Platinum hollow nanospheres with different shell thickness: Controllable synthesis and electrocatalyst for the oxidation of formic acid

Abstract

Pt hollow nanospheres with different shell thicknesses were synthesized by adjusting the amount of precursor H 2 PtCl 6 , using 120 nm of α -selenium colloids as the template, ascorbic acid as the reducing agent, and SDSN as stabilizing agent. The prepared platinum hollow spheres were drop-coated to modify the glassy carbon electrode (Pt hollow /GC) and used as the working electrode. Scanning electron microscope (SEM), high resolution transmission electron microscope (HR-TEM), energy dispersive X-ray spectrum (EDX), X-ray diffraction (XRD) and selected area electron diffraction (SAED) were used to determine the morphology and structure. The electrocatalytic oxidation behavior of formic acid on the modified electrodes was evaluated by cyclic voltammetry and chronoamperometry. The results show that the Pt hollow nanospheres have a uniform particle size and good dispersity. The shell of the spheres were made of Pt clusters of various size, showing the similar structure and propertie to that of the polycrystalline platinum. Hollow nanospheres showed different electrocatalytic activity on the oxidation formic acid at a different molar ratio between Se and Pt. The Pt hollow nanosphere with a molar ratio of 1:1.2 shows the highest activity, and is much more active than the electrodeposited Pt on glassy carbon surface. These provides theoretical and experimental conditions for the anode material of direct formic fuel cell, and has potential value of application.