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 Cu_66.5Ni_28.5Mn₅ 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.