Some Aspects on the One-Pot Fabrication of Nanoporous Pd–Au Surface Films by Electrochemical Alloying/Dealloying of (Pd–Au)–Zn from a Chlorozincate Ionic Liquid

摘要

The high thermal stability of the Lewis acidic ZnCl_(2)-1-ethyl-3-methylimidazolium chloride ionic liquid enables the in situ fabrication of hierarchical nanostructured Pd–Au bimetallic surfaces via electrochemical alloying/dealloying of (PdAu)Zn on PdAu substrate in the ionic liquid. Nanostructured PdAu samples that consist of patterned cracks and ligaments are fabricated by using potential cycling method and constant-potential electrolysis method, respectively. The effects of working temperature and amounts of the deposited Zn on the morphology of the dealloyed (PdAu)Zn nanostructure are examined. The formation of the hierarchical nanostructure is a compromise between high-surface-diffusive Au and low-surface-diffusive Pd. Whereas Au in the alloy promotes the nanostructure formation, Pd in the PdAu nanostructure protects this material from coarsening. Compared with the plain PdAu, the nanostructured PdAu surface prepared at 150 °C exhibits a significantly higher active surface area and a high capability for the electro-oxidation of glucose.