Preparation method and growth mechanism of high-purity iron coatings on non-metallic surfaces

In this paper, the preparation method and growth mechanism of high-purity iron coatings on non-metallic surfaces are systematically investigated. High-purity iron coatings were prepared by a two-step electroless plating method. Traditional electroless iron plating is used to metallize non-metallic surfaces, and Al-induced electroless iron plating is utilized to create high-purity coatings. The iron coatings obtained by the two kinds of electroless plating methods were characterized by field emission scanning electron microscopy, X-ray diffraction, and electrochemical analysis. Subsequently, the deposition and growth processes of iron coatings on non-metallic substrates were simulated by molecular dynamics and 3D modeling. Finally, the corrosion resistance of high-purity iron coatings was analyzed by polarization curves. The results demonstrate that the iron coatings prepared by the two-step electroless plating method are of high quality and of pure composition. The particle shapes achieved by molecular dynamics and 3D modeling exactly reproduce the spherical-like shape of the iron particles in the coating morphology. Furthermore, the formation process of iron particles and the growth mechanism of iron coatings were obtained. Through electrochemical analysis, aluminum foil as a reducing agent is able to satisfy the conditions for spontaneous reaction. Due to the decomposition of the aluminum foil, which provides the reducing electrons and decreases the surface potential, the solution compositions of Al-induced electroless iron plating are uncomplicated. Therefore, the iron coating is the only reaction product. The high-purity iron coating exhibits excellent corrosion resistance. This vastly enhances the practicality of electroless iron plating.