Nanoporous metals prepared by dealloying have attracted increasing attention due to their interesting size-dependent physical, chemical, and biological properties. However, facile fabrication of metallic ultrathin freestanding nanoporous films (UF-NPFs) by dealloying is still challenging. Herein, we report a novel strategy of facile preparation of flexible Cu, Cu₃Ag, and CuAg UF-NPFs by dealloying thick Mg-Cu(Ag)-Gd metallic glass ribbons. During dealloying, the local reaction latent heat-induced glass transition of the precursor ribbons leads to the formation of a solid/liquid interface between the initially dealloyed nanoporous layer and the underlying supercooled liquid layer. Due to the bulging effect of in situ generated H₂ on the solid/liquid interface, Cu, Cu₃Ag, and CuAg UF-NPFs with thicknesses of ∼200 nm can self-peel off from the outer surface of the dealloying ribbons. Moreover, it was found that the surface-enhanced Raman scattering (SERS) detection limit of Rhodamine 6G (R6G) on the Cu and CuAg UF-NPF substrates are 10⁻⁶ M and 10⁻¹¹ M, respectively, which are lower than most of the Cu and Cu-Ag substrates prepared by other methods. This work presents a reliable simple strategy to synthesize a variety of cost effective and flexible metallic UF-NPFs for functional applications.

通过脱合金制备的纳米多孔金属由于其有趣的尺寸依赖性的物理，化学和生物学特性而引起了越来越多的关注。然而，通过脱合金来容易地制造金属超薄独立纳米孔膜（UF-NPF）仍然具有挑战性。在这里，我们报告了一种新的策略，即通过脱合金厚的Mg-Cu（Ag）-Gd金属玻璃带轻松制备柔性Cu，Cu ₃ Ag和CuAg UF-NPF。在脱合金期间，前体带的局部反应潜热诱导的玻璃化转变导致在最初脱合金的纳米多孔层和下面的过冷液体层之间形成固/液界面。由于原位生成的H ₂在固/液界面Cu，Cu ₃上的膨胀作用厚度约为200 nm的Ag和CuAg UF-NPF可以从脱合金色带的外表面自动剥离。此外，发现在Cu和CuAg UF-NPF基板上若丹明6G（R6G）的表面增强拉曼散射（SERS）检测极限分别为10 ^-6  M和10 ^-11  M，低于大多数用其他方法制备的铜和铜-银基材。这项工作提出了一种可靠的简单策略，可以合成用于功能应用的各种低成本，灵活的金属UF-NPF。