Capillary action-induced nanosurface infiltration for vacuum-assisted graphene oxide coating in bronze protection

Abstract Ancient artifacts like bronze often suffer corrosion from water and soil, requiring effective surface coatings to prevent further decay. Herein, we developed a vacuum-assisted method to prevent bronzes as a model from surface corrosion. The graphene oxide (GO)-based coatings can be toughly infiltrated into the rough bronze surfaces with freezing drying. Scanning transmission electron microscopy and energy dispersive X-ray spectroscopy demonstrate the advantages of this method in micro-nano coating protection, namely, the complete coating covering the crack channels. The coated bronze still has a lower corrosion rate than the uncoated sample, confirmed by electrochemical methods under 3 wt.% NaCl solutions. Focused ion beam cross-section imaging confirms a continuous protective layer in the coated sample, contrasting with the compact oxide layer on uncoated bronze. This method offers a promising solution for the sustainable preservation of bronze artifacts and other metal relics.