Effect of dealloying process on purity of nanoporous copper

Nanoporous Cu is synthesized by dealloying Mn-Cu precursors with the selective corrosion. The effects of time of heat treatment，the corrosion time and the temperature of dealloying on the porous morphology and the residual Mn content are investigated. It is revealed that the heat treatment can drive the composition to distribute homogeneously in the bulk alloy with increasing the time and consequently results in more fully dealloying for forming nanoporous Cu. There is no distinct decrease of the residual Mn content in the nanoporous Cu made from 95 h-heat-treated precursors with increasing the corrosion time. The residual Mn content in nanoporous Cu decreases from 3.54% at 25 ℃ corrosion temperature to 1.14% at 60 ℃ corrosion temperature. But the pore and the ligament sizes of the samples obviously coarsen after60 ℃ corrosion of the samples, and the samples are frangible. The resultant nanoporous copper possesses uniform porous structure in the three-dimensional network, with the residual Mn content of 1.23% and the average pore size of 40 nm.