“Re-growth Etching” to Large-sized Porous Gold Nanostructures

A new method, named “re-growth etching”, which introduces a unique etchant “Au(I)”, has been developed to fabricate large-sized porous gold nanostructures. The size of nanostructures and the number of pores can be regulated by the molar ratio of Ag and Au in the precursor. We have evaluated their performance by a model reaction of the reduction of 4-nitrophenol. The catalytic property of porous Au from Ag(67.6)Au(32.4) (Sample 3) is higher than those of other obtained products, which are mainly attributed to its hollows-interior, porous-exterior, and the large amount of Au. The method for the large-sized porous metal nanostructures has been established for the first time and shows the potential of this route to expand the scope of fabricating porous metal nanostructures.