Molten salt medium synthesis of wormlike platinum silver nanotubes without any organic surfactant or solvent for methanol and formic acid oxidation

Abstract

In the current research, the Pt_xAg_y (x/y = 86/14, 79/21, 52/48, 21/79, 11/89) nanoparticles (NPs) are synthesized in the KNO₃–LiNO₃ molten salts without using any organic surfactant or solvent. The SEM results suggest that when the content of Ag is higher than 48%, the wormlike Pt_xAg_y nanotubes (NTs) can be synthesized. The diameter of the Pt_xAg_yNTs shows a slow decrease with the increase of Ag content. The TEM and HRTEM results indicate that the growth of hollow Pt_xAg_y NTs undergoes an oriented attachment process and a Kirkendall effect approach. The results of cyclic voltammetry (CV) measurement indicate that the Pt₅₂Ag₄₈ catalyst presents a remarkable enhancement for methanol electrooxidation, while the Pt₈₆Ag₁₄ catalyst prefers electrochemically oxidizing formic acid compared with that of the commercially available Pt black.