Dual-phase nanostructuring as a route to flexible nanoporous metals with outstanding comprehensive mechanical properties

The mechanical properties of nanoporous metals(NPMs)are very important for their potential applications in flexible electronics.Here,the NP Cu@Zr-Cu-Al metallic glass(NP Cu@Zr-Cu-Al MG)composite with high strength,high hardness,and good flexibility is reported.The NP Cu@Zr-Cu-Al MG was synthesized by a two-step dealloying method.First,the flexible NP Zr-Cu-Al MG was prepared by selective etching the active Y-rich MG from the pseudobinary MG system(Zr_(47)Cu_(46)Al_(7)MG+Y_(47)Cu_(46)Al_(7)MG)of Cu46Zr23.5-Y23.5Al7 alloy.The NP Cu@Zr-Cu-Al MG was then obtained by further etching the NP Zr-Cu-Al MG and the Cu layer was evenly covered on the MG matrix of ligaments.The NP Cu@Zr-Cu-Al MG demonstrated good flexibility due to its non-cracking structure and the existence of flexible Zr-Cu-Al MG.Additionally,the NP Cu@Zr-Cu-Al MG showed the highest tensile strength of 143.9 MPa and nanohardness of0.79 GPa among all the reported NPMs.The Zr-Cu-Al MG strengthening phase weakened the rupture of Cu@Zr-Cu-Al ligaments,which could effectively restrain the crack initiation and propagation in the NP Cu@Zr-Cu-Al MG.Finally,it could improve the comprehensive mechanical properties.The NP Cu@Zr-Cu-Al MG was applied as an electrode for supercapacitors and glucose biosensors.The NP Cu@Zr-Cu-Al MG electrode displayed better conductivity and supercapacitor capacitance than the bare NP Zr-Cu-Al MG electrode.