(Invited) Making Nanostructured Composites Via Inner-Pore Electrodeposition into Nanoporous Metals

Abstract

The selective removal of Ag from a solid solution of Ag-Au or Ag-Au-Pt yields a 3D bicontinuous, open-pore, nanoporous gold substrate (NPG), that is rich in the more noble metal(s)1 (Au and/or Pt). NPG has been successfully developed by the intelligent use of the conventionally-undesired dealloying corrosion. The excellent properties of NPG are attributed to the surface area-to-volume ratio, and high curvature of nanoligament surfaces2,3 . While a lot of recent research has been focusing on the structure/property relationships of NPG as a functional material in its own right4,5, the further use of NPG as a sophisticated template for fabricating complex nanostructured materials is worthy of attention.Previous work on atom probe tomography characterization of NPG6,7 showed the successful inner-pore electrodeposition of a fully compact Cu support, thus, opening the door to implementing that newly developed method to the creation of finely tuned nanostructures, using NPG as a template. Fabrication of functional nanostructures pertaining to the interests of the catalysis and mechanics communities will be demonstrated through the electrodeposition of Cu and Co on NPG. Key aspects that enable this unexpected complete infiltration of NPG layer will be highlighted including, a characteristic "subpotential" curvature-driven electrodeposition regime8. Insights on the associated electrodeposition mechanisms are gained through the pairing of electrochemical methods and high-resolution characterization techniques. Furthermore, recent advances in structural and chemical modifications that increase the complexity and tunability of NPG-based nanocomposites will be discussed for the first time. References Newman, R. C. 2.05 - Dealloying. in Shreir’s Corrosion (eds. Cottis, B. et al.) 801–809 (Elsevier, 2010).Zielasek, V. et al. Gold Catalysts: Nanoporous Gold Foams. Angewandte Chemie International Edition 45, 8241–8244 (2006).Xue, Y., Markmann, J., Duan, H., Weissmüller, J. & Huber, P. Switchable imbibition in nanoporous gold. Nature Communications 5, (2014).Wittstock, A., Wichmann, A., Biener, J. & Bäumer, M. Nanoporous gold: A new gold catalyst with tunable properties. Faraday Discuss (2011) doi:10.1039/c1fd00022e.Li, X. et al. Nanoporous-Gold-Based Hybrid Cantilevered Actuator Dealloyed and Driven by A Modified Rotary Triboelectric Nanogenerator. Sci Rep (2016) doi:10.1038/srep24092.El-Zoka, A. A., Langelier, B., Botton, G. A. & Newman, R. C. Enhanced analysis of nanoporous gold by atom probe tomography. Mater Charact 128, (2017).El-Zoka, A. A., Langelier, B., Korinek, A., Botton, G. A. & Newman, R. C. Nanoscale mechanism of the stabilization of nanoporous gold by alloyed platinum. Nanoscale 10, (2018).Lee, L., He, D., Carcea, A. G. & Newman, R. C. Exploring the reactivity and nanoscale morphology of de-alloyed layers. Corros Sci 49, 72–80 (2007).