A Metal-on-Metal Growth Approach to Metal-Metal Oxide Core- Shell Nanostructures with Plasmonic Properties

Hybrid core-shell nanoparticles integrate the material properties from individual components; however, the synthesis of core-shell nanoparticles with dissimilar materials remains challenging. In this work, we applied a metal-on-metal thin film growth approach to control the conformal deposition of non-precious metal shells on the Cu-based metal cores to form core-shell structures of metal-metal oxide hybrids (M-M'O-x, where M = AuCu3 or Cu, M' = Fe, Mn, and Ni). The deposition kinetics were controlled by a temperature-regulated thermal decomposition of zerovalent transition metal complexes. It is predicted that the conformal deposition can be promoted by keeping the initial op , I=t1c ED%mapping deposition temperature close to the thermal decomposition temperature -0,er- Fe Me of the zerovalent precursors. The mechanisms of strain reduction and interdiffusion facilitate conformal deposition over island growth in the synthesis with slow reaction kinetics. This study provides insightful guidance to metal-on-metal growth in solution at the nanoscale and thus the seed-mediated approach to hybrid core-shell structures. The optical properties of these metal-metal oxide hybrids were investigated experimentally and interpreted by theoretical simulations. Despite damping effects, the plasmonic properties of these Cu-based core-metal oxide shell structures may have the potential to enable plasmon-enhanced applications.