A trace amount of MXene@PDA nanosheets for low-temperature zinc phosphating coatings with superb corrosion resistance

In this study, MXene nanosheets were functionalized by polydopamine to fabricate MXene@PDA (PMX) hybrid nanomaterial as an accelerator for low-temperature phosphating. PMX structure had a large specific surface area and the dispersibility of PMX in the phosphating bath was higher than that of MXene. The phosphate coating obtained by introducing 0.025 g/L PMX (0.025-PMX coating) into the phosphating bath showed excellent comprehensive properties compared to past reports of nanomaterials used as accelerators since 2010. The phosphate coating was 81.52% heavier in mass per unit area and 98.93% lower in porosity than the pure phosphate coating. Furthermore, electrochemical impedance spectroscopy (EIS) data showed that the |Z0.01 Hz| of 0.025-PMX coating was approximately two orders of magnitude higher than that of the pure coating. Subse-quently, we proposed a mechanism for the positive impact of trace amounts of PMX nanosheets on phosphate coatings. This study demonstrates the importance of further studying nanomaterials as phosphating accelerators.

Automated summary

In this study, MXene nanosheets were functionalized by polydopamine to fabricate MXene@PDA (PMX) hybrid nanomaterial. The PMX structure had a large specific surface area and higher dispersibility in the phosphating bath compared to MXene. The phosphate coating obtained by introducing 0.025 g/L PMX showed excellent comprehensive properties and higher impedance compared to the pure coating. The study highlights the importance of further investigating nanomaterials as accelerators for phosphating.