Effect of preparation conditions on morphology and thermal stability of nanoporous copper

Nanoporous copper (NPC) was prepared by dealloying the as-cast Zn50Cu50, Zn60Cu40, Zn70Cu30 and Zn80Cu20 alloys in NH4Cl + HCl and HCl solutions. The results show that Zn70Cu30 alloy is the best precursor to form NPC with uniform structures. The addition of NH4Cl into HCl aqueous solution increases the corrosion rate, which favors the fabrication of uniform porous structures. A solution of 1 M NH4Cl + HCl is suitable for dealloying Zn70Cu30 alloy. To reduce the shale-defects, the Zn70Cu30 alloy should be annealed at 530 °C. The NPC fabricated by dealloying Zn70Cu30 precursor (annealed at 530 °C) in NH4Cl + HCl solution has better thermal stability.

► Bulk nanoporous copper (NPC) was prepared by dealloying Zn–Cu alloys.
► Zn70Cu30 alloy annealed at 530 °C is an appropriate precursor.
► Addition of NH4Cl into HCl dealloying solution favors the formation of uniform porous structures.
► Bulk NPC with uniform structures has better thermal stability.