Electrodeposition of Pt nanoparticles on undoped nanodiamond powder for methanol oxidation electrocatalysts

Undoped nanodiamond (ND) powder with average particle sizes of 5 and 100 nm were modified with platinum (Pt) nanoparticles by electrodeposition from 1.1 mM chloroplatinic acid solution. The structure and morphology of the composites were characterized by field emission-scanning electron microscopy and X-ray diffraction. The results showed that Pt nanoparticles were well-dispersed on the facet surfaces of ND particles. The electrooxidation of methanol on Pt-modified ND powders was investigated by cyclic voltammetry, which indicated its good electrocatalytic activity. Compared with 100 nm ND powder, the 5 nm ND powder modified with Pt nanoparticles exhibited better electrocatalytic activity.