Abstract Graphene oxide (GO), as a layered two-dimensional nanomaterial, is usually considered as potential candidate of solid lubricant because of its unique physical, chemical, and mechanical properties. However, its tribological behaviors strongly relate to the lubrication environment and the interlayer bonding strength. In this work, a bio-inspired GO-Al3+ coating with nacre-like layer-by-layer compact structure is constructed by using aluminum ions (Al3+) as the cross-linkers. As a comparison, a GO-spin coating with the same thickness is also fabricated by means of spin coating technique. The results show that the lubrication performance of the GO-spin coating is strongly dependent on the environment conditions; namely, it has good lubrication property in air while fails in vacuum due to the lack of passivating species. For the GO-Al3+ coating, the introduction of Al3+ passivates the reaction sites on GO sheets, preventing lubrication failure of GO coating in vacuum. Besides, the introduction of Al3+ dramatically enhances the interlayer bonding strength of coating, which results in high efficiency of load transfer and improved mechanical properties, therefore reducing wear loss with a thinner transfer film both in air and vacuum environments.

中文翻译：

---

通过铝离子的强化学键和反应位点钝化GO-Al3+涂层在空气和真空中的稳定润滑

摘要 氧化石墨烯（GO）作为一种层状二维纳米材料，由于其独特的物理、化学和机械性能，通常被认为是固体润滑剂的潜在候选材料。然而，其摩擦学行为与润滑环境和层间结合强度密切相关。在这项工作中，通过使用铝离子 (Al3+) 作为交联剂构建了具有珍珠层状逐层致密结构的仿生 GO-Al3+ 涂层。作为对比，同样采用旋涂技术制备了同样厚度的 GO-旋涂。结果表明，GO-spin涂层的润滑性能强烈依赖于环境条件；即在空气中具有良好的润滑性能，而在真空中由于缺乏钝化物质而失效。对于 GO-Al3+ 涂层，Al3+ 的引入钝化了 GO 片上的反应位点，防止了真空中 GO 涂层的润滑失效。此外，Al3+的引入显着增强了涂层的层间结合强度，从而提高了载荷传递效率并改善了机械性能，从而在空气和真空环境中通过更薄的传递膜降低了磨损损失。