Abstract
Ultrafine nanoporous Cu was successfully fabricated through the dealloying of amorphous Ti60Cu40−xAux (x = 0, 1, 2 at%) ribbon alloys in 0.65 M HF solution under free immersion conditions. A bicontinuous nanoporous structure of Cu formed on Ti60Cu40, Ti60Cu39Au1 and Ti60Cu38Au2 ribbons with pore sizes of 134, 8.9 and 7.4 nm, respectively. The pore size of the nanoporous Cu dealloyed from Au-added alloys was more than one order smaller than that of the Ti–Cu alloy, which resulted from the 5-order decrease in the surface diffusivity through alloying of Au into Ti60Cu40 ribbons. The Au content increased rapidly during the dealloying process and eventually formed binary Cu–Au solid solution and Au nanoparticles. Modifying the surface diffusivity by adding Au made it possible for the formation of the ultrafine nanoporous Cu structure.
