Controlled Growth of Pt–Au Alloy Nanowires and Their Performance for Formic Acid Electrooxidation

Pt–Au alloy nanowires have been controllably electrodeposited on microelectrodes by applying an alternating current and were used as the electrocatalyst for formic acid oxidation. The frequency and voltage of the alternating current and the electrolyte composition were adjusted to precisely control the morphologies, alloying structures and composition. The characteristics of Pt–Au alloy nanowires were analyzed by scanning electron microscopy, X-ray diffraction and transmission electron spectroscopy. Electrocatalytic performance of formic acid oxidation at Pt–Au alloy nanowires electrode was investigated by cyclic voltammetry and chronoamperometry. The results showed that the Pt–Au alloy nanowires possessed highly-crystalline morphologies, the controllable bimetallic composition and single-phase alloy structures, which mainly grow in the <111> crystal orientation. The electrocatalytic activity of formic acid oxidation strongly depended on the bimetallic Pt/Au composition. The Pt35Au65 alloy nanowires displayed superior electrocatalytic performance and high stability toward the electrooxidation of formic acid in acidic solution, owing to the ensemble effect of the Pt and Au components. These findings provided insights into the design of the Pt–Au bimetallic nanomaterials as electrocatalysts for formic acid oxidation.