Refinement of Nanoporous Copper: A Summary of Micro-Alloying of Au-Group and Pt-Group Elements

Abstract

The micro-alloying of 1at% metals of Au-Group (Ag, Au) and the Pt-Group (Ni, Pd, Pt) with the Ti60Cu40 amorphous alloy resulted in the formation of fine nanoporous copper (NPC) in the order of 6­28nm. The smallest characteristic pore size of open­cell nanoporous fcc Cu was 7 and 6nm after dealloying the amorphous Ti60Cu39Pd1 and Ti60Cu39Pt1 precursor alloys for 43.2ks in 0.03M HF solution, while NPC had a pore size of 39nm after dealloying the amorphous Ti60Cu40 precursor alloy. On the basis of TEM micrographs, the refining factor increased approximately from 4 for the Ti60Cu39Ag1 precursor alloy to 1780 for the Ti60Cu39Pt1 precursor alloy. The refinement was attributed to the dramatic decrease in the surface diffusivity during dealloying. The refinement efficiency of the micro-alloying of the Pt-group elements was higher than that of the Au-group elements. The homogeneous distribution of additives in both of the amorphous precursor alloys and the final stabilized NPCs played a key role in refining the NPCs. This strategy may contribute to the fabrication of cost-effective nanoporous metals with a nanoporosity comparable to that of nanoporous Au, Pd and Pt catalysts. [doi:10.2320/matertrans.M2013445]