Facile fabrication of 3D dendritic gold nanostructures with an AuSn alloy by square wave potential pulse

Multifunctional three dimensional (3D) dendritic gold (DG) nanostructures have been synthesized facilely by square wave potential pulse (SWPP) with an Au45Sn55 (wt.%) alloy in an electrolyte of NaOH or H2SO4. The dendrite formation involves combined actions of selective removal of Sn, oxidation-reduction cycles (ORCs) of gold and intensive hydrogen evolution, wherein the nanopores from dealloying and the movement of hydrogen bubbles facilitate the dendrite formation by rearranging the newly produced Au atoms from the ORCs. An alkaline medium is preferable and the dendritic structure can be obtained as quickly as in 100 s. Some applications have been demonstrated with the prepared DG including electrocatalytic oxidation of glucose, surface-enhanced Raman scattering, and superhydrophobicity.