Toward Bimetallic Nanowire Arrays with Controlled Compositions Using Block Copolymer Films: The Interplay Between Metal Precursors

Metallic nanowire (NW) arrays are promising components for nanotechnology owing to their elongated, continuous, and directional structure. Bimetallic NWs present synergistic effects that are advantageous for applications in catalysis and magnetism. Yet, creating bimetallic NW arrays requires concomitant control over composition and organization. Block copolymer films, which exhibit periodic arrays of nano-domains, provide templates that satisfy this requirement. Impregnating the film using two metal precursors followed by plasma treatment enabled us to prepare NW arrays with different bimetallic compositions. The NW composition was found to depend on the composition of the impregnation solution in a nontrivial way, which was strongly influenced by the type of metals used. Studying the behavior of three model metal pairs unraveled different characteristic co-impregnation behaviors, which we could associate with metal-ligand and metal-metal interactions. The insights gained in this study allow us to create bimetallic NW arrays with compositions tailored to the desired properties.