Ni2+-Assisted Dealloying Strategy to Prepare Nanoporous Cu-Ni Alloys with Enhanced Corrosion Resistance

To address the challenges associated with preparation of nanoporous Cu-Ni (NP-CuNi) alloys containing high Ni concentrations, a Ni2+-assisted dealloying strategy is proposed. The proposed strategy involves a three-stage dealloying process primarily driven by dynamic Ni deposition/dissolution. The Ni concentration in NP-CuNi is tuned by altering the Ni content of the Cu-Mn precursor alloy and Ni2+ in a H2SO4 solution. The Ni concentration of the nanoporous Cu66.5Ni28.5Mn5 alloy prepared in a H2SO4 + NiSO4 solution is increased by 5.2 times compared to that of the alloy prepared in the H2SO4 solution alone. Moreover, the corrosion resistance test demonstrates a reduction in corrosion current density by 58.3% compared to NP-Cu.