (GO)/MgAl-NO3 layered double hydroxides (G/LDHs) buffer layer as a new type of connecting carrier based on micro-arc oxide (MAO) coating of AZ31 magnesium alloy. The components of ZIF-8 were adsorbed and bounded to the surface of the G/LDHs buffer layer-modified substrates to promote the nucleation of ZIF-8, thus growing a phase-pure, uniform, and good symbiosis ZIF-8 membrane. ZIF-8 particles with different growth times compensate for the grain boundary defects of the G/LDHs coating precursor buffer layer to different degrees. The prepared ZIF-8-based coating has excellent stability and corrosion resistance. The results demonstrate that the G/LDHs buffer layer provides a new channel for the MOF-modified MAO substrate of AZ31 magnesium alloy. It also proves that it is feasible to build high-performance anticorrosive coatings with MOF materials.