The present invention relates to a method for preparing a metallized open-cell foam or fibrous substrate, wherein the method comprises: (A) providing an open-cell foam or fibrous substrate, wherein the open-cell foam or fibrous substrate contains a polymer comprising heteroatom-containing moieties within the bulk of the open-cell foam or fibrous substrate or as a coating on the open-cell foam or fibrous substrate, wherein the polymer comprising heteroatom-containing moieties is selected from polyvinylpyridine, polyvinylpyrrolidone, polyvinyl alcohol, polyallylamine, polyethylene oxide, polyethylene imine, polyethylene sulfide and copolymers or blends thereof (B) contacting the open-cell foam or fibrous substrate with nanoparticles of a first metal to provide a nanoparticle coated open-cell foam or fibrous substrate and (C) contacting the nanoparticle coated open-cell foam or fibrous substrate with a solution comprising a salt of a second metal and a reducing agent to provide the metallized open-cell foam or fibrous substrate having a layer of the second metal on the nanoparticle coated open-cell foam or fibrous substrate.
