The high reductivity of aluminum (Al) implies the utmost difficulty in achieving oxygen-resistant, ultrathin Al nanostructures. Herein, we demonstrate that sub-2-nm-thick Al nanosheets with ambient stability can be synthesized through a facile wet-chemical approach. Selective oxygen adsorption on the (111) facets of the face-centered cubic (fcc) Al has been revealed as the reason of controlling the morphology and stability of Al nanosheets, tailoring the thickness from 18 nm to 1.5 nm. Within the (111) surface passivation, Al nanosheets have achieved satisfactory stability, ensuring the possibility to study thickness-dependent localized surface plasmon resonance from visible to near-infrared (near-IR) region, and significantly enhanced two-photon luminescence. This work demonstrates, for the first time, the feasibility in obtaining stable ultrathin nanostructures of Al metal, which paves the way toward optical applications of Al as a sustainable plasmonic material, and shows great potential in the synthesis of other active metal-based nanomaterials.

铝（Al）的高还原性意味着获得耐氧的超薄Al纳米结构的最大困难。在这里，我们证明可以通过一种简便的湿化学方法合成具有环境稳定性的亚2纳米厚的Al纳米片。面心立方（fcc已经揭示出铝是控制Al纳米片的形态和稳定性的原因，其将厚度从18nm调整为1.5nm。在（111）表面钝化中，Al纳米片获得了令人满意的稳定性，从而确保了研究从可见光到近红外（near-IR）区域的依赖厚度的局部表面等离振子共振的可能性，并显着增强了两个光子的发光。这项工作首次证明了获得稳定的Al金属超薄纳米结构的可行性，这为将Al作为可持续的等离子体材料的光学应用铺平了道路，并在合成其他基于活性金属的纳米材料中显示出巨大的潜力。