An efficient PDA/Al2O3 nanosheets reinforced ultra-thin ZrO2 coating with attractive anti-corrosion and deuterium resistance property

Two-dimensional materials, impermeable to various mediums, have ignited the great interest in developing multifunction nanocomposite coatings. Even though Al 2 O 3 has excellent thermal and chemical stability, it is hard to obtain Al 2 O 3 nanosheets from their non-lamellar structured bulk counterparts. In this work, we have developed a bottom–up strategy to synthesize several-nanometer thick Al 2 O 3 nanosheets by taking graphene oxide as the templates, and further improved their dispersibility by modifying them with poly-dopamine (PDA). These PDA-modified Al 2 O 3 nanosheets were then successfully integrated into the nanosized ZrO 2 coating to enhance its anti-corrosion and gas permeation reduction properties. With the Al 2 O 3 nanosheets inserted, corrosion resistance and deuterium resistance of the ZrO 2 coating were increased by 1000% and 1557%, respectively, both of which were above two orders of magnitude higher than that of the 321 steel substrate. The significant improvements achieved by Al 2 O 3 nanosheets demonstrate their capacity to effectively block the diffusion of both ions and deuterium atoms. This work not only offers a new platform for fabricating nanosheets from non-lamellar structured materials, but also indicates tremendous potential of Al 2 O 3 nanosheets as a novel filler for developing high-performance functional coatings.