Synthesis\nof Vertically Conformal ZnO/CuO Core–Shell Nanowire Arrays\nby Electrophoresis-Assisted Electroless Deposition

Abstract

Vertically\nconformal ZnO/CuO core–shell nanowire (NW) arrays with high\naspect ratios were synthesized by electrophoresis-assisted electroless\ndeposition (EAELD) of CuO onto preformed ZnO NWs. Using this method,\nconformal CuO seeds were successfully formed on long ZnO NWs by the\nelectrostatic attachment of colloidal Cu₂O NPs under the\nsolution and subsequent thermal oxidation. Using the CuO seeds, conformal\nCuO shell to core ZnO NWs were successfully fabricated by kinetic-limited\ndeposition in the solution, which overcame the inherent diffusion\nlimitations of conventional electroless deposition. This experimental\nevidence and thermodynamic modeling results are presented to validate\nthe proposed EAELD mechanism. The vertically conformal hetero-nanostructure\narrays developed in this work are a promising platform for applications\nsuch as solar cells and catalysts because of the maximized junction\nareas and active sites.