The Dynamic Interfacial Understanding of Zinc Electrodeposition in Ammoniacal Media through Synchrotron Radiation Techniques

Abstract

Resorted to the advanced synchrotron radiation techniques, the interfacial evolution behaviors of zinc electrodeposits from ammonium chloride media have been disclosed using ex situ X-ray absorption spectroscopy (XAS) and real-time dynamic X-ray imaging (DXI). The XAS spectra indicate that the predominant zinc(II) species in ammonium chloride media present a tetrahedral configuration independent on aqueous pH. However, the DXI results suggest that the diverse morphologies of zinc deposits are highly dependent on aqueous pH due to the change of inner coordination sphere of zinc species. Moreover, the anodic stripping of zinc deposits firstly results from the dissolution of compact deposits at the substrate side. These observations provide a deep interfacial insight on zinc electrodeposition in ammonium chloride media, thereby allowing the morphologies of metal electrodeposits to be better regulated through the change of solution chemistry.