Nanoporous Copper Fabricated by Dealloying Mn–Cu Precursors with Minor Nickel Element Addition and Heat Treatment Coarsening

Abstract

Nanoporous copper (NPC) and nanoporous copper-nickel (NPC-Ni) can be prepared by free corrosion dealloying Mn[Formula: see text]Cu[Formula: see text]Nix ([Formula: see text], 1, 3[Formula: see text]at.% Ni) precursor alloys. Microscopic morphology characterization by scanning electron microscopy exhibited a three-dimensional bicontinuous porous structure with nanoscale ligaments and pores. NPC with a pore size of 48.7[Formula: see text]nm was obtained in 0.1[Formula: see text]M hydrochloric acid solution for 3.5[Formula: see text]h dealloyed at 25[Formula: see text]C. Under the same free corrosion dealloying condition, NPC-Ni1 and NPC-Ni3 were obtained with the pore size of 36.6[Formula: see text]nm and 28.1[Formula: see text]nm, respectively. The results indicate that minor Ni atoms addition to the precursor greatly refined the dealloyed nanoporous structure. This effect could be attributed to the lower Ni surface diffusivity than that of Cu and resulted in slow down of the diffusion and rearrangement of Cu atoms during dealloying process. Post-dealloying heat treatment at 300[Formula: see text]C, 450[Formula: see text]C and 600[Formula: see text]C made the ligaments coarsen in NPC and NPC-Ni.