Concentration-dependent platinum nanoassemblies with morphology-controlled electroactivity and high durability for direct methanol fuel cells

Abstract

Platinum (Pt) nanoassemblies with different morphologies, such as nanospheres self-assembled by nanoparticles, multipolyhedral nanostructures built with octahedral nanocrystals, hollow nanospheres consisted of armed nanoparticles, and two dimensional array arranged by nanocubes, were synthesized in solvothermal approach. The concentration gradient of Pt monomers plays a key role in the architecture of the self-assembled nanostructures, which is attributed to the weak dissolution of Pt precursor in high-viscosity solvent. In consequence, the electrode prepared by hollow Pt nanospheres consisted of armed nanoparticles shows much higher performance in the process of methanol electrooxidation than that of others. Meanwhile, the electrodes prepared by these novel Pt nanoassemblies are revealed longterm durability for methanol electro-oxidation, compared to the electrode prepared by monodispersed Pt nanoparticles.