Superlubricity has recently raised an increasing interest owing to its great potential in energy saving and environmental benefits. Yet how to obtain stable superlubricity under an ultrahigh contact pressure (>1 GPa) still remains a challenge. Here, we demonstrate that robust liquid superlubricity can be realized even under a contact pressure of 1193 MPa by lubrication with partially oxidized black phosphorus (oBP) nanosheets. The analysis indicates that the oBP nanosheets that absorb large amounts of water molecules are retained at the friction interface and transform the friction pairs interface to that between the oBP nanosheets. Molecular dynamics simulation demonstrates that water molecules could be retained at the friction interface even under the ultrahigh contact pressure owing to the abundant P=O and P–OH bonds formed on the oBP nanosheet surfaces, contributing to the achievement of stable superlubricity under the ultrahigh contact pressure. This work has the potential of introducing the liquid superlubricity concept in diverse industrial applications involving high-contact-pressure operating conditions.

超级润滑由于其在节能和环保方面的巨大潜力，最近引起了越来越多的关注。然而，如何在超高接触压力（> 1 GPa）下获得稳定的超润滑性仍然是一个挑战。在这里，我们证明即使在1193 MPa的接触压力下，通过用部分氧化的黑磷（oBP）纳米片进行润滑，也可以实现强大的液体超润滑性。分析表明，吸收大量水分子的oBP纳米片保留在摩擦界面处，并将摩擦对界面转变为oBP纳米片之间的界面。分子动力学模拟表明，由于在oBP纳米片表面上形成了丰富的P = O和P-OH键，即使在超高接触压力下，水分子也可以保留在摩擦界面上，从而有助于在超高接触下实现稳定的超润滑性压力。这项工作有可能在涉及高接触压力操作条件的各种工业应用中引入液体超润滑性概念。